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tell markdown parser to ignore properly-formatted math tags

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This commit is contained in:
Aleks Kissinger 2020-10-12 21:01:11 +01:00
parent bdd332c8b5
commit f0c4473107
1 changed files with 41 additions and 10 deletions
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51
src/Markdown.js
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@ -23,19 +23,47 @@ const ALLOWED_HTML_TAGS = ['sub', 'sup', 'del', 'u'];
// These types of node are definitely text
const TEXT_NODES = ['text', 'softbreak', 'linebreak', 'paragraph', 'document'];
function is_math_node(node) {
return node != null &&
node.literal != null &&
node.literal.match(/^<((div|span) data-mx-maths="[^"]*"|\/(div|span))>$/) != null;
// prevent renderer from interpreting contents of AST node
function freeze_node(walker, node) {
const newNode = new commonmark.Node('custom_inline', node.sourcepos);
newNode.onEnter = node.literal;
node.insertAfter(newNode);
node.unlink();
walker.resumeAt(newNode.next, true);
}
// prevent renderer from interpreting contents of latex math tags
function freeze_math(parsed) {
const walker = parsed.walker();
let ev;
let inMath = false;
while ( (ev = walker.next()) ) {
const node = ev.node;
if (ev.entering) {
if (!inMath) {
// entering a math tag
if (node.literal != null && node.literal.match('^<(div|span) data-mx-maths="[^"]*">$') != null) {
inMath = true;
freeze_node(walker, node);
}
} else {
// math tags should only contain a single code block, with URL-escaped latex as fallback output
if (node.literal != null && node.literal.match('^(<code>|</code>|[^<>]*)$')) {
freeze_node(walker, node);
// leave when span or div is closed
} else if (node.literal == '</span>' || node.literal == '</div>') {
inMath = false;
freeze_node(walker, node);
// this case only happens if we have improperly formatted math tags, so bail
} else {
inMath = false;
}
}
}
}
}
function is_allowed_html_tag(node) {
if (SettingsStore.getValue("feature_latex_maths") &&
(is_math_node(node) ||
(node.literal.match(/^<\/?code>$/) && is_math_node(node.parent)))) {
return true;
}
// Regex won't work for tags with attrs, but we only
// allow <del> anyway.
const matches = /^<\/?(.*)>$/.exec(node.literal);
@ -173,6 +201,9 @@ export default class Markdown {
*/
};
// prevent strange behaviour when mixing latex math and markdown
freeze_math(this.parsed);
return renderer.render(this.parsed);
}