Files
voidraft/frontend/src/common/markdown-it/plugins/markdown-it-footnote/index.ts

390 lines
13 KiB
TypeScript

import MarkdownIt, {Renderer, StateBlock, StateCore, StateInline, Token} from 'markdown-it';
/**
* 脚注元数据接口
*/
interface FootnoteMeta {
id: number;
subId: number;
label: string;
}
/**
* 脚注列表项接口
*/
interface FootnoteItem {
label?: string;
content?: string;
tokens?: Token[];
count: number;
}
/**
* 环境接口
*/
interface FootnoteEnv {
footnotes?: {
refs?: { [key: string]: number };
list?: FootnoteItem[];
};
docId?: string;
}
/// /////////////////////////////////////////////////////////////////////////////
// Renderer partials
function render_footnote_anchor_name(tokens: Token[], idx: number, options: any, env: FootnoteEnv): string {
const n = Number(tokens[idx].meta.id + 1).toString();
let prefix = '';
if (typeof env.docId === 'string') prefix = `-${env.docId}-`;
return prefix + n;
}
function render_footnote_caption(tokens: Token[], idx: number): string {
let n = Number(tokens[idx].meta.id + 1).toString();
if (tokens[idx].meta.subId > 0) n += `:${tokens[idx].meta.subId}`;
return `[${n}]`;
}
function render_footnote_ref(tokens: Token[], idx: number, options: any, env: FootnoteEnv, slf: Renderer): string {
const id = slf.rules.footnote_anchor_name!(tokens, idx, options, env, slf);
const caption = slf.rules.footnote_caption!(tokens, idx, options, env, slf);
let refid = id;
if (tokens[idx].meta.subId > 0) refid += `:${tokens[idx].meta.subId}`;
return `<sup class="footnote-ref"><a href="#fn${id}" id="fnref${refid}">${caption}</a></sup>`;
}
function render_footnote_block_open(tokens: Token[], idx: number, options: any): string {
return (options.xhtmlOut ? '<hr class="footnotes-sep" />\n' : '<hr class="footnotes-sep">\n') +
'<section class="footnotes">\n' +
'<ol class="footnotes-list">\n';
}
function render_footnote_block_close(): string {
return '</ol>\n</section>\n';
}
function render_footnote_open(tokens: Token[], idx: number, options: any, env: FootnoteEnv, slf: Renderer): string {
let id = slf.rules.footnote_anchor_name!(tokens, idx, options, env, slf);
if (tokens[idx].meta.subId > 0) id += `:${tokens[idx].meta.subId}`;
return `<li id="fn${id}" class="footnote-item">`;
}
function render_footnote_close(): string {
return '</li>\n';
}
function render_footnote_anchor(tokens: Token[], idx: number, options: any, env: FootnoteEnv, slf: Renderer): string {
let id = slf.rules.footnote_anchor_name!(tokens, idx, options, env, slf);
if (tokens[idx].meta.subId > 0) id += `:${tokens[idx].meta.subId}`;
/* ↩ with escape code to prevent display as Apple Emoji on iOS */
return ` <a href="#fnref${id}" class="footnote-backref">\u21a9\uFE0E</a>`;
}
/**
* markdown-it-footnote 插件
* 用于支持脚注语法
*/
export default function footnote_plugin(md: MarkdownIt): void {
const parseLinkLabel = md.helpers.parseLinkLabel;
const isSpace = md.utils.isSpace;
md.renderer.rules.footnote_ref = render_footnote_ref;
md.renderer.rules.footnote_block_open = render_footnote_block_open;
md.renderer.rules.footnote_block_close = render_footnote_block_close;
md.renderer.rules.footnote_open = render_footnote_open;
md.renderer.rules.footnote_close = render_footnote_close;
md.renderer.rules.footnote_anchor = render_footnote_anchor;
// helpers (only used in other rules, no tokens are attached to those)
md.renderer.rules.footnote_caption = render_footnote_caption;
md.renderer.rules.footnote_anchor_name = render_footnote_anchor_name;
// Process footnote block definition
function footnote_def(state: StateBlock, startLine: number, endLine: number, silent: boolean): boolean {
const start = state.bMarks[startLine] + state.tShift[startLine];
const max = state.eMarks[startLine];
// line should be at least 5 chars - "[^x]:"
if (start + 4 > max) return false;
if (state.src.charCodeAt(start) !== 0x5B/* [ */) return false;
if (state.src.charCodeAt(start + 1) !== 0x5E/* ^ */) return false;
let pos: number;
for (pos = start + 2; pos < max; pos++) {
if (state.src.charCodeAt(pos) === 0x20) return false;
if (state.src.charCodeAt(pos) === 0x5D /* ] */) {
break;
}
}
if (pos === start + 2) return false; // no empty footnote labels
if (pos + 1 >= max || state.src.charCodeAt(++pos) !== 0x3A /* : */) return false;
if (silent) return true;
pos++;
const env = state.env as FootnoteEnv;
if (!env.footnotes) env.footnotes = {};
if (!env.footnotes.refs) env.footnotes.refs = {};
const label = state.src.slice(start + 2, pos - 2);
env.footnotes.refs[`:${label}`] = -1;
const token_fref_o = new state.Token('footnote_reference_open', '', 1);
token_fref_o.meta = { label };
token_fref_o.level = state.level++;
state.tokens.push(token_fref_o);
const oldBMark = state.bMarks[startLine];
const oldTShift = state.tShift[startLine];
const oldSCount = state.sCount[startLine];
const oldParentType = state.parentType;
const posAfterColon = pos;
const initial = state.sCount[startLine] + pos - (state.bMarks[startLine] + state.tShift[startLine]);
let offset = initial;
while (pos < max) {
const ch = state.src.charCodeAt(pos);
if (isSpace(ch)) {
if (ch === 0x09) {
offset += 4 - offset % 4;
} else {
offset++;
}
} else {
break;
}
pos++;
}
state.tShift[startLine] = pos - posAfterColon;
state.sCount[startLine] = offset - initial;
state.bMarks[startLine] = posAfterColon;
state.blkIndent += 4;
state.parentType = 'footnote' as any;
if (state.sCount[startLine] < state.blkIndent) {
state.sCount[startLine] += state.blkIndent;
}
state.md.block.tokenize(state, startLine, endLine);
state.parentType = oldParentType;
state.blkIndent -= 4;
state.tShift[startLine] = oldTShift;
state.sCount[startLine] = oldSCount;
state.bMarks[startLine] = oldBMark;
const token_fref_c = new state.Token('footnote_reference_close', '', -1);
token_fref_c.level = --state.level;
state.tokens.push(token_fref_c);
return true;
}
// Process inline footnotes (^[...])
function footnote_inline(state: StateInline, silent: boolean): boolean {
const max = state.posMax;
const start = state.pos;
if (start + 2 >= max) return false;
if (state.src.charCodeAt(start) !== 0x5E/* ^ */) return false;
if (state.src.charCodeAt(start + 1) !== 0x5B/* [ */) return false;
const labelStart = start + 2;
const labelEnd = parseLinkLabel(state, start + 1);
// parser failed to find ']', so it's not a valid note
if (labelEnd < 0) return false;
// We found the end of the link, and know for a fact it's a valid link;
// so all that's left to do is to call tokenizer.
//
if (!silent) {
const env = state.env as FootnoteEnv;
if (!env.footnotes) env.footnotes = {};
if (!env.footnotes.list) env.footnotes.list = [];
const footnoteId = env.footnotes.list.length;
const tokens: Token[] = [];
state.md.inline.parse(
state.src.slice(labelStart, labelEnd),
state.md,
state.env,
tokens
);
const token = state.push('footnote_ref', '', 0);
token.meta = { id: footnoteId };
env.footnotes.list[footnoteId] = {
content: state.src.slice(labelStart, labelEnd),
tokens,
count: 0
};
}
state.pos = labelEnd + 1;
state.posMax = max;
return true;
}
// Process footnote references ([^...])
function footnote_ref(state: StateInline, silent: boolean): boolean {
const max = state.posMax;
const start = state.pos;
// should be at least 4 chars - "[^x]"
if (start + 3 > max) return false;
const env = state.env as FootnoteEnv;
if (!env.footnotes || !env.footnotes.refs) return false;
if (state.src.charCodeAt(start) !== 0x5B/* [ */) return false;
if (state.src.charCodeAt(start + 1) !== 0x5E/* ^ */) return false;
let pos: number;
for (pos = start + 2; pos < max; pos++) {
if (state.src.charCodeAt(pos) === 0x20) return false;
if (state.src.charCodeAt(pos) === 0x0A) return false;
if (state.src.charCodeAt(pos) === 0x5D /* ] */) {
break;
}
}
if (pos === start + 2) return false; // no empty footnote labels
if (pos >= max) return false;
pos++;
const label = state.src.slice(start + 2, pos - 1);
if (typeof env.footnotes.refs[`:${label}`] === 'undefined') return false;
if (!silent) {
if (!env.footnotes.list) env.footnotes.list = [];
let footnoteId: number;
if (env.footnotes.refs[`:${label}`] < 0) {
footnoteId = env.footnotes.list.length;
env.footnotes.list[footnoteId] = { label, count: 0 };
env.footnotes.refs[`:${label}`] = footnoteId;
} else {
footnoteId = env.footnotes.refs[`:${label}`];
}
const footnoteSubId = env.footnotes.list[footnoteId].count;
env.footnotes.list[footnoteId].count++;
const token = state.push('footnote_ref', '', 0);
token.meta = { id: footnoteId, subId: footnoteSubId, label };
}
state.pos = pos;
state.posMax = max;
return true;
}
// Glue footnote tokens to end of token stream
function footnote_tail(state: StateCore): void {
let tokens: Token[] | null = null;
let current: Token[];
let currentLabel: string;
let insideRef = false;
const refTokens: { [key: string]: Token[] } = {};
const env = state.env as FootnoteEnv;
if (!env.footnotes) { return; }
state.tokens = state.tokens.filter(function (tok) {
if (tok.type === 'footnote_reference_open') {
insideRef = true;
current = [];
currentLabel = tok.meta.label;
return false;
}
if (tok.type === 'footnote_reference_close') {
insideRef = false;
// prepend ':' to avoid conflict with Object.prototype members
refTokens[':' + currentLabel] = current;
return false;
}
if (insideRef) { current.push(tok); }
return !insideRef;
});
if (!env.footnotes.list) { return; }
const list = env.footnotes.list;
state.tokens.push(new state.Token('footnote_block_open', '', 1));
for (let i = 0, l = list.length; i < l; i++) {
const token_fo = new state.Token('footnote_open', '', 1);
token_fo.meta = { id: i, label: list[i].label };
state.tokens.push(token_fo);
if (list[i].tokens) {
tokens = [];
const token_po = new state.Token('paragraph_open', 'p', 1);
token_po.block = true;
tokens.push(token_po);
const token_i = new state.Token('inline', '', 0);
token_i.children = list[i].tokens || null;
token_i.content = list[i].content || '';
tokens.push(token_i);
const token_pc = new state.Token('paragraph_close', 'p', -1);
token_pc.block = true;
tokens.push(token_pc);
} else if (list[i].label) {
tokens = refTokens[`:${list[i].label}`] || null;
}
if (tokens) state.tokens = state.tokens.concat(tokens);
let lastParagraph: Token | null;
if (state.tokens[state.tokens.length - 1].type === 'paragraph_close') {
lastParagraph = state.tokens.pop()!;
} else {
lastParagraph = null;
}
const t = list[i].count > 0 ? list[i].count : 1;
for (let j = 0; j < t; j++) {
const token_a = new state.Token('footnote_anchor', '', 0);
token_a.meta = { id: i, subId: j, label: list[i].label };
state.tokens.push(token_a);
}
if (lastParagraph) {
state.tokens.push(lastParagraph);
}
state.tokens.push(new state.Token('footnote_close', '', -1));
}
state.tokens.push(new state.Token('footnote_block_close', '', -1));
}
md.block.ruler.before('reference', 'footnote_def', footnote_def, { alt: ['paragraph', 'reference'] });
md.inline.ruler.after('image', 'footnote_inline', footnote_inline);
md.inline.ruler.after('footnote_inline', 'footnote_ref', footnote_ref);
md.core.ruler.after('inline', 'footnote_tail', footnote_tail);
}