I've been messing around with CM conventions trying to understand how they work but i haven't found a decent article somewhere explaining step-by-step how and why.
However I've found a few code snippets that i've been working with with some success.
In this case, however, i don't understand what is going on.
I'm trying to bind a NumericUpDown Value and Maximum to a corresponding ViewModel property. I was able to do it with the following code:
Value
ConventionManager.AddElementConvention<NumericUpDown>(NumericUpDown.ValueProperty, "Value", "ValueChanged");
Maximum
ConventionManager.AddElementConvention<NumericUpDown>(NumericUpDown.MaximumProperty, "Maximum", "MaximumChanged");
var baseBindProperties = ViewModelBinder.BindProperties;
ViewModelBinder.BindProperties =
(frameWorkElements, viewModels) =>
{
foreach (var frameworkElement in frameWorkElements)
{
var propertyName = frameworkElement.Name + "Max";
var property = viewModels.GetPropertyCaseInsensitive(propertyName);
if (property != null)
{
var convention = ConventionManager.GetElementConvention(typeof(NumericUpDown));
ConventionManager.SetBindingWithoutBindingOverwrite(
viewModels,
propertyName,
property,
frameworkElement,
convention,
convention.GetBindableProperty(frameworkElement));
}
}
return baseBindProperties(frameWorkElements, viewModels);
};
However, an here comes the weird part, i can only make one of them to work. That makes me believe that i'm doing some noob mistake somewhere. It almost seems i can only call AddElementConvention and therefor only the last call is executed.
I would appreciate either a help with this piece of code or a reference to some good documentation that could help me with it.
Best Regards
i found out somewhere that CM only allows one convention per item so that's the reason of this behavior...
However since items like ComboBox allows binding for multiple properties (SelectedItem, ItemSource and so on...) i'm not completed convinced...
Related
TLDR
I like to really focus on keeping business logic away from the view model / controller. I find this sometimes rather hard in Meteor. Maybe I'm missing the point but I am after one of two things really:
1) A really good document explaining at a really low level how reactive values are being used.
2) A package that somehow manages an object so that if any of the setters are altered, they notify all of the get functions that would change as a result.
Unfortunately I've not seen either.
My Example
I have a fair bit ob business logic sitting behind a dialog used to document a consultation. I might have an event that sets a change of state.
I'd like to do something like this in the event:
const cc = new ConsultationEditor();
cc.setChiefComplaint(event.target.value);
console.log(cc.data());
ConsultationDict.set("consEdit", cc.data() );
When the user has updated this value, I'd then like to show a number of fields, based on the change. For this I have a helper with the following:
fields: function(){
console.log("trying to get fields");
const obj = ConsultationDict.get('consEdit');
cc = new ConsultationEditor(obj);
return cc.getFields();
}
But unfortunately this does not work for me.
What is your ConsultationDict?
The way you describe it, you want it to be a ReactiveDict as in the official ReactiveDict package.
https://atmospherejs.com/meteor/reactive-dict
Check this tutorial for examples:
https://themeteorchef.com/snippets/reactive-dict-reactive-vars-and-session-variables/
If you really need more fine tuning in your reactivity, you can also set a dependency tracker tracker = new Tracker.Dependency, and then refer to it wherever you change a variable with tracker.changed() and where the data needs to be notified with tracker.depend() like this:
var favoriteFood = "apples";
var favoriteFoodDep = new Tracker.Dependency;
var getFavoriteFood = function () {
favoriteFoodDep.depend();
return favoriteFood;
};
var setFavoriteFood = function (newValue) {
favoriteFood = newValue;
favoriteFoodDep.changed();
};
getFavoriteFood();
See the full Tracker doc here:
https://github.com/meteor/meteor/wiki/Tracker-Manual
I also found this gist to be useful to build reactive objects:
https://gist.github.com/richsilv/7d66269aab3552449a4c
and for a ViewModel type of behavior, check out
https://viewmodel.meteor.com/
I hope this helps.
From time to time I have the requirement to bind a control property to based on data out of model A to another model B.
For example the syntax could look like this (but will not work):
text : "{B>/rootB/{A>someValue}/propertyB}"
I normally solve this problem by "misusing" an unused control property in combination with the format function. It would look like this:
tooltip : {
path : "A>someValue",
formatter : function(oValue) {
// do some checks on oValue
var path = "B>/rootB/"+oValue+"/propertyB";
this.bindProperty("text", path);
return undefined; // because tooltip is not used
}
The benefit of this, each time "A>someValue" will be changed the binding of "text" will be updated automatically.
It is also possible to do this in template code (like items aggregations).
But you may smell the code ;)
Any suggestions to make it cleaner?
As far as I know, there is no such possibility in UI5 (yet). I always use a formatter function as you already mentioned. I say not YET, because developers seem to be aware of this feature request: see on GitHub
BUT, you dont need to missuse a random control property! Just use the formatter to read the needed values from any model you have access to:
text : {
path : "A>someValue1",
formatter : function(oValue) {
// read model B to get someValue2 (based on someValue1)
var path = "B>/rootB/"+oValue+"/propertyB";
var B = getModel("someModel");
var someValue2 = B.getProperty(path);
return someValue2
}
i am trying to figure out if i can in anny way get the exact position for every character inside a textflow?, also I'm having trouble with the TLF documentation, is there anny documentation that shows more on how to work with it in actionscript rather than mxml, im looking to write my own component and perhaps not use richtexteditor if i don't need to.
Many thanks!
Edit: i finally think i figured out how to get each characters position in the textflow:
private function getCharPosition():void {
for (var i:int=0; i<=textController.flowComposer.numLines; i++) {
var textFlowLine:TextFlowLine = textController.flowComposer.findLineAtPosition(i);
var textLine:TextLine = textFlowLine.getTextLine();
trace('number of atoms in this line: ' + textline.atomCount);
for (var j:int=0; j<=textLine.atomCount; j++) {
try {
trace(textLine.getAtomBounds(j));
} catch (e:Error) {
trace('error');
}
}
}
}
This returns an error that's why i have try and cache, i have tried to change textLine.atomCount to -1 but that wont work either. Now i don't know what character exactly that i have the position for. Lots of figuring out yet...
You can use some of these steps which (among other things) allow to determine character's bounds.
What about your second question you can refer to the following documentation and/or some samples.
We need to be able to handle a "playable" (play/pause/seek) effect in which the nature of the effect cannot be determined at compile time.
The problem we are running into is resetting the target(s) state after the effect has completed. If we manually drag the seek slider back to the beginning, everything works fine. However, if we set the playheadTime of the composite effect back to 0, the effected targets retain their original value until the playheadTime gets to the correct position to effect the target.
Here is a simplified (as much as I could) test case with view source enabled:
http://www.openbaseinteractive.com/_tmp/PlayableEffectTest/
The problem is demonstrated if you let it play to the end, and then hit the play button to start it over.
What is the best way to go about manually resetting the target values given that the exact nature of the effect is unknown?
Many thanks for your time!
edit
I forgot to mention we are using Flex 4.5 preview release.
Have you tried:
effect.reverse()
More info
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/mx/effects/IEffect.html
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/mx/effects/IEffect.html#reverse()
Well it's a little kludgy, but I was able to accomplish this by calling some internal methods on the effect to capture the start values, then assigned those values to the targets on a reset.
import mx.core.mx_internal;
use namespace mx_internal;
private var _propertyChangesArray:Array;
protected function captureStartValues(effect:Object):void
{
effect.captureStartValues();
_propertyChangesArray = effect.propertyChangesArray;
}
protected function reset(effect:Object):void
{
for each(var change:PropertyChanges in _propertyChangesArray)
{
var target:Object = change.target;
for(var p:String in change.start)
{
if(target.hasOwnProperty(p))
{
var startVal:* = change.start[p];
var endVal:* = target[p];
if(!isNaN(startVal) && startVal != endVal)
{
target[p] = startVal;
}
}
}
}
effect.playheadTime = 0;
}
I don't know if this is the best way to accomplish this, but it seems to be working so far. I am absolutely open to suggestions for a better method.
Cheers!
I have a UI component that, for various reasons, I have to construct programatically. The component is a table of radio buttons grouped by column.
Right now, I'm constructing the column groups like so:
private function createGroupsForItemList(items: XMLList): void {
for each (var item: XML in items) {
var rbGroup: RadioButtonGroup = new RadioButtonGroup();
groups[item.#level.toString()] = rbGroup;
}
}
I'm trying to associate the RadioButton instances with the column groups like so:
private function createValueControl(item: XML): UIComponent {
var control: RadioButton = new RadioButton();
control.label = "";
control.group = groups[item.#level.toString()];
control.addEventListener(Event.SELECT, updateSelection);
return control;
}
I can see in the debugger that the control has an association to the group:
control.group == groups[item.#level.toString()]
However, I can see equally that the group does not know anything about the control:
group.radioButtons.length == 0
I imagine that this is because the setter for group in RadioButton is a dumb setter; all it does is copy to the variable, which doesn't do the magic that groupName does. However, I can't seem to find the value I should use to set the RadioButton.groupName property correctly.
So, in short, I'm stumped on how to get these bits to talk to each other. How do I do this?
-- EDIT --
It turns out that I can have the groups created and associated simply by setting the groupName property, but I can't get at the group to set up a selection listener; the group is NULL immediately after the setting process, which means that the second line below throws the Flex equivalent of an NPE:
control.groupName = groupNameForLevel(item);
control.group.addEventListener(Event.SELECT, updateSelection);
First instinct is that this issue has to do with invalidateDisplayList and when and how that is called. Of course, since issues related to that function are behind a number of Flex's quirks, I may just be scapegoating.
This is not the answer to your question per se, but it seems like it might actually work as an alternate solution.
RadioButtonGroups will initialize based on a IFlexDisplayObject. This means that you can do something like:
var c:HBox = new HBox();
var rbg:RadioButtonGroup = new RadioButtonGroup( c );
// do stuff with rbg.
c.addChild( new RadioButton() );
The problem is that it may not be the most practical answer, but it has the decided benefit of being a workable solution.
Setting groupName should work.
All I can suggest is to step through the group() getter of the RadioButton component and see where exactly it is failing. Are you programmatically creating the group too? If that's the case, maybe it isn't initialized fully yet.