Support Page.{Alert,Confirm,Prompt,BeforeUnload} events

This patch adds Page events to fire when javascript dialogs
get opened.

lib/Page.js

@@ -60,7 +60,7 @@ class Page extends EventEmitter {
         client.on('Network.responseReceived', event => this.emit(Page.Events.ResponseReceived, event.response));
         client.on('Network.loadingFailed', event => this.emit(Page.Events.ResourceLoadingFailed, event));
         client.on('Runtime.consoleAPICalled', event => this._onConsoleAPI(event));
-        client.on('Page.javascriptDialogOpening', dialog => this.emit(Page.Events.Dialog, dialog));
+        client.on('Page.javascriptDialogOpening', event => this._onDialog(event));
         client.on('Runtime.exceptionThrown', exception => this._handleException(exception.exceptionDetails));
     }
 
@@ -207,6 +207,20 @@ class Page extends EventEmitter {
         this.emit(Page.Events.ConsoleMessage, values.join(' '));
     }
 
+    _onDialog(event) {
+        var eventType = null;
+        if (event.type === 'alert')
+            eventType = Page.Events.Alert;
+        else if (event.type === 'confirm')
+            eventType = Page.Events.Confirm;
+        else if (event.type === 'prompt')
+            eventType = Page.Events.Prompt;
+        else if (event.type === 'beforeunload')
+            eventType = Page.Events.BeforeUnload;
+        if (eventType)
+            this.emit(eventType, event.message);
+    }
+
     /**
      * @param {boolean} accept
      * @param {string} promptText
@@ -416,9 +430,12 @@ Page.ScreenshotTypes = {
 };
 
 Page.Events = {
+    Alert: 'alert',
+    BeforeUnload: 'beforeunload',
+    Confirm: 'confirm',
     ConsoleMessage: 'consolemessage',
-    Dialog: 'dialog',
     Exception: 'exception',
+    Prompt: 'prompt',
     ResourceLoadingFailed: 'resourceloadingfailed',
     ResponseReceived: 'responsereceived',
 };

phantomjs/WebPage.js

@@ -57,14 +57,16 @@ class WebPage {
 
         this.libraryPath = path.dirname(scriptPath);
 
-        this._onConfirm = undefined;
+        this._onConfirmCallback = undefined;
+        this._onAlertCallback = undefined;
         this._onError = noop;
 
         this._pageEvents = new AsyncEmitter(this._page);
         this._pageEvents.on(PageEvents.ResponseReceived, response => this._onResponseReceived(response));
         this._pageEvents.on(PageEvents.ResourceLoadingFailed, event => (this.onResourceError || noop).call(null, event));
         this._pageEvents.on(PageEvents.ConsoleMessage, msg => (this.onConsoleMessage || noop).call(null, msg));
-        this._pageEvents.on(PageEvents.Dialog, dialog => this._onDialog(dialog));
+        this._pageEvents.on(PageEvents.Confirm, message => this._onConfirm(message));
+        this._pageEvents.on(PageEvents.Alert, message => this._onAlert(message));
         this._pageEvents.on(PageEvents.Exception, (exception, stack) => (this._onError || noop).call(null, exception, stack));
     }
 
@@ -156,7 +158,7 @@ class WebPage {
      * @return {(function()|undefined)}
      */
     get onConfirm() {
-        return this._onConfirm;
+        return this._onConfirmCallback;
     }
 
     /**
@@ -165,16 +167,45 @@ class WebPage {
     set onConfirm(handler) {
         if (typeof handler !== 'function')
             handler = undefined;
-        this._onConfirm = handler;
+        this._onConfirmCallback = handler;
     }
 
-    _onDialog(dialog) {
+    /**
-        if (!this._onConfirm)
+     * @param {string} message
+     */
+    _onConfirm(message) {
+        if (!this._onConfirmCallback)
             return;
-        var accept = this._onConfirm.call(null);
+        var accept = this._onConfirmCallback.call(null, message);
         await(this._page.handleDialog(accept));
     }
 
+    /**
+     * @return {(function()|undefined)}
+     */
+    get onAlert() {
+        return this._onAlertCallback;
+    }
+
+    /**
+     * @param {function()} handler
+     */
+    set onAlert(handler) {
+        if (typeof handler !== 'function')
+            handler = undefined;
+        this._onAlertCallback = handler;
+    }
+
+    /**
+     * @param {string} message
+     */
+    _onAlert(message) {
+        if (!this._onAlertCallback)
+            return;
+        this._onAlertCallback.call(null, message);
+        await(this._page.handleDialog(true));
+    }
+
     /**
      * @return {string}
      */