[codemirror] Added mime type service

src/codeeditor/mimetype.ts

@@ -21,16 +21,9 @@ interface IEditorMimeTypeService {
    * Returns a mime type for the given file path.
    * 
    * #### Notes
-   * If a mime type cannot be found returns the defaul mime type `text/plain`, never `null`.  
+   * If a mime type cannot be found returns the defaul mime type `text/plain`, never `null`.
    */
   getMimeTypeForPath(path: string): string;
-  /**
-   * Returns a mime type for the given file extension.
-   * 
-   * #### Notes
-   * If a mime type cannot be found returns the defaul mime type `text/plain`, never `null`.  
-   */
-  getMimeTypeForExtension(path: string): string;
 }
 
 /**

src/codemirror/mimetype.ts

@@ -0,0 +1,56 @@
+// Copyright (c) Jupyter Development Team.
+// Distributed under the terms of the Modified BSD License.
+
+import {
+  nbformat
+} from '@jupyterlab/services';
+
+import {
+  IEditorMimeTypeService
+} from '../codeeditor';
+
+import {
+  findMode
+} from './index';
+
+/**
+ * The mime type service for CodeMirror.
+ */
+export
+class CodeMirrorMimeTypeService implements IEditorMimeTypeService {
+  /**
+   * Returns a mime type for the given language info.
+   * 
+   * #### Notes
+   * If a mime type cannot be found returns the defaul mime type `text/plain`, never `null`.  
+   */
+  getMimeTypeForLanguage(info: nbformat.ILanguageInfoMetadata): string {
+    if (info.codemirror_mode) {
+      return findMode(info.codemirror_mode as any).mime;
+    }
+    let mode = CodeMirror.findModeByMIME(info.mimetype || '');
+    if (mode) {
+      return info.mimetype!;
+    }
+    let ext = info.file_extension || '';
+    ext = ext.split('.').slice(-1)[0];
+    mode = CodeMirror.findModeByExtension(ext || '');
+    if (mode) {
+      return mode.mime;
+    }
+    mode = CodeMirror.findModeByName(info.name || '');
+    return mode ? mode.mime : IEditorMimeTypeService.defaultMimeType;
+  }
+  /**
+   * Returns a mime type for the given file path.
+   * 
+   * #### Notes
+   * If a mime type cannot be found returns the defaul mime type `text/plain`, never `null`.  
+   */
+  getMimeTypeForPath(path: string): string {
+    const index = path.lastIndexOf('.');
+    const extension = index === -1 ? path : path.substring(index);
+    const mode = CodeMirror.findModeByExtension(extension);
+    return mode ? mode.mime : IEditorMimeTypeService.defaultMimeType;
+  }
+}