[electron] fix resolution of hostname placeholder

.vscode/launch.json

@@ -33,7 +33,8 @@
         "--no-cluster",
         "--app-project-path=${workspaceRoot}/examples/electron",
         "--remote-debugging-port=9222",
-        "--no-app-auto-install"
+        "--no-app-auto-install",
+        "--plugins=local-dir:../../plugins"
       ],
       "env": {
         "NODE_ENV": "development",
@@ -189,4 +190,4 @@
       ]
     }
   ]
-}
+}

packages/core/src/browser/endpoint.ts

@@ -52,7 +52,7 @@ export class Endpoint {
         return this.location.pathname;
     }
 
-    protected get host(): string {
+    get host(): string {
         if (this.options.host) {
             return this.options.host;
         }

packages/plugin-ext/src/main/browser/webview/webview-environment.ts

@@ -20,6 +20,7 @@ import { Deferred } from '@theia/core/lib/common/promise-util';
 import { EnvVariablesServer } from '@theia/core/lib/common/env-variables';
 import URI from '@theia/core/lib/common/uri';
 import { WebviewExternalEndpoint } from '../../common/webview-protocol';
+import { environment } from '@theia/application-package/lib/environment';
 
 @injectable()
 export class WebviewEnvironment {
@@ -32,9 +33,15 @@ export class WebviewEnvironment {
     @postConstruct()
     protected async init(): Promise<void> {
         try {
-            const variable = await this.environments.getValue(WebviewExternalEndpoint.pattern);
-            const value = variable && variable.value || WebviewExternalEndpoint.defaultPattern;
-            this.externalEndpointHost.resolve(value.replace('{{hostname}}', window.location.host || 'localhost'));
+            let endpointPattern;
+            if (environment.electron.is()) {
+                endpointPattern = WebviewExternalEndpoint.defaultPattern;
+            } else {
+                const variable = await this.environments.getValue(WebviewExternalEndpoint.pattern);
+                endpointPattern = variable && variable.value || WebviewExternalEndpoint.defaultPattern;
+            }
+            const { host } = new Endpoint();
+            this.externalEndpointHost.resolve(endpointPattern.replace('{{hostname}}', host));
         } catch (e) {
             this.externalEndpointHost.reject(e);
         }

packages/plugin-ext/src/main/common/webview-protocol.ts

@@ -18,8 +18,9 @@
  * Each webview should be deployed on a unique origin (https://developer.mozilla.org/en-US/docs/Web/Security/Same-origin_policy)
  * to ensure isolation from browser shared state as cookies, local storage and so on.
  *
- * Use `THEIA_WEBVIEW_EXTERNAL_ENDPOINT` to customize the hostname pattern of a origin.
- * By default is `{{uuid}}.webview.{{hostname}}`. Where `{{uuid}}` is a placeholder for a webview global id.
+ * Default hostname pattern of a origin is `{{uuid}}.webview.{{hostname}}`. Where `{{uuid}}` is a placeholder for a webview global id.
+ * For electron target the default pattern is always used.
+ * For the browser target use `THEIA_WEBVIEW_EXTERNAL_ENDPOINT` env variable to customize it.
  */
 export namespace WebviewExternalEndpoint {
     export const pattern = 'THEIA_WEBVIEW_EXTERNAL_ENDPOINT';

packages/plugin-ext/src/main/node/plugin-service.ts

@@ -22,6 +22,7 @@ import * as express from 'express';
 import { BackendApplicationContribution } from '@theia/core/lib/node/backend-application';
 import { injectable } from 'inversify';
 import { WebviewExternalEndpoint } from '../common/webview-protocol';
+import { environment } from '@theia/application-package/lib/environment';
 
 const pluginPath = (process.env.HOME || process.env.HOMEPATH || process.env.USERPROFILE) + './theia/plugins/';
 
@@ -42,7 +43,13 @@ export class PluginApiContribution implements BackendApplicationContribution {
     }
 
     protected webviewExternalEndpoint(): string {
-        return (process.env[WebviewExternalEndpoint.pattern] || WebviewExternalEndpoint.defaultPattern)
+        let endpointPattern;
+        if (environment.electron.is()) {
+            endpointPattern = WebviewExternalEndpoint.defaultPattern;
+        } else {
+            endpointPattern = process.env[WebviewExternalEndpoint.pattern] || WebviewExternalEndpoint.defaultPattern;
+        }
+        return endpointPattern
             .replace('{{uuid}}', '.+')
             .replace('{{hostname}}', '.+');
     }