Added "includeJs()" to "page".

* It includes a script in the page
* It uses a callback to ensure any code dependent on the include runs afterwards
* It uses the signal "javaScriptAlertSent" to do the trick (is there another way to be notified of the "onLoad" event from outside the page context?)
* It uses a "private" slot "_appendScriptElement" to pass the script url in the page context (is there a better way?)

examples/phantomwebintro.js

@@ -0,0 +1,19 @@
+// Read the Phantom webpage '#intro' element text using jQuery and "includeJs"
+
+var page = new WebPage();
+
+page.onConsoleMessage = function(msg) {
+    console.log(msg);
+};
+
+page.open("http://www.phantomjs.org", function(status) {
+    if ( status === "success" ) {
+        page.includeJs("http://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.min.js", function() {
+            page.evaluate(function() {
+                console.log("$(\"#intro\").text() -> " + $("#intro").text());
+            });
+            phantom.exit();
+        });
+    }
+});
+

src/bootstrap.js

@@ -83,5 +83,22 @@ window.WebPage = function() {
         throw "Wrong use of WebPage#open";
     };
 
+    page.includeJs = function(scriptUrl, onScriptLoaded) {
+        // Register temporary signal handler for 'alert()'
+        this.javaScriptAlertSent.connect(function(msgFromAlert) {
+            if ( msgFromAlert === scriptUrl ) {
+                // Resource loaded, time to fire the callback
+                onScriptLoaded(scriptUrl);
+                // And disconnect the signal handler
+                try {
+                    this.javaScriptAlertSent.disconnect(this);
+                } catch (e) {}
+            }
+        });
+
+        // Append the script tag to the body
+        this._appendScriptElement(scriptUrl);
+    };
+
     return page;
 }

src/consts.h

@@ -42,4 +42,9 @@
         "el.dispatchEvent(ev);" \
     "})(this);"
 
+#define JS_APPEND_SCRIPT_ELEMENT "var el = document.createElement('script');" \
+    "el.onload = function() { alert('%1'); };" \
+    "el.src = '%1';" \
+    "document.body.appendChild(el);"
+
 #endif // CONSTS_H

src/webpage.cpp

@@ -514,3 +514,7 @@ bool WebPage::injectJs(const QString &jsFilePath) {
     }
     return false;
 }
+
+void WebPage::_appendScriptElement(const QString &scriptUrl) {
+    m_mainFrame->evaluateJavaScript( QString(JS_APPEND_SCRIPT_ELEMENT).arg(scriptUrl) );
+}

src/webpage.h

@@ -73,6 +73,7 @@ public slots:
     QVariant evaluate(const QString &code);
     bool render(const QString &fileName);
     bool injectJs(const QString &jsFilePath);
+    void _appendScriptElement(const QString &scriptUrl);
 
     // moc does not understand QT_VERSION_CHECK and hence the encoded hex
 #if QT_VERSION >= 0x040600