77 lines
2.8 KiB
TypeScript
77 lines
2.8 KiB
TypeScript
|
/*************************************************************
|
||
|
|
*
|
||
|
|
* Copyright (c) 2021-2022 The MathJax Consortium
|
||
|
|
*
|
||
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
* you may not use this file except in compliance with the License.
|
||
|
|
* You may obtain a copy of the License at
|
||
|
|
*
|
||
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
*
|
||
|
|
* Unless required by applicable law or agreed to in writing, software
|
||
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
* See the License for the specific language governing permissions and
|
||
|
|
* limitations under the License.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @fileoverview Auxiliary function for elementary MathML3 support (experimental)
|
||
|
|
* using David Carlisle's XLST transform.
|
||
|
|
*
|
||
|
|
* @author dpvc@mathjax.org (Davide Cervone)
|
||
|
|
*/
|
||
|
|
|
||
|
|
import {MathDocument} from '../../../core/MathDocument.js';
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Create the transform function that uses Saxon-js to perform the
|
||
|
|
* xslt transformation.
|
||
|
|
*
|
||
|
|
* @template N The HTMLElement node class
|
||
|
|
* @template T The Text node class
|
||
|
|
* @template D The Document class
|
||
|
|
*
|
||
|
|
* @return {(node: N, doc: MathDocument<N,T,D>) => N)} The transformation function
|
||
|
|
*/
|
||
|
|
export function createTransform<N, T, D>(): (node: N, doc: MathDocument<N, T, D>) => N {
|
||
|
|
/* tslint:disable-next-line:no-eval */
|
||
|
|
const nodeRequire = eval('require'); // get the actual require from node.
|
||
|
|
/* tslint:disable-next-line:no-eval */
|
||
|
|
const dirname = eval('__dirname'); // get the actual __dirname
|
||
|
|
try {
|
||
|
|
nodeRequire.resolve('saxon-js'); // check if saxon-js is installed.
|
||
|
|
} catch (err) {
|
||
|
|
throw Error('Saxon-js not found. Run the command:\n npm install saxon-js\nand try again.');
|
||
|
|
}
|
||
|
|
const Saxon = nodeRequire('saxon-js'); // dynamically load Saxon-JS.
|
||
|
|
const path = nodeRequire('path'); // use the real version from node.
|
||
|
|
const fs = nodeRequire('fs'); // use the real version from node.
|
||
|
|
const xsltFile = path.resolve(dirname, 'mml3.sef.json'); // load the preprocessed stylesheet.
|
||
|
|
const xslt = JSON.parse(fs.readFileSync(xsltFile)); // and parse it.
|
||
|
|
return (node: N, doc: MathDocument<N, T, D>) => {
|
||
|
|
const adaptor = doc.adaptor;
|
||
|
|
let mml = adaptor.outerHTML(node);
|
||
|
|
//
|
||
|
|
// Make sure the namespace is present
|
||
|
|
//
|
||
|
|
if (!mml.match(/ xmlns[=:]/)) {
|
||
|
|
mml = mml.replace(/<(?:(\w+)(:))?math/, '<$1$2math xmlns$2$1="http://www.w3.org/1998/Math/MathML"');
|
||
|
|
}
|
||
|
|
//
|
||
|
|
// Try to run the transform, and if it fails, return the original MathML
|
||
|
|
//
|
||
|
|
let result;
|
||
|
|
try {
|
||
|
|
result = adaptor.firstChild(adaptor.body(adaptor.parse(Saxon.transform({
|
||
|
|
stylesheetInternal: xslt,
|
||
|
|
sourceText: mml,
|
||
|
|
destination: 'serialized'
|
||
|
|
}).principalResult))) as N;
|
||
|
|
} catch (err) {
|
||
|
|
result = node;
|
||
|
|
}
|
||
|
|
return result;
|
||
|
|
};
|
||
|
|
}
|