#5742 add line magic highlighting in Lab

js/lab/src/plugin/codeEditor.ts

@@ -18,10 +18,13 @@ import { CodeMirrorEditor } from "@jupyterlab/codemirror";
 import { Cell, CodeCell } from '@jupyterlab/cells';
 
 import 'codemirror/mode/groovy/groovy';
+import {NotebookPanel} from "@jupyterlab/notebook";
 
 const LINE_COMMENT_CHAR = '//';
+const LINE_MAGIC_MODE = 'line_magic';
+const CodeMirror = require("codemirror");
 
-export const registerCommentOutCmd = (panel) => {
+export const registerCommentOutCmd = (panel: NotebookPanel) => {
   const cells = panel.notebook.widgets || [];
 
   cells
@@ -50,3 +53,84 @@ const setCodeMirrorLineComment = (cell: Cell) => {
   mode.lineComment = LINE_COMMENT_CHAR;
   doc.mode = mode;
 };
+
+export function extendHighlightModes(panel: NotebookPanel) {
+  const cells = panel.notebook.widgets || [];
+
+  cells
+    .filter((cell) => (cell.editor instanceof CodeMirrorEditor))
+    .forEach(setLineMagicForCell);
+
+  CodeMirror.defineInitHook(addLineMagicsOverlay);
+}
+
+function setLineMagicForCell(cell: Cell) {
+  if (!(cell instanceof CodeCell)) {
+    return;
+  }
+
+  addLineMagicsOverlay((<CodeMirrorEditor>cell.editor).editor);
+}
+
+const lineMagicOverlay = {
+  startState() {
+    return { firstMatched: false, inMagicLine: false };
+  },
+
+  token(stream, state) {
+    if (!state.firstMatched) {
+      state.firstMatched = true;
+
+      if (stream.match(/^%\w+/, false)) {
+        state.inMagicLine = true;
+      }
+    }
+
+    if (state.inMagicLine) {
+      stream.eat(() => true);
+
+      if (stream.eol()) {
+        state.inMagicLine = false;
+      }
+
+      return LINE_MAGIC_MODE;
+    }
+
+    stream.skipToEnd();
+
+    return null;
+  }
+};
+
+export function autoHighlightLineMagics(code_mirror) {
+  const current_mode = code_mirror.getOption('mode');
+  const first_line = code_mirror.getLine(0);
+  const re = /^%\w+/;
+
+  if (current_mode === LINE_MAGIC_MODE) {
+    return;
+  }
+
+  if (first_line.match(re) !== null) {
+    // Add an overlay mode to recognize the first line as "line magic" instead
+    // of the mode used for the rest of the cell.
+    CodeMirror.defineMode(LINE_MAGIC_MODE, (config) => {
+      return CodeMirror.overlayMode(CodeMirror.getMode(config, current_mode), lineMagicOverlay);
+    });
+
+    code_mirror.setOption('mode', LINE_MAGIC_MODE);
+  }
+}
+
+export function addLineMagicsOverlay(editor: any) {
+  autoHighlightLineMagics(editor);
+
+  editor.off("focus", autoHighlightLineMagics);
+  editor.on("focus", autoHighlightLineMagics);
+  editor.off("change", autoHighlightLineMagics);
+  editor.on("change", autoHighlightLineMagics);
+  editor.off("blur", autoHighlightLineMagics);
+  editor.on("blur", autoHighlightLineMagics);
+
+  editor.refresh();
+}

js/lab/src/plugin/index.ts

@@ -21,7 +21,7 @@ import { INotebookModel, NotebookPanel } from '@jupyterlab/notebook';
 import { JupyterLab } from "@jupyterlab/application";
 import { ISettingRegistry } from "@jupyterlab/coreutils";
 import { registerCommTargets } from './comm';
-import { registerCommentOutCmd } from './codeEditor';
+import {extendHighlightModes, registerCommentOutCmd} from './codeEditor';
 import { enableInitializationCellsFeature } from './initializationCells';
 import UIOptionFeaturesHelper from "./UIOptionFeaturesHelper";
 
@@ -55,6 +55,7 @@ class BeakerxExtension implements DocumentRegistry.WidgetExtension {
     let settings = this.settings;
 
     Promise.all([panel.ready, panel.session.ready, context.ready]).then(function() {
+      extendHighlightModes(panel);
       enableInitializationCellsFeature(panel);
       registerCommentOutCmd(panel);
       registerCommTargets(panel, context);

js/notebook/src/extension.js

@@ -75,7 +75,7 @@ define([
   var Autotranslation = require('./extension/autotranslation').Autotranslation;
   var BeakerXKernel = require('./extension/kernel').BeakerXKernel;
   var bkCoreManager = require('./shared/bkCoreManager').default;
-  var bxCodeMirror = require('./extension/codeMirror').default;
+  var bxCodeEditor = require('./extension/codeEditor').default;
 
   var inNotebook = !Jupyter.NotebookList;
   var mod_name = 'init_cell';
@@ -112,8 +112,8 @@ define([
     if (inNotebook) {
       // setup things to run on loading config/notebook
 
-      bxCodeMirror.extendWithLineComment(Jupyter, CodeMirror);
-      bxCodeMirror.extendHighlightModes(Jupyter);
+      bxCodeEditor.extendWithLineComment(Jupyter, CodeMirror);
+      bxCodeEditor.extendHighlightModes(Jupyter);
 
       Jupyter.notebook.config.loaded
         .then(function update_options_from_config() {