#3061 Lazy loading auto derived path

packages/mermaid/src/Diagram.ts

@@ -1,7 +1,7 @@
 import * as configApi from './config';
 import { log } from './logger';
-import { getDiagram } from './diagram-api/diagramAPI';
-import { detectType } from './diagram-api/detectType';
+import { getDiagram, loadDiagram } from './diagram-api/diagramAPI';
+import { detectType, getPathForDiagram } from './diagram-api/detectType';
 import { isDetailedError } from './utils';
 export class Diagram {
   type = 'graph';
@@ -67,3 +67,21 @@ export class Diagram {
 }
 
 export default Diagram;
+
+// eslint-disable-next-line @typescript-eslint/ban-types
+export const getDiagramFromText = async (txt: string, parseError?: Function) => {
+  const type = detectType(txt, configApi.getConfig());
+  try {
+    // Trying to find the diagram
+    getDiagram(type);
+  } catch (error) {
+    // Diagram not avaiable, loading it
+    const path = getPathForDiagram(type);
+    // await loadDiagram('./packages/mermaid-mindmap/dist/mermaid-mindmap.js');
+    await loadDiagram(path + 'mermaid-' + type + '.js');
+    // new diagram will try getDiagram again and if fails then it is a valid throw
+  }
+  // If either of the above worked, we have the diagram
+  // logic and can continue
+  return new Diagram(txt, parseError);
+};

packages/mermaid/src/dagre-wrapper/mermaid-graphlib.js

@@ -39,8 +39,6 @@ const edgeInCluster = (edge, clusterId) => {
     log.debug('Tilt, ', clusterId, ',not in decendants');
     return false;
   }
-  log.info('Here ');
-
   if (decendants[clusterId].indexOf(edge.v) >= 0) return true;
   if (isDecendant(edge.v, clusterId)) return true;
   if (isDecendant(edge.w, clusterId)) return true;

packages/mermaid/src/diagram-api/detectType.ts

@@ -1,12 +1,13 @@
 import { MermaidConfig } from '../config.type';
 
 export type DiagramDetector = (text: string, config?: MermaidConfig) => boolean;
+export type DetectorRecord = { detector: DiagramDetector; path: string };
 
 const directive =
   /[%]{2}[{]\s*(?:(?:(\w+)\s*:|(\w+))\s*(?:(?:(\w+))|((?:(?![}][%]{2}).|\r?\n)*))?\s*)(?:[}][%]{2})?/gi;
 const anyComment = /\s*%%.*\n/gm;
 
-const detectors: Record<string, DiagramDetector> = {};
+const detectors: Record<string, DetectorRecord> = {};
 
 /**
  * @function detectType Detects the type of the graph text. Takes into consideration the possible
@@ -36,8 +37,8 @@ export const detectType = function (text: string, config?: MermaidConfig): strin
 
   // console.log(detectors);
 
-  for (const [key, detector] of Object.entries(detectors)) {
-    if (detector(text, config)) {
+  for (const [key, detectorRecord] of Object.entries(detectors)) {
+    if (detectorRecord.detector(text, config)) {
       return key;
     }
   }
@@ -46,6 +47,13 @@ export const detectType = function (text: string, config?: MermaidConfig): strin
   return 'flowchart';
 };
 
-export const addDetector = (key: string, detector: DiagramDetector) => {
-  detectors[key] = detector;
+export const addDetector = (key: string, detector: DiagramDetector, path: string) => {
+  detectors[key] = { detector, path };
+};
+
+export const getPathForDiagram = (id: string) => {
+  const detectorRecord = detectors[id];
+  if (detectorRecord) {
+    return detectorRecord.path;
+  }
 };

packages/mermaid/src/diagram-api/diagram-orchestration.ts

@@ -112,7 +112,7 @@ const registerDiagramAndDetector = (
   detector: DiagramDetector
 ) => {
   registerDiagram(id, diagram);
-  registerDetector(id, detector);
+  registerDetector(id, detector, '');
 };
 
 export const addDiagrams = () => {
@@ -136,9 +136,9 @@ export const addDiagrams = () => {
       init: () => {
         // no op
       },
-    }
+    },
+    (text) => text.toLowerCase().trim() === 'error'
   );
-  registerDetector('error', (text) => text.toLowerCase().trim() === 'error');
 
   registerDiagramAndDetector(
     'c4',

packages/mermaid/src/diagram-api/diagramAPI.spec.ts

@@ -19,7 +19,7 @@ describe('DiagramAPI', () => {
     const detector: DiagramDetector = (str: string) => {
       return str.match('loki') !== null;
     };
-    registerDetector('loki', detector);
+    registerDetector('loki', detector, '');
     registerDiagram(
       'loki',
       {

packages/mermaid/src/diagram-api/diagramAPI.ts

@@ -32,8 +32,8 @@ export interface Detectors {
   [key: string]: DiagramDetector;
 }
 
-export const registerDetector = (id: string, detector: DiagramDetector) => {
-  addDetector(id, detector);
+export const registerDetector = (id: string, detector: DiagramDetector, path: string) => {
+  addDetector(id, detector, path);
 };
 
 export const registerDiagram = (
@@ -61,3 +61,19 @@ export const getDiagram = (name: string): DiagramDefinition => {
   }
   throw new Error(`Diagram ${name} not found.`);
 };
+
+/**
+ *
+ * @param sScriptSrc
+ */
+export const loadDiagram = (sScriptSrc: string) =>
+  new Promise((resolve) => {
+    const oHead = document.getElementsByTagName('HEAD')[0];
+    const oScript = document.createElement('script');
+    oScript.type = 'text/javascript';
+    oScript.src = sScriptSrc;
+    oHead.appendChild(oScript);
+    oScript.onload = () => {
+      resolve(true);
+    };
+  });

packages/mermaid/src/mermaid.ts

@@ -54,8 +54,8 @@ const init = function (
 ) {
   try {
     log.info('Detectors in init', mermaid.detectors); // eslint-disable-line
-    mermaid.detectors.forEach(({ id, detector }) => {
-      addDetector(id, detector);
+    mermaid.detectors.forEach(({ id, detector, path }) => {
+      addDetector(id, detector, path);
     });
     initThrowsErrors(config, nodes, callback);
   } catch (e) {

packages/mermaid/src/mermaidAPI.ts

@@ -22,7 +22,7 @@ import classDb from './diagrams/class/classDb';
 import flowDb from './diagrams/flowchart/flowDb';
 import flowRenderer from './diagrams/flowchart/flowRenderer';
 import ganttDb from './diagrams/gantt/ganttDb';
-import Diagram from './Diagram';
+import Diagram, { getDiagramFromText } from './Diagram';
 import errorRenderer from './diagrams/error/errorRenderer';
 import { attachFunctions } from './interactionDb';
 import { log, setLogLevel } from './logger';
@@ -115,12 +115,12 @@ export const decodeEntities = function (text: string): string {
  *   element will be removed when rendering is completed.
  * @returns {void}
  */
-const render = function (
+const render = async function (
   id: string,
   text: string,
   cb: (svgCode: string, bindFunctions?: (element: Element) => void) => void,
   container?: Element
-): void {
+): Promise<void> {
   if (!hasLoadedDiagrams) {
     addDiagrams();
     hasLoadedDiagrams = true;
@@ -232,7 +232,8 @@ const render = function (
   let diag;
   let parseEncounteredException;
   try {
-    diag = new Diagram(text);
+    // diag = new Diagram(text);
+    diag = await getDiagramFromText(text);
   } catch (error) {
     diag = new Diagram('error');
     parseEncounteredException = error;