1 files changed, 225 insertions, 0 deletions
diff --git a/doc/src/declarative/javascriptblocks.qdoc b/doc/src/declarative/javascriptblocks.qdoc
new file mode 100644
index 0000000000..98183bbac8
--- /dev/null
+++ b/doc/src/declarative/javascriptblocks.qdoc
@@ -0,0 +1,225 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+\page qdeclarativejavascript.html
+\title JavaScript Blocks
+
+QML encourages building UIs declaratively, using \l {Property Binding} and the 
+composition of existing \l {QML Elements}.  If imperative code is required to implement 
+more advanced behavior, the \l Script element can be used to add JavaScript code directly 
+to a QML file, or to include an external JavaScript file.
+
+The \l Script element is a QML language \e intrinsic.  It can be used anywhere in a
+QML file, \e except as the root element of a file or sub-component, but cannot be 
+assigned to an object property or given an id.  The included JavaScript is evaluated 
+in a scope chain.  The \l {QML Scope} documentation covers the specifics of scoping 
+in QML.  
+
+A restriction on the JavaScript used in QML is that you cannot add new members to the
+global object. This happens transparently when you try to use a variable without
+declaring it, and so declaring local variables is required when using Java script in
+QML.
+
+The global object in QML has a variety of helper functions added to it, to aid UI
+implementation. See \l{QML Global Object} for further details.
+
+Note that if you are adding a function that should be called by external elements,
+you do not need the \l Script element. See \l {Extending types from QML#Adding new methods}
+{Adding new methods} for information about adding slots that can be called externally.
+
+\section1 Inline Script
+
+Small blocks of JavaScript can be included directly inside a \l {QML Document} as
+the body of the \l Script element.
+
+\code
+Rectangle {
+    Script {
+        function factorial(a) {
+            a = Integer(a);
+            if (a <= 0)
+                return 1;
+            else 
+                return a * factorial(a - 1);
+        }
+    }
+}
+\endcode
+
+Good programming practice dictates that only small script snippets should be written 
+inline.  QML prohibits the declaration of anything other than functions in an inline
+script block.  For example, the following script is illegal as an inline script block 
+as it declares the non-function variable \c lastResult.
+
+\code
+// Illegal inline code block
+var lastResult = 0
+function factorial(a) {
+    a = Integer(a);
+    if (a <= 0) 
+        lastResult = 1;
+    else 
+        lastResult = a * factorial(a - 1);
+    return lastResult;
+}
+\endcode
+
+\section1 Including an External File
+
+To avoid cluttering the QML file, large script blocks should be in a separate file.
+The \l Script element's \c source property is used to load script from an external
+file.
+
+If the previous factorial code that was illegal as an inline script block was saved
+into a "factorial.js" file, it could be included like this.
+
+\code
+Rectangle {
+    Script { 
+        source: "factorial.js"
+    }
+}
+\endcode
+
+The \c source property may reference a relative file, or an absolute path.  In the
+case of a relative file, the location is resolved relative to the location of the
+\l {QML Document} that contains the \l Script element.  If the script file is not 
+accessible, an error will occur.  If the source is on a network resource, the
+enclosing QML document will remain in the \l {QDeclarativeComponent::status()}{waiting state}
+until the script has been retrieved.
+
+\section1 Running Script at Startup
+
+It is occasionally necessary to run a block of JavaScript code at application (or
+component instance) "startup".  While it is tempting to just include the startup
+script as \e {global code} in an external script file, this can have severe limitations
+as the QML environment may not have been fully established.  For example, some objects 
+might not have been created or some \l {Property Binding}s may not have been run.
+\l {QML Script Restrictions} covers the exact limitations of global script code.
+
+The QML \l Component element provides an \e attached \c onCompleted property that
+can be used to trigger the execution of script code at startup after the
+QML environment has been completely established.
+
+The following QML code shows how to use the \c Component::onCompleted property.
+
+\code
+Rectangle {
+    Script {
+        function startupFunction() {
+            // ... startup code
+        }
+    }
+
+    Component.onCompleted: startupFunction();
+}
+\endcode
+
+Any element in a QML file - including nested elements and nested QML component 
+instances - can use this attached property.  If there is more than one script to
+execute at startup, they are run sequentially in an undefined order.
+
+\section1 QML Script Restrictions
+
+QML \l Script blocks contain standard JavaScript code.  QML introduces the following
+restrictions.
+
+\list
+\o Script code cannot modify the global object.
+
+In QML, the global object is constant - existing properties cannot be modified or 
+deleted, and no new properties may be created.
+
+Most JavaScript programs do not explicitly modify the global object.  However, 
+JavaScript's automatic creation of undeclared variables is an implicit modification
+of the global object, and is prohibited in QML.
+
+Assuming that the \c a variable does not exist in the scope chain, the following code 
+is illegal in QML.
+
+\code
+// Illegal modification of undeclared variable
+a = 1;
+for (var ii = 1; ii < 10; ++ii) a = a * ii;
+    console.log("Result: " + a);
+\endcode
+
+It can be trivially modified to this legal code.
+
+\code
+var a = 1;
+for (var ii = 1; ii < 10; ++ii) a = a * ii;
+    console.log("Result: " + a);
+\endcode
+
+Any attempt to modify the global object - either implicitly or explicitly - will 
+cause an exception.  If uncaught, this will result in an warning being printed, 
+that includes the file and line number of the offending code.
+
+\o Global code is run in a reduced scope
+
+During startup, if a \l Script block includes an external file with "global"
+code, it is executed in a scope that contains only the external file itself and
+the global object.  That is, it will not have access to the QML objects and 
+properties it \l {QML Scope}{normally would}.
+
+Global code that only accesses script local variable is permitted.  This is an 
+example of valid global code.
+
+\code
+var colors = [ "red", "blue", "green", "orange", "purple" ];
+\endcode
+
+Global code that accesses QML objects will not run correctly.
+
+\code
+// Invalid global code - the "rootObject" variable is undefined
+var initialPosition = { rootObject.x, rootObject.y }
+\endcode
+
+This restriction exists as the QML environment is not yet fully established.  
+To run code after the environment setup has completed, refer to 
+\l {Running Script at Startup}.
+
+\endlist
+
+*/