markdown-it-graph/dist/index.cjs.js

A markdown-it plugin that parses custom graph syntax like ```graph bar and outputs structured graph data

'use strict';

/** @typedef {import('./index')} */

function graph_plugin(md) {
  const defaultType = 'bar';

  // Add renderer override for "graph" fences
  const originalFence = md.renderer.rules.fence || function (tokens, idx, options, env, self) {
    return self.renderToken(tokens, idx, options);
  };
  md.renderer.rules.fence = function (tokens, idx, options, env, self) {
    const token = tokens[idx];
    const info = token.info.trim();
    const [typeKeyword, graphType = defaultType] = info.split(/\s+/);
    if (typeKeyword !== 'graph') {
      return originalFence(tokens, idx, options, env, self);
    }
    const lines = token.content.trim().split('\n');
    const data = lines.map(line => {
      const [labelPart, valuePart] = line.split('|').map(s => s.trim());
      if (!labelPart || !valuePart) return null;
      const match = valuePart.match(/^([█▉▊▋▌▍▎▏ ]*)([-+]?[\d.]+.*)$/);
      let valueRaw = valuePart;
      if (match && match.length >= 3) {
        valueRaw = match[2] ? match[2].trim() : valuePart;
      }
      const value = parseFloat(valueRaw.replace(/[^0-9.-]/g, ''));
      return {
        label: labelPart,
        value
      };
    }).filter(Boolean);
    const payload = {
      type: graphType,
      data
    };
    return `<graph-block type="${graphType}" data-graph='${JSON.stringify(payload)}'></graph-block>`;
  };

  // Add custom block rule to detect ```graph blocks
  md.block.ruler.before('fence', 'graph_block', function (state, startLine, endLine, silent) {
    const startPos = state.bMarks[startLine] + state.tShift[startLine];
    const maxPos = state.eMarks[startLine];
    const marker = state.src.slice(startPos, maxPos).trim();
    if (!marker.startsWith('```graph')) return false;
    if (silent) return true;
    let nextLine = startLine;
    while (++nextLine < endLine) {
      const lineStart = state.bMarks[nextLine] + state.tShift[nextLine];
      const lineEnd = state.eMarks[nextLine];
      const lineText = state.src.slice(lineStart, lineEnd).trim();
      if (lineText.startsWith('```')) break;
    }
    const token = state.push('fence', 'code', 0);
    token.info = marker.slice(3).trim(); // e.g., "graph bar"
    token.content = state.getLines(startLine + 1, nextLine, state.tShift[startLine], true);
    token.map = [startLine, nextLine + 1];
    token.markup = '```';
    state.line = nextLine + 1;
    return true;
  });
}

module.exports = graph_plugin;