Actionscript 3 :: Flex Data Binding Through A Refenced Property?
Jun 8, 2011
class A: with a property "data:ArrayCollection". It's my data source (data provider) and has bitmaps.
class B: has an instance of A (called "Ainst") and calls the following method: C.init( Ainst.data). To pass the data provider to Object C.
class C: has a reference of the data provider "data" (because of "init" method). It shows the arrayCollection into Images as: Image.source = data.getItemAt(0).
But C never updates its images, that is, data binding doesn't work with this scheme. I've put [Bindable] meta-tag in all properties and even classes.
Lately i discovered MATE (for Flex development) and was wondering: how do i bind a property in a view (actually a navigatorcontent component) to another property in a class so that they stay in synchronization (meaning that whenever the property in the class changes the property in the view also changes).
So if we have a view called Target.mxml and a property targertProp how do we bind it to the class called SourceClass with property SourceProp?
If user change the value of the TextInput, then click refresh button to retrieve the data model from backend again, the GUI value will not change back. Re-binding not happen, Since the value of data model not changed, no propertyChanged event fired.In this case, I must Programmatically set the model value to the GUI after data refreshing done.I know bi-directional binding can solve this problem(when user change value on GUI, set the new value to data model immediately). But sometimes I cannot use bi-directional binding, for example, the data model is a int, but user input a non-int value, I cannot set the value to data model. So the value in data model do not change, when refresh data, rebinding still not happen.
This will make the data binding useless. How to resolve this?I put pseudo-code here for now, I will put real code later:1. retrieve a data model from server, via blazeds or something else.2. bind the model to a TextInput on GUI.3. user change the TextInput text.4. User click a refresh button, triger retrieve the model value again.5. Now since the model value do not change, no PropertyChanged event fired.6. GUI value still is the user's input, not the value from the model. can clear the model value before set the velue back, make re-binding happen.(but sometimes you do not know how to clean the model value, take int for example, you may do not know the original value and happen set the same value). Or I can manually set the model value to GUI. But both are not good looking.
I am using Flex to create a small form. All I have at the moment is a List component, that I want to populate with a list of font names.I am getting the fonts using Font.enumerateFonts(true);. This returns an array of flash.text.Font objects.
The Font objects have a fontName property that is a String of that fonts name.My problem is that I can't figure out how to bind the List's dataProvider to the fontName property of each of the Font objects in the Array.Is there a way to do this just with binding? and not creating a new array of Strings by looping through the Font objects?
I am trying to: 1) create a dynamic property 2) bind that property to a label This works great for "sealed properties", but for dynamic properties there doesn't appear to be any event triggered. Are dynamic properties implicityly not bindable?
var myObj:MyType = new MyType(); // MyType is dynamic myObj["myDynamicPropertyName"] = "initialized"; BindingUtils.bindProperty(myLabel, "data", myObj, repeatedLabel.name); // myLabel now displays "initialized" myObj["myDynamicPropertyName"] = "changed"; // myLabel still displays "initialized", it should say "changed" !!!
Is it possible to set a percentage value for the width property of an UIComponent defined in MXML using data binding?
What I try to achieve is something like this (which doesn't work):
<s:Button width="{buttonWidth}%"/>
I know that using percentage for width or height properties in MXML is kind of a hack in the Flex SDK, since they're supposed to accept numerical values only, but since percentWidth and percentHeight aren't available in MXML, I'm pretty stuck =/
I would really like to avoid using code to do such a simple thing, in order to keep my code as clear and readable as posible.
first one shows playheadtime of videodisplay and another is also used for same purpose. the difference is that when we are in add mode(decided from a flag variable) both should show current playheadtime using binding. but when we are in edit mode(again decided from flag) the latter label should remain static, to be more specific, the value retrived from database.how can I do that using actionscript. I tried ChangeWathcer but I found it a bit tricky. Is there any other simpler way or am I missing something. following is my code.
private function init():void { if (queFlag == 'a')
I'm having some troubles with binding data. I have an application that contains a viewstack of components. Let's say I have comp1, comp2 and comp3 inside the viewstack. Each component, has its own data class --> comp1Data.as, comp2Data.as and comp3Data.as. All values in each component are binded to the corresponding data in it's data object.
A click in a control in comp1 leads to comp3, the same goes for comp2. Clicking a control in comp2 leads to comp3. When going from comp1 to comp3, comp3Data.as is initialized and and comp3 displays the binded values. When going from comp2 to comp3, comp3Data.as is also initialized but the binded values are not displayed...
I'd like to add a derived property to flex:[code]However, derived won't update when I change a or b.Is there a better (faster) way to make derived update than giving a and b setter methods which invalidate it?added keyword "get".This makes more sense now, I hope.
I need to bind a property to an edit control and have the control write its value back to the same property. The problem is, I'm setting the source value before the control is created:
<mx:Panel> <mx:Script> <![CDATA[ [Bindable] public var editedDocument: XML;
But I get a warning from Flex that the binding wouldn't work that way and it doesn't. It works the first time I load up the component but every time I change findFriendsPaginationElement it doesn't reflect on the component. Do you know how I can go about doing this? (making changing a value in the binding variable changes the status of an element inside a component?)
I'm binding two AutoCompleteModified objects to one another; meaning you type in one and it selects the correct object in the other. It works fine when I define it in MXML: However, a user can add a new row to a Grid and then I set up the binding and objects via actionscript and it gives an 'undefined' error: ChangeWatcher line 427/wrapHandler.
var innerHBox:HBox = new HBox(); var dtc_acm:AutoCompleteModified = new AutoCompleteModified(); dtc_acm.dataProvider = data2; dtc_acm.labelField = 'id'; var cp_acm:AutoCompleteModified = new AutoCompleteModified(); [Code] .....
If I only keep it 1-way binding then it works fine. But both throw this error. Is there something about not only doing it 2-way in actionscript, but adding components that aren't on the stage yet?
But the ComboBoxes are being created dynamically with AS3, everything is working except I cant bind the second ComboBox dataProvider to be the XMLList in the first ComboBox's selectedItem.
In Flex 3, I've created a ComboBox within an MXML component similar to the following:
<mx:ComboBox id="comboBox" dataProvider="{_choices}" /> <mx:Script> <![CDATA[ import mx.collections.ArrayCollection; // etc... public function get choices():ArrayCollection { return _choices; } [Code] .....
In the parent MXML application, I'm modifying the contents of the choices property: myComponentId.choices.removeAll(); myComponentId.choices.addItem({data: "NY", label: "New York"}); myComponentId.choices.addItem({data: "CA", label: "California"}); // etc...
The binding is working in that the ComboBox is automatically picking up the new contents added at runtime, however it is not adjusting its width. The initial width of the ComboBox is wide enough only to show the initial item "All" declared in the component. However, I want and would have expected the ComboBox to re-size automatically during binding to be able to show "California", but it isn't. How can I get the ComboBox to update its width after I have added new wider labels to its dataProvider?
I have a main.mxml application that lays out my application, it contains a "browse and upload" button. And contains an image to view the users uploaded image like so:
<mx:Application <mx:Script> <![CDATA[
[Code].....
In my myModel class I have a img_scld_bm that the browseAndUpload() function draws into after scaling it.
My intent is that my mx:Image will display the image. As shown here I'm assigning the image source="mymodel.img_scld_bm", this ends up just showing a broken image icon.
I also tried data binding, where in my myModel class I have [Bindable] var img_scld_bm. And then tried setting my mx:Image source="{myModel.img_scld_bm}" .. that didn't seem to do anything either. All this compiles fine, no warnings. I think in this case, I'm not setting a trigger or propertyChange event to update the binding?
how to correctly bind an mx:Image source to some bitmap?
How do you set the selectedColor of a colorpicker when you bind data from a database? I have a bindable variable, objProject, with a field called color and it has a color code such as #ff00ff in it. I want to set the selectedColor. I tried to cast the color as a uint, but no joy.
objProject = cmbProject.selectedItem; c = uint(objProject.color); <mx:ColorPicker id="graphColor" x="17" y="219" width="128" height="40" selectedColor="{c}" editable="true" /> I did try selectedColor="{objProject.color}" and that didn't work either.
i'm using flash builder 4..i want to ask something..how to binding data to custom list component in flex??...i already try binding data from webservice to standard datagrid component in flex, and it's work perfectly...this is my code for binding to datagrid..
I'm trying to extend ButtonBarButton to include an additional label that shows the number of updates for the respective box in a viewstack (which is the tabbar's dataProvider).
I can get the additional label (named indicatorLabel) to read an initial value from data, but I can't get it to update automatically like the actual "label" attribute. My understanding was that you could bind to the data object, but that doesn't appear to be the case.
Is there some way in Flex where I can tell when all of the data has finished binding to my AdvancedDataGrid? I have a bunch of label functions that run and I need to a busy cursor while the grid gets populated. I then want to remove it when it's all done. And also fire another event.
I have a flex datagrid. it is bound to an array collection. if the user sorts on column X it works fine. then, if the user causes the array collection to change, the datagrid forgets that it was sorted on column X.what do I need to do to preserve this sort preference so that the new array data will appear sorted by column X?
I have a main mxml file (flex4) and want to pass a parameter (user_name) to a component in a directory called components. When I run the program, the user_name is NOT being sent from the main to the component file. (Interestingly, if you make the component visible, you can see the parameter has been passed).
I have hacked much larger files down to get the following two files: Main <?xml version="1.0" encoding="utf-8"?> <s:Application xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600" [Code] .....
Assume i have a custom actionscript class. [code]...
Suppose also that i have a different class, that changes a second variable, which has the metadatatag [Bindable]. What methods and events do i have to implement in either of these classes, to make myVariable change, whenever the other is changend?
In my case, some user interaction produces new values for the bindable variables "someDataProvider", and "someSelectedItem". However, when flex renders the DropDownList, the control's selected value is empty.
The reason for this is that the DropDownList's "selectedItem" property gets bound before the "dataProvider" property. The "dataProvider" needs to be bound first for "selectedItem" to be valid, this is because the new "selectedItem" points into the new "dataProvider".
what is the best practice for updating bindable properties in a specific order? I've come up with a few ways (e.g. using a valueCommit handler), but I wanted to see what the community had to say.
I am migrating an application from Flex 3 to Flex 4. In some cases there are popup windows of which the width and height is bound to the application width and height.
And I want to bind these values to textBoxes, so that when user types information to the textBoxes it is populated in the class too. Is Flex 3 bidirectional so that marking the class with [Bindable] I can bind the values to a textbox for example?This is my mxml file in which I try to bind the class:
I've been reading up on the Cairngorm architecture that Adobe recommends as best practice for devevloping RIA's in Flex.http:[url].....I recently purchased Flash CS3 and want to find a way to implement Cairngorm in my upcomming RIAs that will be built in Flash instead of Flex. I've created my own version of Cairngorm that uses almost all of the features and classes described in the Cairngorm architecture.
The biggest challenge for developing a Cairngorm architecture in Flash is that the architecturerelies heavily on Flex data binding to update the view when there are changes in the model. As far as I can find, there are no such capabilities built into AS3. This leaves me with a few not-so-desirable options.I could write my own data binding classes, or try to migrate the data binding classes from Flex.
each view class that can respond to changes in the model implements an "IBinded" interface that contains one function called modelUpdated. These classes register with a 'bind list' when they are instantiated, and any command that causes a change in the model also calls a function cycles through each registered view class, calling the 'modelUpdated' function to signify that the model has updated.This is a reasonable solution for a very simple application with very little model data, but as the application increases in complexity, it does not scale, because there is no way for a view class that is binded to an object in the model to know whether or not that object has changed - instead, EVERY view class that responds to changes in the model must check the current value of whatever objects they bind to and see if there has been an update.
