Add onSearch activationEvent for search providers

extensions/search-rg/package.json

@@ -24,6 +24,7 @@
   },
   "scripts": {},
   "activationEvents": [
+    "onSearch:file",
     "*"
   ],
   "main": "./out/extension",

src/vs/workbench/services/extensions/common/extensionsRegistry.ts

@@ -220,6 +220,11 @@ const schema: IJSONSchema = {
 						description: nls.localize('vscode.extension.activationEvents.workspaceContains', 'An activation event emitted whenever a folder is opened that contains at least a file matching the specified glob pattern.'),
 						body: 'workspaceContains:${4:filePattern}'
 					},
+					{
+						label: 'onSearch',
+						description: nls.localize('vscode.extension.activationEvents.onSearch', 'An activation event emitted whenever a search is started in the folder with the given scheme.'),
+						body: 'onSearch:${7:scheme}'
+					},
 					{
 						label: 'onView',
 						body: 'onView:${5:viewId}',

src/vs/workbench/services/search/node/searchService.ts

@@ -125,7 +125,10 @@ export class SearchService implements ISearchService {
 					}
 				});
 
-			const providerPromise = this.extensionService.whenInstalledExtensionsRegistered().then(() => {
+			const schemesInQuery = query.folderQueries.map(fq => fq.folder.scheme);
+			const providerActivations = schemesInQuery.map(scheme => this.extensionService.activateByEvent(`onSearch:${scheme}`));
+
+			const providerPromise = TPromise.join(providerActivations).then(() => {
 				// TODO@roblou this is not properly waiting for search-rg to finish registering itself
 				// If no search provider has been registered for the 'file' schema, fall back on DiskSearch
 				const providers = [