From f1445b9c24b286a9f74a2fead655ab5c169bc74b Mon Sep 17 00:00:00 2001
From: rr- <rr-@sakuya.pl>
Date: Sat, 22 Oct 2016 10:03:38 +0200
Subject: [PATCH] client/posts: add post merging

---
 client/css/post-detail-view.styl              |  33 +++++
 .../{post-view.styl => post-main-view.styl}   |   0
 client/html/post_detail.tpl                   |  12 ++
 client/html/post_edit_sidebar.tpl             |   5 +-
 client/html/{post.tpl => post_main.tpl}       |   0
 client/html/post_merge.tpl                    |  23 ++++
 client/html/post_merge_side.tpl               |  48 +++++++
 client/js/controllers/base_post_controller.js |  20 +++
 .../js/controllers/post_detail_controller.js  |  86 ++++++++++++
 ..._controller.js => post_main_controller.js} |  37 +++--
 .../js/controls/post_edit_sidebar_control.js  |  19 +++
 client/js/main.js                             |   3 +-
 client/js/models/post.js                      |  25 ++++
 client/js/views/post_detail_view.js           |  80 +++++++++++
 .../views/{post_view.js => post_main_view.js} |   6 +-
 client/js/views/post_merge_view.js            | 129 ++++++++++++++++++
 16 files changed, 502 insertions(+), 24 deletions(-)
 create mode 100644 client/css/post-detail-view.styl
 rename client/css/{post-view.styl => post-main-view.styl} (100%)
 create mode 100644 client/html/post_detail.tpl
 rename client/html/{post.tpl => post_main.tpl} (100%)
 create mode 100644 client/html/post_merge.tpl
 create mode 100644 client/html/post_merge_side.tpl
 create mode 100644 client/js/controllers/base_post_controller.js
 create mode 100644 client/js/controllers/post_detail_controller.js
 rename client/js/controllers/{post_controller.js => post_main_controller.js} (91%)
 create mode 100644 client/js/views/post_detail_view.js
 rename client/js/views/{post_view.js => post_main_view.js} (97%)
 create mode 100644 client/js/views/post_merge_view.js

diff --git a/client/css/post-detail-view.styl b/client/css/post-detail-view.styl
new file mode 100644
index 00000000..32e74973
--- /dev/null
+++ b/client/css/post-detail-view.styl
@@ -0,0 +1,33 @@
+#post
+    width: 100%
+    max-width: 40em
+    h1
+        margin-top: 0
+    form
+        width: 100%
+    .buttons i
+        margin-right: 0.5em
+    .post-merge
+        .left-post-container
+            width: 47%
+            float: left
+        .right-post-container
+            width: 47%
+            float: right
+        input[type=text]
+            width: 8em
+            margin-top: -2px
+        .post-mirror
+            margin-bottom: 1em
+            &:after
+                display: block
+                height: 1px
+                content: ' '
+                clear: both
+        .post-thumbnail .thumbnail
+            width: 100%
+            height: 9em
+        .target-post .thumbnail
+            margin-right: 0.35em
+        .target-post, .target-post-content
+            margin: 1em 0
diff --git a/client/css/post-view.styl b/client/css/post-main-view.styl
similarity index 100%
rename from client/css/post-view.styl
rename to client/css/post-main-view.styl
diff --git a/client/html/post_detail.tpl b/client/html/post_detail.tpl
new file mode 100644
index 00000000..5e04ab22
--- /dev/null
+++ b/client/html/post_detail.tpl
@@ -0,0 +1,12 @@
+<div class='content-wrapper' id='post'>
+    <h1>Post #<%- ctx.post.id %></h1>
+    <nav class='buttons'><!--
+        --><ul><!--
+            --><li><a href='/post/<%- ctx.post.id %>'><i class='fa fa-reply'></i> Main view</a></li><!--
+            --><% if (ctx.canMerge) { %><!--
+                --><li data-name='merge'><a href='/post/<%- ctx.post.id %>/merge'>Merge with&hellip;</a></li><!--
+            --><% } %><!--
+        --></ul><!--
+    --></nav>
+    <div class='post-content-holder'></div>
+</div>
diff --git a/client/html/post_edit_sidebar.tpl b/client/html/post_edit_sidebar.tpl
index 9b088917..d36a0e4e 100644
--- a/client/html/post_edit_sidebar.tpl
+++ b/client/html/post_edit_sidebar.tpl
@@ -84,12 +84,15 @@
             </section>
         <% } %>
 
-        <% if (ctx.canFeaturePosts || ctx.canDeletePosts) { %>
+        <% if (ctx.canFeaturePosts || ctx.canDeletePosts || ctx.canMergePosts) { %>
             <section class='management'>
                 <ul>
                     <% if (ctx.canFeaturePosts) { %>
                         <li><a href class='feature'>Feature this post on main page</a></li>
                     <% } %>
+                    <% if (ctx.canMergePosts) { %>
+                        <li><a href class='merge'>Merge this post with another</a></li>
+                    <% } %>
                     <% if (ctx.canDeletePosts) { %>
                         <li><a href class='delete'>Delete this post</a></li>
                     <% } %>
diff --git a/client/html/post.tpl b/client/html/post_main.tpl
similarity index 100%
rename from client/html/post.tpl
rename to client/html/post_main.tpl
diff --git a/client/html/post_merge.tpl b/client/html/post_merge.tpl
new file mode 100644
index 00000000..59b3f495
--- /dev/null
+++ b/client/html/post_merge.tpl
@@ -0,0 +1,23 @@
+<div class='post-merge'>
+    <form>
+        <ul>
+            <li class='post-mirror'>
+                <div class='left-post-container'></div>
+                <div class='right-post-container'></div>
+            </li>
+
+            <li>
+                <p>Tags, relations, scores, favorites and comments will be
+                merged. All other properties need to be handled manually.</p>
+
+                <%= ctx.makeCheckbox({required: true, text: 'I confirm that I want to merge these posts.'}) %>
+            </li>
+        </ul>
+
+        <div class='messages'></div>
+
+        <div class='buttons'>
+            <input type='submit' value='Merge posts'/>
+        </div>
+    </form>
+</div>
diff --git a/client/html/post_merge_side.tpl b/client/html/post_merge_side.tpl
new file mode 100644
index 00000000..60cc080b
--- /dev/null
+++ b/client/html/post_merge_side.tpl
@@ -0,0 +1,48 @@
+<% if (ctx.editable) { %>
+    <p>Post # <input type='text' pattern='^[0-9]+$' value='<%- ctx.post ? ctx.post.id : '' %>'/></p>
+<% } else { %>
+    <p>Post # <input type='text' pattern='^[0-9]+$' value='<%- ctx.post ? ctx.post.id : '' %>' readonly/></p>
+<% } %>
+
+<% if (ctx.post) { %>
+    <div class='post-thumbnail'>
+        <a rel='external' href='<%- ctx.post.contentUrl %>'>
+            <%= ctx.makeThumbnail(ctx.post.thumbnailUrl) %>
+        </a>
+    </div>
+    <div class='target-post'>
+        <%= ctx.makeRadio({
+            required: true,
+            text: 'Merge to this post<br/><small>' +
+                ctx.makeUserLink(ctx.post.user) +
+                ', ' +
+                ctx.makeRelativeTime(ctx.post.creationTime) +
+                '</small>',
+            name: 'target-post',
+            value: ctx.name,
+        }) %>
+    </div>
+    <div class='target-post-content'>
+        <%= ctx.makeRadio({
+            required: true,
+            text: 'Use this file<br/><small>' +
+                ctx.makeFileSize(ctx.post.fileSize) + ' ' +
+                {
+                    'image/gif': 'GIF',
+                    'image/jpeg': 'JPEG',
+                    'image/png': 'PNG',
+                    'video/webm': 'WEBM',
+                    'application/x-shockwave-flash': 'SWF',
+                }[ctx.post.mimeType] +
+                ' (' +
+                (ctx.post.canvasWidth ?
+                    `${ctx.post.canvasWidth}x${ctx.post.canvasHeight}` :
+                    '?') +
+                ')</small>',
+            name: 'target-post-content',
+            value: ctx.name,
+        }) %>
+        <p>
+        </p>
+    </div>
+<% } %>
diff --git a/client/js/controllers/base_post_controller.js b/client/js/controllers/base_post_controller.js
new file mode 100644
index 00000000..b86aea72
--- /dev/null
+++ b/client/js/controllers/base_post_controller.js
@@ -0,0 +1,20 @@
+'use strict';
+
+const api = require('../api.js');
+const topNavigation = require('../models/top_navigation.js');
+const EmptyView = require('../views/empty_view.js');
+
+class BasePostController {
+    constructor(ctx) {
+        if (!api.hasPrivilege('posts:view')) {
+            this._view = new EmptyView();
+            this._view.showError('You don\'t have privileges to view posts.');
+            return;
+        }
+
+        topNavigation.activate('posts');
+        topNavigation.setTitle('Post #' + ctx.parameters.id.toString());
+    }
+}
+
+module.exports = BasePostController;
diff --git a/client/js/controllers/post_detail_controller.js b/client/js/controllers/post_detail_controller.js
new file mode 100644
index 00000000..cdff681c
--- /dev/null
+++ b/client/js/controllers/post_detail_controller.js
@@ -0,0 +1,86 @@
+'use strict';
+
+const router = require('../router.js');
+const api = require('../api.js');
+const misc = require('../util/misc.js');
+const settings = require('../models/settings.js');
+const Comment = require('../models/comment.js');
+const Post = require('../models/post.js');
+const PostList = require('../models/post_list.js');
+const PostDetailView = require('../views/post_detail_view.js');
+const BasePostController = require('./base_post_controller.js');
+const EmptyView = require('../views/empty_view.js');
+
+class PostDetailController extends BasePostController {
+    constructor(ctx, section) {
+        super(ctx);
+
+        Post.get(ctx.parameters.id).then(post => {
+            this._id = ctx.parameters.id;
+            post.addEventListener('change', e => this._evtSaved(e, section));
+
+            this._view = new PostDetailView({
+                post: post,
+                section: section,
+                canMerge: api.hasPrivilege('posts:merge'),
+            });
+
+            this._view.addEventListener('select', e => this._evtSelect(e));
+            this._view.addEventListener('merge', e => this._evtMerge(e));
+        }, errorMessage => {
+            this._view = new EmptyView();
+            this._view.showError(errorMessage);
+        });
+    }
+
+    showSuccess(message) {
+        this._view.showSuccess(message);
+    }
+
+    _evtSelect(e) {
+        this._view.clearMessages();
+        this._view.disableForm();
+        Post.get(e.detail.postId).then(post => {
+            this._view.selectPost(post);
+            this._view.enableForm();
+        }, errorMessage => {
+            this._view.showError(errorMessage);
+            this._view.enableForm();
+        });
+    }
+
+    _evtSaved(e, section) {
+        misc.disableExitConfirmation();
+        if (this._id !== e.detail.post.id) {
+            router.replace(
+                '/post/' + e.detail.post.id + '/' + section, null, false);
+        }
+    }
+
+    _evtMerge(e) {
+        this._view.clearMessages();
+        this._view.disableForm();
+        e.detail.post.merge(e.detail.targetPost.id, e.detail.useOldContent)
+            .then(() => {
+                this._view = new PostDetailView({
+                    post: e.detail.targetPost,
+                    section: 'merge',
+                    canMerge: api.hasPrivilege('posts:merge'),
+                });
+                this._view.showSuccess('Post merged.');
+                router.replace(
+                    '/post/' + e.detail.targetPost.id + '/merge', null, false);
+            }, errorMessage => {
+                this._view.showError(errorMessage);
+                this._view.enableForm();
+            });
+    }
+}
+
+module.exports = router => {
+    router.enter(
+        '/post/:id/merge',
+        (ctx, next) => {
+            ctx.controller = new PostDetailController(ctx, 'merge');
+        });
+};
diff --git a/client/js/controllers/post_controller.js b/client/js/controllers/post_main_controller.js
similarity index 91%
rename from client/js/controllers/post_controller.js
rename to client/js/controllers/post_main_controller.js
index 384643af..561ecb46 100644
--- a/client/js/controllers/post_controller.js
+++ b/client/js/controllers/post_main_controller.js
@@ -7,26 +7,19 @@ const settings = require('../models/settings.js');
 const Comment = require('../models/comment.js');
 const Post = require('../models/post.js');
 const PostList = require('../models/post_list.js');
-const topNavigation = require('../models/top_navigation.js');
-const PostView = require('../views/post_view.js');
+const PostMainView = require('../views/post_main_view.js');
+const BasePostController = require('./base_post_controller.js');
 const EmptyView = require('../views/empty_view.js');
 
-class PostController {
-    constructor(id, editMode, ctx) {
-        if (!api.hasPrivilege('posts:view')) {
-            this._view = new EmptyView();
-            this._view.showError('You don\'t have privileges to view posts.');
-            return;
-        }
-
-        topNavigation.activate('posts');
-        topNavigation.setTitle('Post #' + id.toString());
+class PostMainController extends BasePostController {
+    constructor(ctx, editMode) {
+        super(ctx);
 
         let parameters = ctx.parameters;
         Promise.all([
-                Post.get(id),
+                Post.get(ctx.parameters.id),
                 PostList.getAround(
-                    id, this._decorateSearchQuery(
+                    ctx.parameters.id, this._decorateSearchQuery(
                         parameters ? parameters.query : '')),
         ]).then(responses => {
             const [post, aroundResponse] = responses;
@@ -36,13 +29,13 @@ class PostController {
             if (parameters.query) {
                 ctx.state.parameters = parameters;
                 const url = editMode ?
-                    '/post/' + id + '/edit' :
-                    '/post/' + id;
+                    '/post/' + ctx.parameters.id + '/edit' :
+                    '/post/' + ctx.parameters.id;
                 router.replace(url, ctx.state, false);
             }
 
             this._post = post;
-            this._view = new PostView({
+            this._view = new PostMainView({
                 post: post,
                 editMode: editMode,
                 prevPostId: aroundResponse.prev ? aroundResponse.prev.id : null,
@@ -72,6 +65,8 @@ class PostController {
                     'feature', e => this._evtFeaturePost(e));
                 this._view.sidebarControl.addEventListener(
                     'delete', e => this._evtDeletePost(e));
+                this._view.sidebarControl.addEventListener(
+                    'merge', e => this._evtMergePost(e));
             }
 
             if (this._view.commentFormControl) {
@@ -128,6 +123,10 @@ class PostController {
             });
     }
 
+    _evtMergePost(e) {
+        router.show('/post/' + e.detail.post.id + '/merge');
+    }
+
     _evtDeletePost(e) {
         this._view.sidebarControl.disableForm();
         this._view.sidebarControl.clearMessages();
@@ -262,7 +261,7 @@ module.exports = router => {
             if (ctx.state.parameters) {
                 Object.assign(ctx.parameters, ctx.state.parameters);
             }
-            ctx.controller = new PostController(ctx.parameters.id, true, ctx);
+            ctx.controller = new PostMainController(ctx, true);
         });
     router.enter(
         '/post/:id/:parameters(.*)?',
@@ -272,6 +271,6 @@ module.exports = router => {
             if (ctx.state.parameters) {
                 Object.assign(ctx.parameters, ctx.state.parameters);
             }
-            ctx.controller = new PostController(ctx.parameters.id, false, ctx);
+            ctx.controller = new PostMainController(ctx, false);
         });
 };
diff --git a/client/js/controls/post_edit_sidebar_control.js b/client/js/controls/post_edit_sidebar_control.js
index 2dc36299..49576a12 100644
--- a/client/js/controls/post_edit_sidebar_control.js
+++ b/client/js/controls/post_edit_sidebar_control.js
@@ -36,6 +36,7 @@ class PostEditSidebarControl extends events.EventTarget {
             canCreateAnonymousPosts: api.hasPrivilege('posts:create:anonymous'),
             canDeletePosts: api.hasPrivilege('posts:delete'),
             canFeaturePosts: api.hasPrivilege('posts:feature'),
+            canMergePosts: api.hasPrivilege('posts:merge'),
         }));
 
         new ExpanderControl(
@@ -108,6 +109,11 @@ class PostEditSidebarControl extends events.EventTarget {
                 'click', e => this._evtFeatureClick(e));
         }
 
+        if (this._mergeLinkNode) {
+            this._mergeLinkNode.addEventListener(
+                'click', e => this._evtMergeClick(e));
+        }
+
         if (this._deleteLinkNode) {
             this._deleteLinkNode.addEventListener(
                 'click', e => this._evtDeleteClick(e));
@@ -186,6 +192,15 @@ class PostEditSidebarControl extends events.EventTarget {
         }
     }
 
+    _evtMergeClick(e) {
+        e.preventDefault();
+        this.dispatchEvent(new CustomEvent('merge', {
+            detail: {
+                post: this._post,
+            },
+        }));
+    }
+
     _evtDeleteClick(e) {
         e.preventDefault();
         if (confirm('Are you sure you want to delete this post?')) {
@@ -314,6 +329,10 @@ class PostEditSidebarControl extends events.EventTarget {
         return this._formNode.querySelector('.management .feature');
     }
 
+    get _mergeLinkNode() {
+        return this._formNode.querySelector('.management .merge');
+    }
+
     get _deleteLinkNode() {
         return this._formNode.querySelector('.management .delete');
     }
diff --git a/client/js/main.js b/client/js/main.js
index 25b64695..0f324b6f 100644
--- a/client/js/main.js
+++ b/client/js/main.js
@@ -34,7 +34,8 @@ controllers.push(require('./controllers/auth_controller.js'));
 controllers.push(require('./controllers/password_reset_controller.js'));
 controllers.push(require('./controllers/comments_controller.js'));
 controllers.push(require('./controllers/snapshots_controller.js'));
-controllers.push(require('./controllers/post_controller.js'));
+controllers.push(require('./controllers/post_detail_controller.js'));
+controllers.push(require('./controllers/post_main_controller.js'));
 controllers.push(require('./controllers/post_list_controller.js'));
 controllers.push(require('./controllers/post_upload_controller.js'));
 controllers.push(require('./controllers/tag_controller.js'));
diff --git a/client/js/models/post.js b/client/js/models/post.js
index f5f8f00e..56a9450a 100644
--- a/client/js/models/post.js
+++ b/client/js/models/post.js
@@ -190,6 +190,31 @@ class Post extends events.EventTarget {
             });
     }
 
+    merge(targetId, useOldContent) {
+        return api.get('/post/' + encodeURIComponent(targetId))
+            .then(response => {
+                return api.post('/post-merge/', {
+                    removeVersion: this._version,
+                    remove: this._id,
+                    mergeToVersion: response.version,
+                    mergeTo: targetId,
+                    replaceContent: useOldContent,
+                });
+            }, response => {
+                return Promise.reject(response);
+            }).then(response => {
+                this._updateFromResponse(response);
+                this.dispatchEvent(new CustomEvent('change', {
+                    detail: {
+                        post: this,
+                    },
+                }));
+                return Promise.resolve();
+            }, response => {
+                return Promise.reject(response.description);
+            });
+    }
+
     setScore(score) {
         return api.put('/post/' + this._id + '/score', {score: score})
             .then(response => {
diff --git a/client/js/views/post_detail_view.js b/client/js/views/post_detail_view.js
new file mode 100644
index 00000000..4c19059f
--- /dev/null
+++ b/client/js/views/post_detail_view.js
@@ -0,0 +1,80 @@
+'use strict';
+
+const events = require('../events.js');
+const views = require('../util/views.js');
+const PostMergeView = require('./post_merge_view.js');
+const EmptyView = require('../views/empty_view.js');
+
+const template = views.getTemplate('post-detail');
+
+class PostDetailView extends events.EventTarget {
+    constructor(ctx) {
+        super();
+
+        this._ctx = ctx;
+        ctx.post.addEventListener('change', e => this._evtChange(e));
+        ctx.section = ctx.section || 'summary';
+
+        this._hostNode = document.getElementById('content-holder');
+        this._install();
+    }
+
+    _install() {
+        const ctx = this._ctx;
+        views.replaceContent(this._hostNode, template(ctx));
+
+        for (let item of this._hostNode.querySelectorAll('[data-name]')) {
+            item.classList.toggle(
+                'active', item.getAttribute('data-name') === ctx.section);
+        }
+
+        ctx.hostNode = this._hostNode.querySelector('.post-content-holder');
+        if (ctx.section === 'merge') {
+            if (!this._ctx.canMerge) {
+                this._view = new EmptyView();
+                this._view.showError(
+                    'You don\'t have privileges to merge posts.');
+            } else {
+                this._view = new PostMergeView(ctx);
+                events.proxyEvent(this._view, this, 'select');
+                events.proxyEvent(this._view, this, 'submit', 'merge');
+            }
+
+        } else {
+            // this._view = new PostSummaryView(ctx);
+        }
+
+        views.syncScrollPosition();
+    }
+
+    clearMessages() {
+        this._view.clearMessages();
+    }
+
+    enableForm() {
+        this._view.enableForm();
+    }
+
+    disableForm() {
+        this._view.disableForm();
+    }
+
+    showSuccess(message) {
+        this._view.showSuccess(message);
+    }
+
+    showError(message) {
+        this._view.showError(message);
+    }
+
+    selectPost(post) {
+        this._view.selectPost(post);
+    }
+
+    _evtChange(e) {
+        this._ctx.post = e.detail.post;
+        this._install(this._ctx);
+    }
+}
+
+module.exports = PostDetailView;
diff --git a/client/js/views/post_view.js b/client/js/views/post_main_view.js
similarity index 97%
rename from client/js/views/post_view.js
rename to client/js/views/post_main_view.js
index 256eb2d1..446297d8 100644
--- a/client/js/views/post_view.js
+++ b/client/js/views/post_main_view.js
@@ -13,9 +13,9 @@ const PostEditSidebarControl =
 const CommentListControl = require('../controls/comment_list_control.js');
 const CommentFormControl = require('../controls/comment_form_control.js');
 
-const template = views.getTemplate('post');
+const template = views.getTemplate('post-main');
 
-class PostView {
+class PostMainView {
     constructor(ctx) {
         this._hostNode = document.getElementById('content-holder');
 
@@ -118,4 +118,4 @@ class PostView {
     }
 }
 
-module.exports = PostView;
+module.exports = PostMainView;
diff --git a/client/js/views/post_merge_view.js b/client/js/views/post_merge_view.js
new file mode 100644
index 00000000..fb17527a
--- /dev/null
+++ b/client/js/views/post_merge_view.js
@@ -0,0 +1,129 @@
+'use strict';
+
+const config = require('../config.js');
+const events = require('../events.js');
+const views = require('../util/views.js');
+
+const KEY_RETURN = 13;
+const template = views.getTemplate('post-merge');
+const sideTemplate = views.getTemplate('post-merge-side');
+
+class PostMergeView extends events.EventTarget {
+    constructor(ctx) {
+        super();
+
+        this._ctx = ctx;
+        this._post = ctx.post;
+        this._hostNode = ctx.hostNode;
+
+        this._leftPost = ctx.post;
+        this._rightPost = null;
+        views.replaceContent(this._hostNode, template(this._ctx));
+        views.decorateValidator(this._formNode);
+
+        this._refreshLeftSide();
+        this._refreshRightSide();
+
+        this._formNode.addEventListener('submit', e => this._evtSubmit(e));
+    }
+
+    clearMessages() {
+        views.clearMessages(this._hostNode);
+    }
+
+    enableForm() {
+        views.enableForm(this._formNode);
+    }
+
+    disableForm() {
+        views.disableForm(this._formNode);
+    }
+
+    showSuccess(message) {
+        views.showSuccess(this._hostNode, message);
+    }
+
+    showError(message) {
+        views.showError(this._hostNode, message);
+    }
+
+    selectPost(post) {
+        this._rightPost = post;
+        this._refreshRightSide();
+    }
+
+    _refreshLeftSide() {
+        views.replaceContent(
+            this._leftSideNode,
+            sideTemplate(Object.assign({}, this._ctx, {
+                post: this._leftPost,
+                name: 'left',
+                editable: false})));
+    }
+
+    _refreshRightSide() {
+        views.replaceContent(
+            this._rightSideNode,
+            sideTemplate(Object.assign({}, this._ctx, {
+                post: this._rightPost,
+                name: 'right',
+                editable: true})));
+
+        if (this._targetPostFieldNode) {
+            this._targetPostFieldNode.addEventListener(
+                'keydown', e => this._evtTargetPostFieldKeyDown(e));
+        }
+    }
+
+    _evtSubmit(e) {
+        e.preventDefault();
+        const checkedTargetPost = this._formNode.querySelector(
+            '.target-post :checked').value;
+        const checkedTargetPostContent = this._formNode.querySelector(
+            '.target-post-content :checked').value;
+        this.dispatchEvent(new CustomEvent('submit', {
+            detail: {
+                post: checkedTargetPost == 'left' ?
+                    this._rightPost :
+                    this._leftPost,
+                targetPost: checkedTargetPost == 'left' ?
+                    this._leftPost :
+                    this._rightPost,
+                useOldContent: checkedTargetPostContent !== checkedTargetPost,
+            },
+        }));
+    }
+
+    _evtTargetPostFieldKeyDown(e) {
+        const key = e.which;
+        if (key !== KEY_RETURN) {
+            return;
+        }
+        e.target.blur();
+        e.preventDefault();
+        this.dispatchEvent(new CustomEvent('select', {
+            detail: {
+                postId: this._targetPostFieldNode.value,
+            },
+        }));
+    }
+
+    get _formNode() {
+        return this._hostNode.querySelector('form');
+    }
+
+    get _leftSideNode() {
+        return this._hostNode.querySelector('.left-post-container');
+    }
+
+    get _rightSideNode() {
+        return this._hostNode.querySelector('.right-post-container');
+    }
+
+    get _targetPostFieldNode() {
+        return this._formNode.querySelector(
+            '.post-mirror input:not([readonly])[type=text]');
+    }
+}
+
+module.exports = PostMergeView;