It actually seems like doable. As documented section "QVariantList and QVariantMap to JavaScript Array and Object" on the "Data Type Conversion Between QML and C++ <http://doc.qt.io/qt-5/qtqml-cppintegration-data.html>",
"passing a QVariantList <http://doc.qt.io/qt-5/qvariant.html#QVariantList-typedef> and a QVariantMap <http://doc.qt.io/qt-5/qvariant.html#QVariantMap-typedef>, which are automatically converted to JavaScript array and object values, repectively" So I assume it is possible to implement "initialProperties" property for QQuickLoader class, like on the commit <https://codereview.qt-project.org/#/c/3072/> of the old Qt days. But why no one have implemented it before, it disorienting. It might requires more knowledge then this? 2016-04-13 16:17 GMT+03:00 Jérôme Godbout <jer...@bodycad.com>: > I agree, this would be difficult to know if this should create a binding > or simply copy the current value. This is why I was proposing the function > where we could go with either = or Qt.binding() to have full control on > it. Nice to see this was there at some point, I wonder why they removed it > or never integrate it. > > On Wed, Apr 13, 2016 at 2:07 AM, Sina Dogru <sinado...@gmail.com> wrote: > >> It's sad that the imperative setSource() function can set those property >>> and the declarative way is not. >>> >> >> It would also be great but to make something a property instead of a >> function where it is much easier, then there should be a public and >> QMetaType known type.Thats why seems like hard to make it possible. >> >> 2016-04-04 16:31 GMT+03:00 Jérôme Godbout <jer...@bodycad.com>: >> >>> Thanks for pointing this out, but I was aware of that. Sometime a >>> default value is impossible (null) making bad behavior or bad binding, >>> primitive type can always have default value that make sense that way but >>> complex object don't. >>> It's sad that the imperative setSource() function can set those property >>> and the declarative way is not. >>> >>> On Sun, Apr 3, 2016 at 11:10 AM, ekke <e...@ekkes-corner.org> wrote: >>> >>>> if you want to refer to a property as 'model.i' and there are >>>> situations where 'model' doesn't exist always, >>>> it's easy to avoid error messages: >>>> >>>> model? model.i : 42 >>>> >>>> this way you can set a default value while model is null >>>> (haven't tried this yet with Qt 5.6 but I'm doing it this way in >>>> BlackBerry 10 Cascades) >>>> >>>> ekke >>>> >>>> Am 01.04.16 um 16:05 schrieb Jérôme Godbout: >>>> >>>> Yes, but the binding loaded object internal binding are printing error, >>>> since the object is created without the input, then the external binding >>>> are created. They will get eventually correct, but the console will be >>>> filled with error message and I try to avoid that at all cost. Here's a >>>> simple example that will complain about unable to access i and j of >>>> undefined / assign undefined to width and height (this example is a bit >>>> stupid but just a demo to show the problems with more complex model and >>>> object): >>>> >>>> // MyComponent.qml >>>> Item >>>> { >>>> property var model >>>> width: model.i >>>> height: model.j >>>> } >>>> >>>> // Main.qml >>>> MyModel >>>> { >>>> id: myModel_ >>>> property int i: 24 >>>> property int j: 12 >>>> } >>>> >>>> Loader >>>> { >>>> id: loader_ >>>> source: "MyComponent.qml" >>>> } >>>> >>>> Binding >>>> { >>>> target: loader_.item >>>> property: 'model' >>>> value: myModel_ >>>> when: loader_.status == Loader.Ready >>>> } >>>> >>>> What I would like is the Loader call QQmlComponent::beginCreate(), then >>>> having a hook to init some property then the Loader can finish the >>>> component QQmlComponent::completeCreate(). This way I was able to make it >>>> work, but having a custom component for that is a bit annoying. >>>> >>>> Loader >>>> { >>>> source: "MyComponent.qml" >>>> onInitProperty: // signal emit with component object returned by >>>> beginCreate(), >>>> { >>>> object.model = Qt.binding(function(){ return myModel_; }); >>>> ... >>>> } >>>> } >>>> >>>> That seem clean and would avoid the problems to have object into bad >>>> state for a brief moment. >>>> >>>> Jerome >>>> >>>> On Fri, Apr 1, 2016 at 12:04 AM, Shantanu Tushar <shaan...@gmail.com> >>>> wrote: >>>> >>>>> Hi, >>>>> >>>>> Have you tried using the QML Binding Type? >>>>> <http://doc.qt.io/qt-5/qml-qtqml-binding.html> >>>>> http://doc.qt.io/qt-5/qml-qtqml-binding.html >>>>> >>>>> On Thu, Mar 24, 2016 at 11:11 PM, Jérôme Godbout < >>>>> <jer...@bodycad.com>jer...@bodycad.com> wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> I was wondering if I am the only one who found the initial property >>>>>> of a source based Loader Item a bit annoying. inline sourceComponent with >>>>>> Component {} declaration are well ok on the other hand. I'm explaining >>>>>> myself, when using a loader you have 2 choice to set the initial binding >>>>>> on >>>>>> created item: >>>>>> >>>>>> 1- On item changed set the binding >>>>>> >>>>>> *Loader* >>>>>> *{* >>>>>> * source: externalObj.getSrc() // return something like "myItem.qml"* >>>>>> * onItemChanged:* >>>>>> * {* >>>>>> * if(!item) return;* >>>>>> * item.myprop = Qt.binding(function(){ return myExternalProperty; >>>>>> })* >>>>>> * }* >>>>>> *}* >>>>>> >>>>>> 2- use the setSource() function instead of the source directly >>>>>> >>>>>> *Loader* >>>>>> *{* >>>>>> * property url myDummySrc: externalObj.getSrc()* >>>>>> * onMyDummySrcChanged:* >>>>>> * {* >>>>>> * setSource(myDummySrc, { 'myprop': Qt.binding(function(){ return >>>>>> myExternalProperty; }) });* >>>>>> * }* >>>>>> *}* >>>>>> >>>>>> This is rather annoying and ugly. Number 1 is also having the problem >>>>>> where *myItem.qml* must be able to handle *myprop *to have a default >>>>>> value or being empty without output a lots of console error. Number 2 >>>>>> work >>>>>> well and is the solution I find myself writing often. I was wondering if >>>>>> a >>>>>> Loader that support a dictionary of initial property when source changed >>>>>> would be nice: >>>>>> >>>>>> *Loader* >>>>>> *{* >>>>>> * source: externalObj.getSrc()* >>>>>> * initialProperties: { 'myprop': Qt.binding(function(){ return >>>>>> myExternalProperty; }) }* >>>>>> *}* >>>>>> >>>>>> What do you think? >>>>>> Jerome >>>>>> >>>>>> _______________________________________________ >>>>>> Interest mailing list >>>>>> Interest@qt-project.org >>>>>> http://lists.qt-project.org/mailman/listinfo/interest >>>>>> >>>>>> >>>>> >>>>> >>>>> -- >>>>> Shantanu Tushar (UTC +0530) >>>>> shantanu.io >>>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> Interest mailing >>>> listInterest@qt-project.orghttp://lists.qt-project.org/mailman/listinfo/interest >>>> >>>> >>>> >>>> _______________________________________________ >>>> Interest mailing list >>>> Interest@qt-project.org >>>> http://lists.qt-project.org/mailman/listinfo/interest >>>> >>>> >>> >>> _______________________________________________ >>> Interest mailing list >>> Interest@qt-project.org >>> http://lists.qt-project.org/mailman/listinfo/interest >>> >>> >> >
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