Increased API readability

- Removed Abstract*Job hierarchy
- Introduced EntityRetrievers
- Introduced JobPager
- Moved files around

src/Api/Api.php

@@ -33,12 +33,12 @@ final class Api
 		return $statuses;
 	}
 
-	public static function checkArguments(AbstractJob $job)
+	public static function checkArguments(IJob $job)
 	{
 		self::runArgumentCheck($job, $job->getRequiredArguments());
 	}
 
-	public static function checkPrivileges(AbstractJob $job)
+	public static function checkPrivileges(IJob $job)
 	{
 		if ($job->isAuthenticationRequired())
 			Access::assertAuthentication();
@@ -57,7 +57,7 @@ final class Api
 		}
 	}
 
-	private static function runArgumentCheck($job, $item)
+	private static function runArgumentCheck(IJob $job, $item)
 	{
 		if (is_array($item))
 			throw new Exception('Argument definition cannot be an array.');

src/Api/ApiJobUnsatisfiedException.php

@@ -1,7 +1,7 @@
 <?php
 class ApiJobUnsatisfiedException extends SimpleException
 {
-	public function __construct(AbstractJob $job, $arg = null)
+	public function __construct(IJob $job, $arg = null)
 	{
 		parent::__construct('%s cannot be run due to unsatisfied execution conditions (%s).',
 			get_class($job),

src/Api/Common/EntityRetrievers/CommentRetriever.php

@@ -0,0 +1,36 @@
+<?php
+class CommentRetriever implements IEntityRetriever
+{
+	private $job;
+
+	public function __construct(IJob $job)
+	{
+		$this->job = $job;
+	}
+
+	public function tryRetrieve()
+	{
+		if ($this->job->hasArgument(JobArgs::ARG_COMMENT_ENTITY))
+			return $this->job->getArgument(JobArgs::ARG_COMMENT_ENTITY);
+
+		if ($this->job->hasArgument(JobArgs::ARG_COMMENT_ID))
+			return CommentModel::getById($this->job->getArgument(JobArgs::ARG_COMMENT_ID));
+
+		return null;
+	}
+
+	public function retrieve()
+	{
+		$comment = $this->tryRetrieve();
+		if ($comment)
+			return $comment;
+		throw new ApiJobUnsatisfiedException($this->job);
+	}
+
+	public function getRequiredArguments()
+	{
+		return JobArgs::Alternative(
+			JobArgs::ARG_COMMENT_ID,
+			JobArgs::ARG_COMMENT_ENTITY);
+	}
+}

src/Api/Common/EntityRetrievers/IEntityRetriever.php

@@ -0,0 +1,8 @@
+<?php
+interface IEntityRetriever
+{
+	public function __construct(IJob $job);
+	public function tryRetrieve();
+	public function retrieve();
+	public function getRequiredArguments();
+}

src/Api/Common/EntityRetrievers/PostRetriever.php

@@ -0,0 +1,40 @@
+<?php
+class PostRetriever implements IEntityRetriever
+{
+	private $job;
+
+	public function __construct(IJob $job)
+	{
+		$this->job = $job;
+	}
+
+	public function tryRetrieve()
+	{
+		if ($this->job->hasArgument(JobArgs::ARG_POST_ENTITY))
+			return $this->job->getArgument(JobArgs::ARG_POST_ENTITY);
+
+		if ($this->job->hasArgument(JobArgs::ARG_POST_ID))
+			return PostModel::getById($this->job->getArgument(JobArgs::ARG_POST_ID));
+
+		if ($this->job->hasArgument(JobArgs::ARG_POST_NAME))
+			return PostModel::getByName($job->getArgument(JobArgs::ARG_POST_NAME));
+
+		return null;
+	}
+
+	public function retrieve()
+	{
+		$post = $this->tryRetrieve();
+		if ($post)
+			return $post;
+		throw new ApiJobUnsatisfiedException($this->job);
+	}
+
+	public function getRequiredArguments()
+	{
+		return JobArgs::Alternative(
+			JobArgs::ARG_POST_ID,
+			JobArgs::ARG_POST_NAME,
+			JobArgs::ARG_POST_ENTITY);
+	}
+}

src/Api/Common/EntityRetrievers/SafePostRetriever.php

@@ -0,0 +1,36 @@
+<?php
+class SafePostRetriever implements IEntityRetriever
+{
+	private $job;
+
+	public function __construct(IJob $job)
+	{
+		$this->job = $job;
+	}
+
+	public function tryRetrieve()
+	{
+		if ($this->job->hasArgument(JobArgs::ARG_POST_ENTITY))
+			return $this->job->getArgument(JobArgs::ARG_POST_ENTITY);
+
+		if ($this->job->hasArgument(JobArgs::ARG_POST_NAME))
+			return PostModel::getByName($this->job->getArgument(JobArgs::ARG_POST_NAME));
+
+		return null;
+	}
+
+	public function retrieve()
+	{
+		$post = $this->tryRetrieve();
+		if ($post)
+			return $post;
+		throw new ApiJobUnsatisfiedException($this->job);
+	}
+
+	public function getRequiredArguments()
+	{
+		return JobArgs::Alternative(
+			JobArgs::ARG_POST_NAME,
+			JobArgs::ARG_POST_ENTITY);
+	}
+}

src/Api/Common/EntityRetrievers/UserRetriever.php

@@ -0,0 +1,37 @@
+<?php
+class UserRetriever implements IEntityRetriever
+{
+	private $job;
+
+	public function __construct(IJob $job)
+	{
+		$this->job = $job;
+	}
+
+	public function tryRetrieve()
+	{
+		if ($this->job->hasArgument(JobArgs::ARG_USER_ENTITY))
+			return $this->job->getArgument(JobArgs::ARG_USER_ENTITY);
+
+		if ($this->job->hasArgument(JobArgs::ARG_USER_NAME))
+			return UserModel::getByNameOrEmail($this->job->getArgument(JobArgs::ARG_USER_NAME));
+
+		return null;
+	}
+
+	public function retrieve()
+	{
+		$user = $this->tryRetrieve();
+		if ($user)
+			return $user;
+		throw new ApiJobUnsatisfiedException($this->job);
+	}
+
+	public function getRequiredArguments()
+	{
+		return JobArgs::Alternative(
+			JobArgs::ARG_USER_NAME,
+			JobArgs::ARG_USER_EMAIL,
+			JobArgs::ARG_USER_ENTITY);
+	}
+}

src/Api/Common/JobPager.php

@@ -0,0 +1,50 @@
+<?php
+class JobPager
+{
+	private $job;
+
+	public function __construct(IJob $job)
+	{
+		$this->pageSize = 20;
+		$this->job = $job;
+	}
+
+	public function setPageSize($newPageSize)
+	{
+		$this->pageSize = $newPageSize;
+	}
+
+	public function getPageSize()
+	{
+		return $this->pageSize;
+	}
+
+	public function getPageNumber()
+	{
+		if ($this->job->hasArgument(JobArgs::ARG_PAGE_NUMBER))
+			return (int) $this->job->getArgument(JobArgs::ARG_PAGE_NUMBER);
+		return 1;
+	}
+
+	public function getRequiredArguments()
+	{
+		return JobArgs::Optional(JobArgs::ARG_PAGE_NUMBER);
+	}
+
+	public function serialize($entities, $totalEntityCount)
+	{
+		$pageSize = $this->getPageSize();
+		$pageNumber = $this->getPageNumber();
+
+		$pageCount = ceil($totalEntityCount / $pageSize);
+		$pageNumber = $this->getPageNumber();
+		$pageNumber = min($pageCount, $pageNumber);
+
+		$ret = new StdClass;
+		$ret->entities = $entities;
+		$ret->entityCount = $totalEntityCount;
+		$ret->page = $pageNumber;
+		$ret->pageCount = $pageCount;
+		return $ret;
+	}
+}

src/Api/Jobs/AbstractJob.php

@@ -1,5 +1,5 @@
 <?php
-abstract class AbstractJob
+abstract class AbstractJob implements IJob
 {
 	const CONTEXT_NORMAL = 1;
 	const CONTEXT_BATCH_EDIT = 2;
@@ -14,10 +14,7 @@ abstract class AbstractJob
 
 	public abstract function execute();
 
-	public function getRequiredArguments()
-	{
-		return null;
-	}
+	public abstract function getRequiredArguments();
 
 	public function getRequiredPrivileges()
 	{

src/Api/Jobs/CommentJobs/AbstractCommentJob.php

@@ -1,29 +0,0 @@
-<?php
-abstract class AbstractCommentJob extends AbstractJob
-{
-	protected $comment;
-
-	public function prepare()
-	{
-		if ($this->hasArgument(JobArgs::ARG_COMMENT_ENTITY))
-		{
-			$this->comment = $this->getArgument(JobArgs::ARG_COMMENT_ENTITY);
-		}
-		else
-		{
-			$commentId = $this->getArgument(JobArgs::ARG_COMMENT_ID);
-			$this->comment = CommentModel::getById($commentId);
-		}
-	}
-
-	public function getRequiredArguments()
-	{
-		return JobArgs::Conjunction(
-			JobArgs::Alternative(
-				JobArgs::ARG_COMMENT_ID,
-				JobArgs::ARG_COMMENT_ENTITY),
-			$this->getRequiredSubArguments());
-	}
-
-	public abstract function getRequiredSubArguments();
-}

src/Api/Jobs/CommentJobs/AddCommentJob.php

@@ -1,9 +1,16 @@
 <?php
-class AddCommentJob extends AbstractPostJob
+class AddCommentJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$user = Auth::getCurrentUser();
 		$text = $this->getArgument(JobArgs::ARG_NEW_TEXT);
 
@@ -21,9 +28,11 @@ class AddCommentJob extends AbstractPostJob
 		return $comment;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_TEXT;
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_TEXT);
 	}
 
 	public function getRequiredPrivileges()

src/Api/Jobs/CommentJobs/DeleteCommentJob.php

@@ -1,27 +1,35 @@
 <?php
-class DeleteCommentJob extends AbstractCommentJob
+class DeleteCommentJob extends AbstractJob
 {
+	protected $commentRetriever;
+
+	public function __construct()
+	{
+		$this->commentRetriever = new CommentRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->comment->getPost();
+		$comment = $this->commentRetriever->retrieve();
+		$post = $comment->getPost();
 
-		CommentModel::remove($this->comment);
+		CommentModel::remove($comment);
 
 		Logger::log('{user} removed comment from {post}', [
 			'user' => TextHelper::reprUser(Auth::getCurrentUser()),
 			'post' => TextHelper::reprPost($post)]);
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return null;
+		return $this->commentRetriever->getRequiredArguments();
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::DeleteComment,
-			Access::getIdentity($this->comment->getCommenter()));
+			Access::getIdentity($this->commentRetriever->retrieve()->getCommenter()));
 	}
 
 	public function isAuthenticationRequired()

src/Api/Jobs/CommentJobs/EditCommentJob.php

@@ -1,9 +1,16 @@
 <?php
-class EditCommentJob extends AbstractCommentJob
+class EditCommentJob extends AbstractJob
 {
+	protected $commentRetriever;
+
+	public function __construct()
+	{
+		$this->commentRetriever = new CommentRetriever($this);
+	}
+
 	public function execute()
 	{
-		$comment = $this->comment;
+		$comment = $this->commentRetriever->retrieve();
 
 		$comment->setCreationTime(time());
 		$comment->setText($this->getArgument(JobArgs::ARG_NEW_TEXT));
@@ -16,16 +23,18 @@ class EditCommentJob extends AbstractCommentJob
 		return $comment;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_TEXT;
+		return JobArgs::Conjunction(
+			$this->commentRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_TEXT);
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::EditComment,
-			Access::getIdentity($this->comment->getCommenter()));
+			Access::getIdentity($this->commentRetriever->retrieve()->getCommenter()));
 	}
 
 	public function isAuthenticationRequired()

src/Api/Jobs/CommentJobs/ListCommentsJob.php

@@ -1,10 +1,23 @@
 <?php
-class ListCommentsJob extends AbstractPageJob
+class ListCommentsJob extends AbstractJob implements IPagedJob
 {
+	protected $pager;
+
+	public function __construct()
+	{
+		$this->pager = new JobPager($this);
+		$this->pager->setPageSize(getConfig()->comments->commentsPerPage);
+	}
+
+	public function getPager()
+	{
+		return $this->pager;
+	}
+
 	public function execute()
 	{
-		$pageSize = $this->getPageSize();
-		$page = $this->getArgument(JobArgs::ARG_PAGE_NUMBER);
+		$pageSize = $this->pager->getPageSize();
+		$page = $this->pager->getPageNumber();
 		$query = 'comment_min:1 order:comment_date,desc';
 
 		$posts = PostSearchService::getEntities($query, $pageSize, $page);
@@ -17,17 +30,12 @@ class ListCommentsJob extends AbstractPageJob
 			$comments = array_merge($comments, $post->getComments());
 		CommentModel::preloadCommenters($comments);
 
-		return $this->getPager($posts, $postCount, $page, $pageSize);
+		return $this->pager->serialize($posts, $postCount);
 	}
 
-	public function getDefaultPageSize()
+	public function getRequiredArguments()
 	{
-		return intval(getConfig()->comments->commentsPerPage);
-	}
-
-	public function getRequiredSubArguments()
-	{
-		return null;
+		return $this->pager->getRequiredArguments();
 	}
 
 	public function getRequiredPrivileges()

src/Api/Jobs/CommentJobs/PreviewCommentJob.php

@@ -1,21 +1,27 @@
 <?php
 class PreviewCommentJob extends AbstractJob
 {
+	protected $commentRetriever;
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->commentRetriever = new CommentRetriever($this);
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
 		$user = Auth::getCurrentUser();
 		$text = $this->getArgument(JobArgs::ARG_NEW_TEXT);
 
-		if ($this->hasArgument(JobArgs::ARG_POST_ID))
+		$comment = $this->commentRetriever->tryRetrieve();
+		if (!$comment)
 		{
-			$post = PostModel::getById($this->getArgument(JobArgs::ARG_POST_ID));
+			$post = $this->postRetriever->retrieve();
 			$comment = CommentModel::spawn();
 			$comment->setPost($post);
 		}
-		else
-		{
-			$comment = CommentModel::getById($this->getArgument(JobArgs::ARG_COMMENT_ID));
-		}
 
 		$comment->setCommenter($user);
 		$comment->setCreationTime(time());
@@ -31,8 +37,8 @@ class PreviewCommentJob extends AbstractJob
 		return JobArgs::Conjunction(
 			JobArgs::ARG_NEW_TEXT,
 			JobArgs::Alternative(
-				JobArgs::ARG_COMMENT_ID,
-				JobArgs::ARG_POST_ID));
+				$this->commentRetriever->getRequiredArguments(),
+				$this->postRetriever->getRequiredArguments()));
 	}
 
 	public function getRequiredPrivileges()

src/Api/Jobs/IJob.php

@@ -0,0 +1,17 @@
+<?php
+interface IJob
+{
+	public function prepare();
+	public function execute();
+
+	public function getRequiredArguments();
+	public function getRequiredPrivileges();
+	public function isAuthenticationRequired();
+	public function isConfirmedEmailRequired();
+
+	public function getArgument($key);
+	public function getArguments();
+	public function hasArgument($key);
+	public function setArgument($key, $value);
+	public function setArguments(array $arguments);
+}

src/Api/Jobs/IPagedJob.php

@@ -0,0 +1,5 @@
+<?php
+interface IPagedJob
+{
+	public function getPager();
+}

src/Api/Jobs/LogJobs/GetLogJob.php

@@ -1,10 +1,23 @@
 <?php
-class GetLogJob extends AbstractPageJob
+class GetLogJob extends AbstractJob implements IPagedJob
 {
+	protected $pager;
+
+	public function __construct()
+	{
+		$this->pager = new JobPager($this);
+		$this->pager->setPageSize(getConfig()->browsing->logsPerPage);
+	}
+
+	public function getPager()
+	{
+		return $this->pager;
+	}
+
 	public function execute()
 	{
-		$pageSize = $this->getPageSize();
-		$page = $this->getArgument(JobArgs::ARG_PAGE_NUMBER);
+		$pageSize = $this->pager->getPageSize();
+		$page = $this->pager->getPageNumber();
 		$name = $this->getArgument(JobArgs::ARG_LOG_ID);
 		$query = $this->getArgument(JobArgs::ARG_QUERY);
 
@@ -31,17 +44,13 @@ class GetLogJob extends AbstractPageJob
 		$lineCount = count($lines);
 		$lines = array_slice($lines, ($page - 1) * $pageSize, $pageSize);
 
-		return $this->getPager($lines, $lineCount, $page, $pageSize);
+		return $this->pager->serialize($lines, $lineCount);
 	}
 
-	public function getDefaultPageSize()
-	{
-		return intval(getConfig()->browsing->logsPerPage);
-	}
-
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
 		return JobArgs::Conjunction(
+			$this->pager->getRequiredArguments(),
 			JobArgs::ARG_LOG_ID,
 			JobArgs::ARG_QUERY);
 	}

src/Api/Jobs/PageJobs/AbstractPageJob.php

@@ -1,42 +0,0 @@
-<?php
-abstract class AbstractPageJob extends AbstractJob
-{
-	protected $pageSize = null;
-
-	public abstract function getDefaultPageSize();
-
-	public function getPageSize()
-	{
-		return $this->pageSize === null
-			? $this->getDefaultPageSize()
-			: $this->pageSize;
-	}
-
-	public function setPageSize($pageSize)
-	{
-		$this->pageSize = $pageSize;
-		return $this;
-	}
-
-	public function getPager($entities, $entityCount, $page, $pageSize)
-	{
-		$pageCount = ceil($entityCount / $pageSize);
-		$page = min($pageCount, $page);
-
-		$ret = new StdClass;
-		$ret->entities = $entities;
-		$ret->entityCount = $entityCount;
-		$ret->page = $page;
-		$ret->pageCount = $pageCount;
-		return $ret;
-	}
-
-	public function getRequiredArguments()
-	{
-		return JobArgs::Conjunction(
-			JobArgs::ARG_PAGE_NUMBER,
-			$this->getRequiredSubArguments());
-	}
-
-	public abstract function getRequiredSubArguments();
-}

src/Api/Jobs/PageJobs/ListPostsJob.php

@@ -1,32 +0,0 @@
-<?php
-class ListPostsJob extends AbstractPageJob
-{
-	public function execute()
-	{
-		$pageSize = $this->getPageSize();
-		$page = $this->getArgument(JobArgs::ARG_PAGE_NUMBER);
-		$query = $this->getArgument(JobArgs::ARG_QUERY);
-
-		$posts = PostSearchService::getEntities($query, $pageSize, $page);
-		$postCount = PostSearchService::getEntityCount($query);
-
-		PostModel::preloadTags($posts);
-
-		return $this->getPager($posts, $postCount, $page, $pageSize);
-	}
-
-	public function getDefaultPageSize()
-	{
-		return intval(getConfig()->browsing->postsPerPage);
-	}
-
-	public function getRequiredSubArguments()
-	{
-		return JobArgs::ARG_QUERY;
-	}
-
-	public function getRequiredPrivileges()
-	{
-		return new Privilege(Privilege::ListPosts);
-	}
-}

src/Api/Jobs/PageJobs/ListTagsJob.php

@@ -1,30 +0,0 @@
-<?php
-class ListTagsJob extends AbstractPageJob
-{
-	public function execute()
-	{
-		$pageSize = $this->getPageSize();
-		$page = $this->getArgument(JobArgs::ARG_PAGE_NUMBER);
-		$query = $this->getArgument(JobArgs::ARG_QUERY);
-
-		$tags = TagSearchService::getEntities($query, $pageSize, $page);
-		$tagCount = TagSearchService::getEntityCount($query);
-
-		return $this->getPager($tags, $tagCount, $page, $pageSize);
-	}
-
-	public function getDefaultPageSize()
-	{
-		return intval(getConfig()->browsing->tagsPerPage);
-	}
-
-	public function getRequiredSubArguments()
-	{
-		return JobArgs::ARG_QUERY;
-	}
-
-	public function getRequiredPrivileges()
-	{
-		return new Privilege(Privilege::ListTags);
-	}
-}

src/Api/Jobs/PageJobs/ListUsersJob.php

@@ -1,30 +0,0 @@
-<?php
-class ListUsersJob extends AbstractPageJob
-{
-	public function execute()
-	{
-		$pageSize = $this->getPageSize();
-		$page = $this->getArgument(JobArgs::ARG_PAGE_NUMBER);
-		$filter = $this->getArgument(JobArgs::ARG_QUERY);
-
-		$users = UserSearchService::getEntities($filter, $pageSize, $page);
-		$userCount = UserSearchService::getEntityCount($filter);
-
-		return $this->getPager($users, $userCount, $page, $pageSize);
-	}
-
-	public function getDefaultPageSize()
-	{
-		return intval(getConfig()->browsing->usersPerPage);
-	}
-
-	public function getRequiredSubArguments()
-	{
-		return JobArgs::ARG_QUERY;
-	}
-
-	public function getRequiredPrivileges()
-	{
-		return new Privilege(Privilege::ListUsers);
-	}
-}

src/Api/Jobs/PostJobs/AbstractPostJob.php

@@ -1,35 +0,0 @@
-<?php
-abstract class AbstractPostJob extends AbstractJob
-{
-	protected $post;
-
-	public function prepare()
-	{
-		if ($this->hasArgument(JobArgs::ARG_POST_ENTITY))
-		{
-			$this->post = $this->getArgument(JobArgs::ARG_POST_ENTITY);
-		}
-		elseif ($this->hasArgument(JobArgs::ARG_POST_ID))
-		{
-			$postId = $this->getArgument(JobArgs::ARG_POST_ID);
-			$this->post = PostModel::getById($postId);
-		}
-		else
-		{
-			$postName = $this->getArgument(JobArgs::ARG_POST_NAME);
-			$this->post = PostModel::getByName($postName);
-		}
-	}
-
-	public function getRequiredArguments()
-	{
-		return JobArgs::Conjunction(
-			JobArgs::Alternative(
-				JobArgs::ARG_POST_ID,
-				JobArgs::ARG_POST_NAME,
-				JobArgs::ARG_POST_ENTITY),
-			$this->getRequiredSubArguments());
-	}
-
-	public abstract function getRequiredSubArguments();
-}

src/Api/Jobs/PostJobs/DeletePostJob.php

@@ -1,9 +1,16 @@
 <?php
-class DeletePostJob extends AbstractPostJob
+class DeletePostJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 
 		PostModel::remove($post);
 
@@ -12,16 +19,16 @@ class DeletePostJob extends AbstractPostJob
 			'post' => TextHelper::reprPost($post)]);
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return null;
+		return $this->postRetriever->getRequiredArguments();
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::DeletePost,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 
 	public function isAuthenticationRequired()

src/Api/Jobs/PostJobs/EditPostContentJob.php

@@ -1,9 +1,16 @@
 <?php
-class EditPostContentJob extends AbstractPostJob
+class EditPostContentJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 
 		if ($this->hasArgument(JobArgs::ARG_NEW_POST_CONTENT_URL))
 		{
@@ -26,11 +33,13 @@ class EditPostContentJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::Alternative(
-			JobArgs::ARG_NEW_POST_CONTENT,
-			JobArgs::ARG_NEW_POST_CONTENT_URL);
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::Alternative(
+				JobArgs::ARG_NEW_POST_CONTENT,
+				JobArgs::ARG_NEW_POST_CONTENT_URL));
 	}
 
 	public function getRequiredPrivileges()
@@ -39,6 +48,6 @@ class EditPostContentJob extends AbstractPostJob
 			$this->getContext() == self::CONTEXT_BATCH_ADD
 				? Privilege::AddPostContent
 				: Privilege::EditPostContent,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 }

src/Api/Jobs/PostJobs/EditPostJob.php

@@ -1,9 +1,16 @@
 <?php
-class EditPostJob extends AbstractPostJob
+class EditPostJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 
 		Logger::bufferChanges();
 
@@ -43,9 +50,9 @@ class EditPostJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return null;
+		return $this->postRetriever->getRequiredArguments();
 	}
 
 	public function getRequiredPrivileges()
@@ -54,6 +61,6 @@ class EditPostJob extends AbstractPostJob
 			$this->getContext() == self::CONTEXT_BATCH_ADD
 				? Privilege::AddPost
 				: Privilege::EditPost,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 }

src/Api/Jobs/PostJobs/EditPostRelationsJob.php

@@ -1,9 +1,16 @@
 <?php
-class EditPostRelationsJob extends AbstractPostJob
+class EditPostRelationsJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$relations = $this->getArgument(JobArgs::ARG_NEW_RELATED_POST_IDS);
 
 		$oldRelatedIds = array_map(function($post) { return $post->getId(); }, $post->getRelations());
@@ -32,9 +39,11 @@ class EditPostRelationsJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_RELATED_POST_IDS;
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_RELATED_POST_IDS);
 	}
 
 	public function getRequiredPrivileges()
@@ -43,6 +52,6 @@ class EditPostRelationsJob extends AbstractPostJob
 			$this->getContext() == self::CONTEXT_BATCH_ADD
 				? Privilege::AddPostRelations
 				: Privilege::EditPostRelations,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 }

src/Api/Jobs/PostJobs/EditPostSafetyJob.php

@@ -1,9 +1,16 @@
 <?php
-class EditPostSafetyJob extends AbstractPostJob
+class EditPostSafetyJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$newSafety = new PostSafety($this->getArgument(JobArgs::ARG_NEW_SAFETY));
 
 		$oldSafety = $post->getSafety();
@@ -23,9 +30,11 @@ class EditPostSafetyJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_SAFETY;
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_SAFETY);
 	}
 
 	public function getRequiredPrivileges()
@@ -34,6 +43,6 @@ class EditPostSafetyJob extends AbstractPostJob
 			$this->getContext() == self::CONTEXT_BATCH_ADD
 				? Privilege::AddPostSafety
 				: Privilege::EditPostSafety,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 }

src/Api/Jobs/PostJobs/EditPostSourceJob.php

@@ -1,9 +1,16 @@
 <?php
-class EditPostSourceJob extends AbstractPostJob
+class EditPostSourceJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$newSource = $this->getArgument(JobArgs::ARG_NEW_SOURCE);
 
 		$oldSource = $post->getSource();
@@ -23,9 +30,11 @@ class EditPostSourceJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_SOURCE;
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_SOURCE);
 	}
 
 	public function getRequiredPrivileges()
@@ -34,6 +43,6 @@ class EditPostSourceJob extends AbstractPostJob
 			$this->getContext() == self::CONTEXT_BATCH_ADD
 				? Privilege::AddPostSource
 				: Privilege::EditPostSource,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 }

src/Api/Jobs/PostJobs/EditPostTagsJob.php

@@ -1,9 +1,16 @@
 <?php
-class EditPostTagsJob extends AbstractPostJob
+class EditPostTagsJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$tagNames = $this->getArgument(JobArgs::ARG_NEW_TAG_NAMES);
 
 		if (!is_array($tagNames))
@@ -40,9 +47,11 @@ class EditPostTagsJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_TAG_NAMES;
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_TAG_NAMES);
 	}
 
 	public function getRequiredPrivileges()
@@ -51,6 +60,6 @@ class EditPostTagsJob extends AbstractPostJob
 			$this->getContext() == self::CONTEXT_BATCH_ADD
 				? Privilege::AddPostTags
 				: Privilege::EditPostTags,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 }

src/Api/Jobs/PostJobs/EditPostThumbJob.php

@@ -1,9 +1,16 @@
 <?php
-class EditPostThumbJob extends AbstractPostJob
+class EditPostThumbJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$file = $this->getArgument(JobArgs::ARG_NEW_THUMB_CONTENT);
 
 		$post->setCustomThumbnailFromPath($file->filePath);
@@ -18,9 +25,11 @@ class EditPostThumbJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_THUMB_CONTENT;
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_THUMB_CONTENT);
 	}
 
 	public function getRequiredPrivileges()
@@ -29,6 +38,6 @@ class EditPostThumbJob extends AbstractPostJob
 			$this->getContext() == self::CONTEXT_BATCH_ADD
 				? Privilege::AddPostThumb
 				: Privilege::EditPostThumb,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 }

src/Api/Jobs/PostJobs/FeaturePostJob.php

@@ -1,9 +1,16 @@
 <?php
-class FeaturePostJob extends AbstractPostJob
+class FeaturePostJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 
 		PropertyModel::set(PropertyModel::FeaturedPostId, $post->getId());
 		PropertyModel::set(PropertyModel::FeaturedPostUnixTime, time());
@@ -20,16 +27,18 @@ class FeaturePostJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::Optional(JobArgs::ARG_ANONYMOUS);
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::Optional(JobArgs::ARG_ANONYMOUS));
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::FeaturePost,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 
 	public function isAuthenticationRequired()

src/Api/Jobs/PostJobs/FlagPostJob.php

@@ -1,9 +1,16 @@
 <?php
-class FlagPostJob extends AbstractPostJob
+class FlagPostJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$key = TextHelper::reprPost($post);
 
 		$flagged = SessionHelper::get('flagged', []);
@@ -19,15 +26,15 @@ class FlagPostJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return null;
+		return $this->postRetriever->getRequiredArguments();
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::FlagPost,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 }

src/Api/Jobs/PostJobs/GetPostContentJob.php

@@ -1,19 +1,16 @@
 <?php
 class GetPostContentJob extends AbstractJob
 {
-	protected $post;
+	protected $postRetriever;
 
-	public function prepare()
+	public function __construct()
 	{
-		if ($this->hasArgument(JobArgs::ARG_POST_ENTITY))
-			$this->post = $this->getArgument(JobArgs::ARG_POST_ENTITY);
-		else
-			$this->post = PostModel::getByName($this->getArgument(JobArgs::ARG_POST_NAME));
+		$this->postRetriever = new SafePostRetriever($this);
 	}
 
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$config = getConfig();
 
 		$path = $config->main->filesPath . DS . $post->getName();
@@ -35,14 +32,12 @@ class GetPostContentJob extends AbstractJob
 
 	public function getRequiredArguments()
 	{
-		return JobArgs::Alternative(
-			JobArgs::ARG_POST_NAME,
-			JobArgs::ARG_POST_ENTITY);
+		return $this->postRetriever->getRequiredArguments();
 	}
 
 	public function getRequiredPrivileges()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$privileges = [];
 
 		if ($post->isHidden())

src/Api/Jobs/PostJobs/GetPostJob.php

@@ -1,23 +1,32 @@
 <?php
-class GetPostJob extends AbstractPostJob
+class GetPostJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 
 		CommentModel::preloadCommenters($post->getComments());
 
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return null;
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			null);
 	}
 
 	public function getRequiredPrivileges()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$privileges = [];
 
 		if ($post->isHidden())

src/Api/Jobs/PostJobs/GetPostThumbJob.php

@@ -1,13 +1,21 @@
 <?php
 class GetPostThumbJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new SafePostRetriever($this);
+	}
+
 	public function execute()
 	{
-		if ($this->getArgument(JobArgs::ARG_POST_NAME))
+		//optimize - save extra query to DB
+		if ($this->hasArgument(JobArgs::ARG_POST_NAME))
 			$name = $this->getArgument(JobArgs::ARG_POST_NAME);
 		else
 		{
-			$post = PostModel::getByName($this->getArgument(JobArgs::ARG_POST_ENTITY));
+			$post = $this->postRetriever->retrieve();
 			$name = $post->getName();
 		}
 
@@ -21,10 +29,7 @@ class GetPostThumbJob extends AbstractJob
 			if (!file_exists($path))
 			{
 				$post = PostModel::getByName($name);
-
-				if ($post->isHidden())
-					Access::assert(new Privilege(Privilege::ListPosts, 'hidden'));
-				Access::assert(new Privilege(Privilege::ListPosts, $post->getSafety()->toString()));
+				$post = $this->postRetriever->retrieve();
 
 				$post->generateThumb($width, $height);
 
@@ -45,16 +50,14 @@ class GetPostThumbJob extends AbstractJob
 	public function getRequiredArguments()
 	{
 		return JobArgs::Conjunction(
-			JobArgs::Alternative(
-				JobArgs::ARG_POST_ENTITY,
-				JobArgs::ARG_POST_NAME),
+			$this->postRetriever->getRequiredArguments(),
 			JobArgs::Optional(JobArgs::ARG_THUMB_WIDTH),
 			JobArgs::Optional(JobArgs::ARG_THUMB_HEIGHT));
 	}
 
 	public function getRequiredPrivileges()
 	{
-		//manually enforced in execute when post is retrieved
+		//privilege check removed to make thumbs faster
 		return false;
 	}
 }

src/Api/Jobs/PostJobs/ListPostsJob.php

@@ -0,0 +1,42 @@
+<?php
+class ListPostsJob extends AbstractJob implements IPagedJob
+{
+	protected $pager;
+
+	public function  __construct()
+	{
+		$this->pager = new JobPager($this);
+		$this->pager->setPageSize(getConfig()->browsing->postsPerPage);
+	}
+
+	public function getPager()
+	{
+		return $this->pager;
+	}
+
+	public function execute()
+	{
+		$pageSize = $this->pager->getPageSize();
+		$page = $this->pager->getPageNumber();
+		$query = $this->getArgument(JobArgs::ARG_QUERY);
+
+		$posts = PostSearchService::getEntities($query, $pageSize, $page);
+		$postCount = PostSearchService::getEntityCount($query);
+
+		PostModel::preloadTags($posts);
+
+		return $this->pager->serialize($posts, $postCount);
+	}
+
+	public function getRequiredArguments()
+	{
+		return JobArgs::Conjunction(
+			$this->pager->getRequiredArguments(),
+			JobArgs::ARG_QUERY);
+	}
+
+	public function getRequiredPrivileges()
+	{
+		return new Privilege(Privilege::ListPosts);
+	}
+}

src/Api/Jobs/PostJobs/ScorePostJob.php

@@ -1,9 +1,16 @@
 <?php
-class ScorePostJob extends AbstractPostJob
+class ScorePostJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$score = intval($this->getArgument(JobArgs::ARG_NEW_POST_SCORE));
 
 		UserModel::updateUserScore(Auth::getCurrentUser(), $post, $score);
@@ -11,16 +18,18 @@ class ScorePostJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_POST_SCORE;
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_POST_SCORE);
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::ScorePost,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 
 	public function isAuthenticationRequired()

src/Api/Jobs/PostJobs/TogglePostFavoriteJob.php

@@ -1,9 +1,16 @@
 <?php
-class TogglePostFavoriteJob extends AbstractPostJob
+class TogglePostFavoriteJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$favorite = boolval($this->getArgument(JobArgs::ARG_NEW_STATE));
 
 		if ($favorite)
@@ -19,16 +26,18 @@ class TogglePostFavoriteJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_STATE;
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_STATE);
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::FavoritePost,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 
 	public function isAuthenticationRequired()

src/Api/Jobs/PostJobs/TogglePostTagJob.php

@@ -1,11 +1,18 @@
 <?php
-class TogglePostTagJob extends AbstractPostJob
+class TogglePostTagJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
 		$tagName = $this->getArgument(JobArgs::ARG_TAG_NAME);
 		$enable = boolval($this->getArgument(JobArgs::ARG_NEW_STATE));
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 
 		$tags = $post->getTags();
 
@@ -50,17 +57,19 @@ class TogglePostTagJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
 		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::Conjunction(
 			JobArgs::ARG_TAG_NAME,
-			Jobargs::ARG_NEW_STATE);
+			Jobargs::ARG_NEW_STATE));
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::EditPostTags,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 }

src/Api/Jobs/PostJobs/TogglePostVisibilityJob.php

@@ -1,9 +1,16 @@
 <?php
-class TogglePostVisibilityJob extends AbstractPostJob
+class TogglePostVisibilityJob extends AbstractJob
 {
+	protected $postRetriever;
+
+	public function __construct()
+	{
+		$this->postRetriever = new PostRetriever($this);
+	}
+
 	public function execute()
 	{
-		$post = $this->post;
+		$post = $this->postRetriever->retrieve();
 		$visible = boolval($this->getArgument(JobArgs::ARG_NEW_STATE));
 
 		$post->setHidden(!$visible);
@@ -19,15 +26,17 @@ class TogglePostVisibilityJob extends AbstractPostJob
 		return $post;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_STATE;
+		return JobArgs::Conjunction(
+			$this->postRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_STATE);
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::HidePost,
-			Access::getIdentity($this->post->getUploader()));
+			Access::getIdentity($this->postRetriever->retrieve()->getUploader()));
 	}
 }

src/Api/Jobs/TagJobs/ListRelatedTagsJob.php

@@ -1,10 +1,23 @@
 <?php
-class ListRelatedTagsJob extends ListTagsJob
+class ListRelatedTagsJob extends AbstractJob implements IPagedJob
 {
+	protected $pager;
+
+	public function __construct()
+	{
+		$this->pager = new JobPager($this);
+		$this->pager->setPageSize(getConfig()->browsing->tagsRelated);
+	}
+
+	public function getPager()
+	{
+		return $this->pager;
+	}
+
 	public function execute()
 	{
-		$pageSize = $this->getPageSize();
-		$page = $this->getArgument(JobArgs::ARG_PAGE_NUMBER);
+		$pageSize = $this->pager->getPageSize();
+		$page = $this->pager->getPageNumber();
 		$tag = $this->getArgument(JobArgs::ARG_TAG_NAME);
 		$otherTags = $this->hasArgument(JobArgs::ARG_TAG_NAMES) ? $this->getArgument(JobArgs::ARG_TAG_NAMES) : [];
 
@@ -13,19 +26,19 @@ class ListRelatedTagsJob extends ListTagsJob
 		$tags = array_filter($tags, function($tag) use ($otherTags) { return !in_array($tag->getName(), $otherTags); });
 		$tags = array_slice($tags, 0, $pageSize);
 
-		return $this->getPager($tags, $tagCount, $page, $pageSize);
-	}
-
-	public function getDefaultPageSize()
-	{
-		return intval(getConfig()->browsing->tagsRelated);
+		return $this->pager->serialize($tags, $tagCount);
 	}
 
 	public function getRequiredArguments()
 	{
 		return JobArgs::Conjunction(
-			parent::getRequiredArguments(),
+			$this->pager->getRequiredArguments(),
 			Jobargs::ARG_TAG_NAME,
 			JobArgs::Optional(JobArgs::ARG_TAG_NAMES));
 	}
+
+	public function getRequiredPrivileges()
+	{
+		return new Privilege(Privilege::ListTags);
+	}
 }

src/Api/Jobs/TagJobs/ListTagsJob.php

@@ -0,0 +1,40 @@
+<?php
+class ListTagsJob extends AbstractJob implements IPagedJob
+{
+	protected $pager;
+
+	public function  __construct()
+	{
+		$this->pager = new JobPager($this);
+		$this->pager->setPageSize(getConfig()->browsing->tagsPerPage);
+	}
+
+	public function getPager()
+	{
+		return $this->pager;
+	}
+
+	public function execute()
+	{
+		$pageSize = $this->pager->getPageSize();
+		$page = $this->pager->getPageNumber();
+		$query = $this->getArgument(JobArgs::ARG_QUERY);
+
+		$tags = TagSearchService::getEntities($query, $pageSize, $page);
+		$tagCount = TagSearchService::getEntityCount($query);
+
+		return $this->pager->serialize($tags, $tagCount);
+	}
+
+	public function getRequiredArguments()
+	{
+		return JobArgs::Conjunction(
+			$this->pager->getRequiredArguments(),
+			JobArgs::ARG_QUERY);
+	}
+
+	public function getRequiredPrivileges()
+	{
+		return new Privilege(Privilege::ListTags);
+	}
+}

src/Api/Jobs/UserJobs/AbstractUserJob.php

@@ -1,30 +0,0 @@
-<?php
-abstract class AbstractUserJob extends AbstractJob
-{
-	protected $user;
-
-	public function prepare()
-	{
-		if ($this->hasArgument(JobArgs::ARG_USER_ENTITY))
-		{
-			$this->user = $this->getArgument(JobArgs::ARG_USER_ENTITY);
-		}
-		else
-		{
-			$userName = $this->getArgument(JobArgs::ARG_USER_NAME);
-			$this->user = UserModel::getByNameOrEmail($userName);
-		}
-	}
-
-	public function getRequiredArguments()
-	{
-		return JobArgs::Conjunction(
-			JobArgs::Alternative(
-				JobArgs::ARG_USER_NAME,
-				JobArgs::ARG_USER_EMAIL,
-				JobArgs::ARG_USER_ENTITY),
-			$this->getRequiredSubArguments());
-	}
-
-	public abstract function getRequiredSubArguments();
-}

src/Api/Jobs/UserJobs/AcceptUserRegistrationJob.php

@@ -1,9 +1,16 @@
 <?php
-class AcceptUserRegistrationJob extends AbstractUserJob
+class AcceptUserRegistrationJob extends AbstractJob
 {
+	protected $userRetriever;
+
+	public function __construct()
+	{
+		$this->userRetriever = new UserRetriever($this);
+	}
+
 	public function execute()
 	{
-		$user = $this->user;
+		$user = $this->userRetriever->getRequiredArguments();
 
 		$user->setStaffConfirmed(true);
 		UserModel::save($user);
@@ -13,9 +20,9 @@ class AcceptUserRegistrationJob extends AbstractUserJob
 			'subject' => TextHelper::reprUser($user)]);
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return null;
+		return $this->userRetriever->getRequiredArguments();
 	}
 
 	public function getRequiredPrivileges()

src/Api/Jobs/UserJobs/ActivateUserEmailJob.php

@@ -1,16 +1,18 @@
 <?php
 class ActivateUserEmailJob extends AbstractJob
 {
+	protected $userRetriever;
+
+	public function __construct()
+	{
+		$this->userRetriever = new UserRetriever($this);
+	}
+
 	public function execute()
 	{
 		if (!$this->hasArgument(JobArgs::ARG_TOKEN))
 		{
-			if ($this->hasArgument(JobArgs::ARG_USER_ENTITY))
-				$user = $this->getArgument(JobArgs::ARG_USER_ENTITY);
-			elseif ($this->hasArgument(JobArgs::ARG_USER_NAME))
-				$user = UserModel::getByName($this->getArgument(JobArgs::ARG_USER_NAME));
-			else
-				$user = UserModel::getByEmail($this->getArgument(JobArgs::ARG_USER_EMAIL));
+			$user = $this->userRetriever->retrieve();
 
 			if (empty($user->getUnconfirmedEmail()))
 			{
@@ -47,10 +49,7 @@ class ActivateUserEmailJob extends AbstractJob
 	{
 		return JobArgs::Alternative(
 			JobArgs::ARG_TOKEN,
-			JobArgs::Alternative(
-				JobArgs::ARG_USER_ENTITY,
-				JobArgs::ARG_USER_EMAIL,
-				JobArgs::ARG_USER_NAME));
+			$this->userRetriever->getRequiredArguments());
 	}
 
 	public static function sendEmail($user)

src/Api/Jobs/UserJobs/DeleteUserJob.php

@@ -1,9 +1,16 @@
 <?php
-class DeleteUserJob extends AbstractUserJob
+class DeleteUserJob extends AbstractJob
 {
+	protected $userRetriever;
+
+	public function __construct()
+	{
+		$this->userRetriever = new UserRetriever($this);
+	}
+
 	public function execute()
 	{
-		$user = $this->user;
+		$user = $this->userRetriever->retrieve();
 
 		$name = $user->getName();
 		UserModel::remove($user);
@@ -13,15 +20,15 @@ class DeleteUserJob extends AbstractUserJob
 			'subject' => TextHelper::reprUser($name)]);
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return null;
+		return $this->userRetriever->getRequiredArguments();
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::DeleteUser,
-			Access::getIdentity($this->user));
+			Access::getIdentity($this->userRetriever->retrieve()));
 	}
 }

src/Api/Jobs/UserJobs/EditUserAccessRankJob.php

@@ -1,9 +1,16 @@
 <?php
-class EditUserAccessRankJob extends AbstractUserJob
+class EditUserAccessRankJob extends AbstractJob
 {
+	protected $userRetriever;
+
+	public function __construct()
+	{
+		$this->userRetriever = new UserRetriever($this);
+	}
+
 	public function execute()
 	{
-		$user = $this->user;
+		$user = $this->userRetriever->retrieve();
 		$newAccessRank = new AccessRank($this->getArgument(JobArgs::ARG_NEW_ACCESS_RANK));
 
 		$oldAccessRank = $user->getAccessRank();
@@ -23,15 +30,17 @@ class EditUserAccessRankJob extends AbstractUserJob
 		return $user;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_ACCESS_RANK;
+		return JobArgs::Conjunction(
+			$this->userRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_ACCESS_RANK);
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::ChangeUserAccessRank,
-			Access::getIdentity($this->user));
+			Access::getIdentity($this->userRetriever->retrieve()));
 	}
 }

src/Api/Jobs/UserJobs/EditUserEmailJob.php

@@ -1,13 +1,20 @@
 <?php
-class EditUserEmailJob extends AbstractUserJob
+class EditUserEmailJob extends AbstractJob
 {
+	protected $userRetriever;
+
+	public function __construct()
+	{
+		$this->userRetriever = new UserRetriever($this);
+	}
+
 	public function execute()
 	{
 		if (getConfig()->registration->needEmailForRegistering)
 			if (!$this->hasArgument(JobArgs::ARG_NEW_EMAIL) or empty($this->getArgument(JobArgs::ARG_NEW_EMAIL)))
 				throw new SimpleException('E-mail address is required - you will be sent confirmation e-mail.');
 
-		$user = $this->user;
+		$user = $this->userRetriever->retrieve();
 		$newEmail = $this->getArgument(JobArgs::ARG_NEW_EMAIL);
 
 		$oldEmail = $user->getConfirmedEmail();
@@ -44,9 +51,11 @@ class EditUserEmailJob extends AbstractUserJob
 		}
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_EMAIL;
+		return JobArgs::Conjunction(
+			$this->userRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_EMAIL);
 	}
 
 	public function getRequiredPrivileges()
@@ -55,6 +64,6 @@ class EditUserEmailJob extends AbstractUserJob
 			$this->getContext() == self::CONTEXT_BATCH_ADD
 				? Privilege::RegisterAccount
 				: Privilege::ChangeUserEmail,
-			Access::getIdentity($this->user));
+			Access::getIdentity($this->userRetriever->retrieve()));
 	}
 }

src/Api/Jobs/UserJobs/EditUserJob.php

@@ -1,10 +1,12 @@
 <?php
-class EditUserJob extends AbstractUserJob
+class EditUserJob extends AbstractJob
 {
+	protected $userRetriever;
 	protected $subJobs;
 
 	public function __construct()
 	{
+		$this->userRetriever = new UserRetriever($this);
 		$this->subJobs =
 		[
 			new EditUserAccessRankJob(),
@@ -34,7 +36,7 @@ class EditUserJob extends AbstractUserJob
 
 	public function execute()
 	{
-		$user = $this->user;
+		$user = $this->userRetriever->retrieve();
 
 		Logger::bufferChanges();
 
@@ -65,9 +67,9 @@ class EditUserJob extends AbstractUserJob
 		return $user;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return null;
+		return $this->userRetriever->getRequiredArguments();
 	}
 
 	public function getRequiredPrivileges()

src/Api/Jobs/UserJobs/EditUserNameJob.php

@@ -1,9 +1,16 @@
 <?php
-class EditUserNameJob extends AbstractUserJob
+class EditUserNameJob extends AbstractJob
 {
+	protected $userRetriever;
+
+	public function __construct()
+	{
+		$this->userRetriever = new UserRetriever($this);
+	}
+
 	public function execute()
 	{
-		$user = $this->user;
+		$user = $this->userRetriever->retrieve();
 		$newName = $this->getArgument(JobArgs::ARG_NEW_USER_NAME);
 
 		$oldName = $user->getName();
@@ -23,9 +30,11 @@ class EditUserNameJob extends AbstractUserJob
 		return $user;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_USER_NAME;
+		return JobArgs::Conjunction(
+			$this->userRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_USER_NAME);
 	}
 
 	public function getRequiredPrivileges()
@@ -34,6 +43,6 @@ class EditUserNameJob extends AbstractUserJob
 			$this->getContext() == self::CONTEXT_BATCH_ADD
 				? Privilege::RegisterAccount
 				: Privilege::ChangeUserName,
-			Access::getIdentity($this->user));
+			Access::getIdentity($this->userRetriever->retrieve()));
 	}
 }

src/Api/Jobs/UserJobs/EditUserPasswordJob.php

@@ -1,9 +1,16 @@
 <?php
-class EditUserPasswordJob extends AbstractUserJob
+class EditUserPasswordJob extends AbstractJob
 {
+	protected $userRetriever;
+
+	public function __construct()
+	{
+		$this->userRetriever = new UserRetriever($this);
+	}
+
 	public function execute()
 	{
-		$user = $this->user;
+		$user = $this->userRetriever->retrieve();
 		$newPassword = $this->getArgument(JobArgs::ARG_NEW_PASSWORD);
 
 		$oldPasswordHash = $user->getPasswordHash();
@@ -22,9 +29,11 @@ class EditUserPasswordJob extends AbstractUserJob
 		return $user;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_PASSWORD;
+		return JobArgs::Conjunction(
+			$this->userRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_PASSWORD);
 	}
 
 	public function getRequiredPrivileges()
@@ -33,6 +42,6 @@ class EditUserPasswordJob extends AbstractUserJob
 			$this->getContext() == self::CONTEXT_BATCH_ADD
 				? Privilege::RegisterAccount
 				: Privilege::ChangeUserPassword,
-			Access::getIdentity($this->user));
+			Access::getIdentity($this->userRetriever->retrieve()));
 	}
 }

src/Api/Jobs/UserJobs/FlagUserJob.php

@@ -1,9 +1,16 @@
 <?php
-class FlagUserJob extends AbstractUserJob
+class FlagUserJob extends AbstractJob
 {
+	protected $userRetriever;
+
+	public function __construct()
+	{
+		$this->userRetriever = new UserRetriever($this);
+	}
+
 	public function execute()
 	{
-		$user = $this->user;
+		$user = $this->userRetriever->retrieve();
 		$key = TextHelper::reprUser($user);
 
 		$flagged = SessionHelper::get('flagged', []);
@@ -19,15 +26,15 @@ class FlagUserJob extends AbstractUserJob
 		return $user;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return null;
+		return $this->userRetriever->getRequiredArguments();
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::FlagUser,
-			Access::getIdentity($this->user));
+			Access::getIdentity($this->userRetriever->retrieve()));
 	}
 }

src/Api/Jobs/UserJobs/GetUserJob.php

@@ -1,20 +1,27 @@
 <?php
-class GetUserJob extends AbstractUserJob
+class GetUserJob extends AbstractJob
 {
-	public function execute()
+	protected $userRetriever;
+
+	public function __construct()
 	{
-		return $this->user;
+		$this->userRetriever = new UserRetriever($this);
 	}
 
-	public function getRequiredSubArguments()
+	public function execute()
 	{
-		return null;
+		return $this->userRetriever->retrieve();
+	}
+
+	public function getRequiredArguments()
+	{
+		return $this->userRetriever->getRequiredArguments();
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::ViewUser,
-			Access::getIdentity($this->user));
+			Access::getIdentity($this->userRetriever->retrieve()));
 	}
 }

src/Api/Jobs/UserJobs/ListUsersJob.php

@@ -0,0 +1,40 @@
+<?php
+class ListUsersJob extends AbstractJob implements IPagedJob
+{
+	protected $pager;
+
+	public function  __construct()
+	{
+		$this->pager = new JobPager($this);
+		$this->pager->setPageSize(getConfig()->browsing->usersPerPage);
+	}
+
+	public function getPager()
+	{
+		return $this->pager;
+	}
+
+	public function execute()
+	{
+		$pageSize = $this->pager->getPageSize();
+		$page = $this->pager->getPageNumber();
+		$filter = $this->getArgument(JobArgs::ARG_QUERY);
+
+		$users = UserSearchService::getEntities($filter, $pageSize, $page);
+		$userCount = UserSearchService::getEntityCount($filter);
+
+		return $this->pager->serialize($users, $userCount);
+	}
+
+	public function getRequiredArguments()
+	{
+		return JobArgs::Conjunction(
+			$this->pager->getRequiredArguments(),
+			JobArgs::ARG_QUERY);
+	}
+
+	public function getRequiredPrivileges()
+	{
+		return new Privilege(Privilege::ListUsers);
+	}
+}

src/Api/Jobs/UserJobs/PasswordResetJob.php

@@ -1,16 +1,18 @@
 <?php
 class PasswordResetJob extends AbstractJob
 {
+	protected $userRetriever;
+
+	public function __construct()
+	{
+		$this->userRetriever = new UserRetriever($this);
+	}
+
 	public function execute()
 	{
 		if (!$this->hasArgument(JobArgs::ARG_TOKEN))
 		{
-			if ($this->hasArgument(JobArgs::ARG_USER_NAME))
-				$user = UserModel::getByNameOrEmail($this->getArgument(JobArgs::ARG_USER_NAME));
-			elseif ($this->hasArgument(JobArgs::ARG_USER_EMAIL))
-				$user = UserModel::getByNameOrEmail($this->getArgument(JobArgs::ARG_USER_EMAIL));
-			else
-				$user = $this->getArgument(JobArgs::ARG_USER_ENTITTY);
+			$user = $this->userRetriever->retrieve();
 
 			if (empty($user->getConfirmedEmail()))
 				throw new SimpleException('This user has no e-mail confirmed; password reset cannot proceed');
@@ -50,9 +52,7 @@ class PasswordResetJob extends AbstractJob
 	public function getRequiredArguments()
 	{
 		return JobArgs::Alternative(
-			JobArgs::ARG_USER_NAME,
-			JobArgs::ARG_USER_EMAIL,
-			JobArgs::ARG_USER_ENTITY,
+			$this->userRetriever->getRequiredArguments(),
 			JobArgs::ARG_TOKEN);
 	}
 

src/Api/Jobs/UserJobs/ToggleUserBanJob.php

@@ -1,9 +1,16 @@
 <?php
-class ToggleUserBanJob extends AbstractUserJob
+class ToggleUserBanJob extends AbstractJob
 {
+	protected $userRetriever;
+
+	public function __construct()
+	{
+		$this->userRetriever = new UserRetriever($this);
+	}
+
 	public function execute()
 	{
-		$user = $this->user;
+		$user = $this->userRetriever->retrieve();
 		$banned = boolval($this->getArgument(JobArgs::ARG_NEW_STATE));
 
 		if ($banned)
@@ -22,15 +29,17 @@ class ToggleUserBanJob extends AbstractUserJob
 		return $user;
 	}
 
-	public function getRequiredSubArguments()
+	public function getRequiredArguments()
 	{
-		return JobArgs::ARG_NEW_STATE;
+		return JobArgs::Conjunction(
+			$this->userRetriever->getRequiredArguments(),
+			JobArgs::ARG_NEW_STATE);
 	}
 
 	public function getRequiredPrivileges()
 	{
 		return new Privilege(
 			Privilege::BanUser,
-			Access::getIdentity($this->user));
+			Access::getIdentity($this->userRetriever->retrieve()));
 	}
 }

tests/Api/ApiArgumentTest.php

@@ -44,9 +44,7 @@ class ApiArgumentTest extends AbstractFullApiTest
 	public function testDeleteCommentJob()
 	{
 		$this->testArguments(new DeleteCommentJob(),
-			JobArgs::Alternative(
-				JobArgs::ARG_COMMENT_ENTITY,
-				JobArgs::ARG_COMMENT_ID));
+			$this->getCommentSelector());
 	}
 
 	public function testDeleteUserJob()
@@ -60,9 +58,7 @@ class ApiArgumentTest extends AbstractFullApiTest
 		$this->testArguments(new EditCommentJob(),
 			JobArgs::Conjunction(
 				JobArgs::ARG_NEW_TEXT,
-				JobArgs::Alternative(
-					JobArgs::ARG_COMMENT_ENTITY,
-					JobArgs::ARG_COMMENT_ID)));
+				$this->getCommentSelector()));
 	}
 
 	public function testEditPostContentJob()
@@ -185,7 +181,7 @@ class ApiArgumentTest extends AbstractFullApiTest
 			JobArgs::Conjunction(
 				JobArgs::ARG_QUERY,
 				JobArgs::ARG_LOG_ID,
-				JobArgs::ARG_PAGE_NUMBER));
+				JobArgs::Optional(JobArgs::ARG_PAGE_NUMBER)));
 	}
 
 	public function testGetPostContentJob()
@@ -218,7 +214,7 @@ class ApiArgumentTest extends AbstractFullApiTest
 	public function testListCommentsJob()
 	{
 		$this->testArguments(new ListCommentsJob(),
-				JobArgs::ARG_PAGE_NUMBER);
+			JobArgs::Optional(JobArgs::ARG_PAGE_NUMBER));
 	}
 
 	public function testListLogsJob()
@@ -232,7 +228,7 @@ class ApiArgumentTest extends AbstractFullApiTest
 		$this->testArguments(new ListPostsJob(),
 			JobArgs::Conjunction(
 				JobArgs::ARG_QUERY,
-				JobArgs::ARG_PAGE_NUMBER));
+				JobArgs::Optional(JobArgs::ARG_PAGE_NUMBER)));
 	}
 
 	public function testListRelatedTagsJob()
@@ -241,8 +237,7 @@ class ApiArgumentTest extends AbstractFullApiTest
 			JobArgs::Conjunction(
 				JobArgs::Optional(JobArgs::ARG_TAG_NAMES),
 				JobArgs::ARG_TAG_NAME,
-				JobArgs::ARG_QUERY,
-				JobArgs::ARG_PAGE_NUMBER));
+				JobArgs::Optional(JobArgs::ARG_PAGE_NUMBER)));
 	}
 
 	public function testListTagsJob()
@@ -250,7 +245,7 @@ class ApiArgumentTest extends AbstractFullApiTest
 		$this->testArguments(new ListTagsJob(),
 			JobArgs::Conjunction(
 				JobArgs::ARG_QUERY,
-				JobArgs::ARG_PAGE_NUMBER));
+				JobArgs::Optional(JobArgs::ARG_PAGE_NUMBER)));
 	}
 
 	public function testListUsersJob()
@@ -258,7 +253,7 @@ class ApiArgumentTest extends AbstractFullApiTest
 		$this->testArguments(new ListUsersJob(),
 			JobArgs::Conjunction(
 				JobArgs::ARG_QUERY,
-				JobArgs::ARG_PAGE_NUMBER));
+				JobArgs::Optional(JobArgs::ARG_PAGE_NUMBER)));
 	}
 
 	public function testMergeTagsJob()
@@ -290,8 +285,8 @@ class ApiArgumentTest extends AbstractFullApiTest
 		$this->testArguments(new PreviewCommentJob(),
 			JobArgs::Conjunction(
 				JobArgs::Alternative(
-					JobArgs::ARG_POST_ID,
-					JobArgs::ARG_COMMENT_ID),
+					$this->getPostSelector(),
+					$this->getCommentSelector()),
 				JobArgs::ARG_NEW_TEXT));
 	}
 
@@ -357,6 +352,13 @@ class ApiArgumentTest extends AbstractFullApiTest
 			JobArgs::ARG_POST_ENTITY);
 	}
 
+	protected function getCommentSelector()
+	{
+		return JobArgs::Alternative(
+			JobArgs::ARG_COMMENT_ENTITY,
+			JobArgs::ARG_COMMENT_ID);
+	}
+
 	protected function getUserSelector()
 	{
 		return JobArgs::Alternative(