[Interest] Accessing the raw value of QQmlScriptString (QDeclarativeScriptString::script)

[Michael Brasser]

Hi Jan,
> From: jkt at flaska.net
> To: interest at qt-project.org
> Date: Wed, 4 Sep 2013 16:06:26 +0200
> Subject: [Interest] Accessing the raw value of QQmlScriptString (QDeclarativeScriptString::script)
> > ...
> 
> As it is right now, the application is using QtDeclarative for parsing the 
> definitions of the allowed data types. An internal data structure is 
> created and the actual string "price < 666 && procured >= 2012" is stored 
> for later use. The GUI of this application is based on QGraphicsScene, and 
> when it is time to validate the object properties, a throwaway 
> QDeclarativeExpression is created, we feed its context object actual data 
> via setContextProperty() calls, and in the end evaluate the expression. 
> Now, this specific case describes a pretty trivial concept which is 
> expressible by simple boundary checking, but we want to support more 
> complicated expressions including function calls to some utility JS 
> library.


The QQmlExpression constructor that takes a QQmlScriptString allows setting a custom context and scope object to replace the default one provided by the QQmlScriptString. Is this enough to accomplish what you need?


> Can I somehow access (and reuse in an QQmlExpression later) the raw, 
> unprocessed script value in Qt5's QtQML? Why was the script() method 
> removed in Qt5, and would you object to a patch adding it back? Is that 
> feasible, technically?


This was removed in commit aa25ad8d5f476d6db59012a122833ebe677eaf69 ("Allow for future optimization by encapsulating the raw script data."). Unfortunately I do not remember the details of the optimizations being discussed at the time (it may have been related to memory consumption, or to pre-compiling QML, or to early prototypes of v4).
Regards,Michael 		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20130904/9f341831/attachment.html>