const zlib = require('zlib') // ------------------------------------ // Markdown - Kroki Preprocessor // ------------------------------------ module.exports = { init (mdinst, conf) { mdinst.use((md, opts) => { const openMarker = opts.openMarker || '```kroki' const openChar = openMarker.charCodeAt(0) const closeMarker = opts.closeMarker || '```' const closeChar = closeMarker.charCodeAt(0) const server = opts.server || 'https://kroki.io' md.block.ruler.before('fence', 'kroki', (state, startLine, endLine, silent) => { let nextLine let markup let params let token let i let autoClosed = false let start = state.bMarks[startLine] + state.tShift[startLine] let max = state.eMarks[startLine] // Check out the first character quickly, // this should filter out most of non-uml blocks // if (openChar !== state.src.charCodeAt(start)) { return false } // Check out the rest of the marker string // for (i = 0; i < openMarker.length; ++i) { if (openMarker[i] !== state.src[start + i]) { return false } } markup = state.src.slice(start, start + i) params = state.src.slice(start + i, max) // Since start is found, we can report success here in validation mode // if (silent) { return true } // Search for the end of the block // nextLine = startLine for (;;) { nextLine++ if (nextLine >= endLine) { // unclosed block should be autoclosed by end of document. // also block seems to be autoclosed by end of parent break } start = state.bMarks[nextLine] + state.tShift[nextLine] max = state.eMarks[nextLine] if (start < max && state.sCount[nextLine] < state.blkIndent) { // non-empty line with negative indent should stop the list: // - ``` // test break } if (closeChar !== state.src.charCodeAt(start)) { // didn't find the closing fence continue } if (state.sCount[nextLine] > state.sCount[startLine]) { // closing fence should not be indented with respect of opening fence continue } let closeMarkerMatched = true for (i = 0; i < closeMarker.length; ++i) { if (closeMarker[i] !== state.src[start + i]) { closeMarkerMatched = false break } } if (!closeMarkerMatched) { continue } // make sure tail has spaces only if (state.skipSpaces(start + i) < max) { continue } // found! autoClosed = true break } let contents = state.src .split('\n') .slice(startLine + 1, nextLine) .join('\n') // We generate a token list for the alt property, to mimic what the image parser does. let altToken = [] // Remove leading space if any. let alt = params ? params.slice(1) : 'uml diagram' state.md.inline.parse( alt, state.md, state.env, altToken ) let firstlf = contents.indexOf('\n') if (firstlf === -1) firstlf = undefined let diagramType = contents.substring(0, firstlf) contents = contents.substring(firstlf + 1) let result = zlib.deflateSync(contents).toString('base64').replace(/\+/g, '-').replace(/\//g, '_') token = state.push('kroki', 'img', 0) // alt is constructed from children. No point in populating it here. token.attrs = [ [ 'src', `${server}/${diagramType}/svg/${result}` ], [ 'alt', '' ], ['class', 'uml-diagram prefetch-candidate'] ] token.block = true token.children = altToken token.info = params token.map = [ startLine, nextLine ] token.markup = markup state.line = nextLine + (autoClosed ? 1 : 0) return true }, { alt: [ 'paragraph', 'reference', 'blockquote', 'list' ] }) md.renderer.rules.kroki = md.renderer.rules.image }, { openMarker: conf.openMarker, closeMarker: conf.closeMarker, server: conf.server }) } }