protected var categoryXML:XML;
protected var categoryArr:ArrayCollection;
protected var categoryList:IList;
for (var i:int=0;i<getLength(categoryXML.category);i++) {
trace(categoryXML.category[i].name);
categoryArr[i] = categoryXML.category[i].name;
}
I'm having trouble with this bit of code...
The trace here works great, and I get the response I expect, but when I try to add it to the categoryArr variable, I get yelled at and told it's null.
What could cause the difference here?
Thanks!
did you try to create your ArrayCollection : categoryArr = new ArrayCollection(); ?
So, if you are getting that there is a null reference at that line, it is because categoryArr is probably null. You need to initialize it, like #www0x0k suggested.
I will also suggest that you probably don't want to use indexes in this way. It assumes too much about the length of the particular ArrayCollection without any bounds checking. Consider code like this instead:
categoryArr = new ArrayCollection();
for each(var category in categoryXML.category) {
trace(category.name);
categoryArr.addItem(category.name);
}
Related
I have an AdvancedDataGrid that relies on a HierarchicalCollectionView as it's dataProvider. What I'd like to do is sort the data when it is first loaded, but then disable the sort so that anything that is added after the initial load doesn't cause the grid to auto-sort again. I tried something like this:
this._myDataProvider = new HierarchicalCollectionView(
new HierarchicalData(this._model.rootTasks));
var mySort:Sort = new Sort();
mySort.fields = [new SortField("startDate")];
this._tasksDataProvider.sort = taskSorting;
this._tasksDataProvider.refresh();
this._tasksDataProvider.sort = null;
But setting the sort to null just leaves the data unsorted. I guess what I'm asking is: how can I sort the underlying hierarchical data since it seems setting the sort property will keep it dynamically sorting. Thanks for any help you can provide.
Personally, I would change the sort order when you're getting the data. Either it's done on the server side or when you parse the data (ie. in your model). You can do a one time sort using Array with sortOn.
you can
1. sort the original data with sort function,
2. clone content and put it to a new collection with no sort (be careful do and make a manual clone),
3. just use the new data collection.
I had the same kind of problem until I realized that the sorting with Sort object does not change the "physical" ordering of the items within the Collection, so when you remove the Sort, the next refresh reverts the view to the actual "physical" ordering.
Similarily as stated above, I solved by it by cloning the sub-collections into sorted order this way:
public static function buildPositionSort():Sort
{
var dataSortField:SortField = new SortField();
dataSortField.name = "position";
dataSortField.numeric = true;
dataSortField.descending = false;
var sort:Sort = new Sort();
sort.fields = [ dataSortField ];
return sort;
}
/**
* This method is used to create a clone of ArrayCollection, because sorting does not
* actually change the physical ordering of the items.
*/
public static function createSortedArrayCollectionCopy(source:ArrayCollection):ArrayCollection
{
var target:ArrayCollection = new ArrayCollection();
source.sort = buildPositionSort();
source.refresh();
for each (var item:Object in source)
{
if (item.children != null) item.children = createSortedArrayCollectionCopy(item.children);
target.addItem(item);
}
return target;
}
private var MealsListResult:ArrayList = new ArrayList;
protected var _data:resultData = new resultData;
private function resultHandler():void
{
var Meals:Array = _data.Meals;
MealsListResult = _data.Meals as ArrayList;
MealDataGrid.dataProvider = Meals;
MealListView.dataProvider = MealsListResult;
}
Should this be working? the MealDataGrid is populating based on the array, but I am debugging and MealsListResult is null. but _data.Meals is not and I dunno if I'm missing something simple.
I can get it to work by doing it like: var MealsListResult2:ArrayList = new ArrayList(Meals); but I feel as though the first method should be working as well!
(there's mxml list and datagrid and such not shown here of course)
if _data.Meals is its runtime type is an array then _data.Meals as ArrayCollection will failed. but, new ArrayCollection(_data.Meals as Array) will working fine.
CMIIW
i guess your problem is you can't use single object as 2 or more different ui dataprovider.
try to use
MealDataGrid.dataProvider = _data.Meals;
MealListView.dataProvider = ObjectUtils.clone(_data.Meals);
UPDATE:
sorry i miss readed, i though it was ArrayColletion. but all you need to do is the same like ArrayCollection
The situation is simple. I have a datagrid that gets its data from a webservice.
When data from the webservice is retrived it calls the following function:
private function onListReg():void
{
arrRegOld = WSAutoreg.list.lastResult as ArrayCollection;
arrReg = WSAutoreg.list.lastResult as ArrayCollection;
dgReg.dataProvider = autoreglist;
}
dgReg is the Datagrid. the arr variables are ArrayCollections defined like so:
private var arrRegOld:ArrayCollection = new ArrayCollection;
[Bindable]
private var arrReg:ArrayCollection = new ArrayCollection;
The intent is when I hit a update button, it compares arrRegOld with arrReg and see if any values have changes. The problem is whenever I change values on the Datagrid it changes on both the dataProvider and on both ArrayCollections.
Does anyone know why is this happening? What should I do so that the binding applies only to one ArrayCollection?
Appreciate any tip.
- Mike
Your lists are sharing the same objects, if you modify the first element from arrReg you will see the modification also in arrRegOld - it is not related to binding. You need to clone the objects. You have several choices:
a) Implement a clone method for your objects (recommended)
b) Use a generic method like this one:
private function clone(source:Object):*
{
var array:ByteArray=new ByteArray();
array.writeObject(source);
array.position=0;
return(array.readObject());
}
and call arrRegOld = clone (arrReg); after arrReg = WSAutoreg.list.lastResult as ArrayCollection;
OK I am looping through the properties in an object like so:
private var _propsList:Object = {'Type':'product_type'
,'Kind':'product_type_sub'
,'Stone':'primary_stone'
,'Stone Color':'primary_stone_sub'
,'Metal':'metal_type'
,'Brand':'product_brand'};
for(key in _propsList)
{
val = _propsList[key];
trace(key +" = "+ val);
}
I am expecting the first trace to be Type = property_type since that is the first one defined in the array, however it is coming up random everytime. I guess this is because my keys are strings and not integers, however is there a way to specify the order it loops through them?
Thanks!!
You can't rely on for (v in someObject) ... to return things in a predictable order, no.
Depending on your specific situation, you could just use an array to hold the keys, and just iterate through that:
private var keys:Array = ["Type", "Kind", "Stone", "Stone Color", "Metal", "Brand"];
private function iterate():void
{
for each (var k:String in keys)
{
trace(_propsList[k]);
}
}
Maybe a bit obvious or non-elegant, but it'd get the job done. :)
you could hack it by classing-out your "_propsList" object creating an array inside of the newly created PropsList class that references the properties in order. At that point, you could run a FOR loop on the array and get your properties in order.
OR, you could have a function inside that new class that would return an Array of those properties. like this:
public function getProps():Array {
return [myPropertyOne, myPropertyTwo, myPropertyThree];
}
In general, I think this is a case where you shouldn't depend on a particular behavior from the framework/language you are using. This type of behavior is generally poorly documented and can change from version to version.
If you really need a specific retrieval order, I would create a wrapper class as jevinkones suggested above. Maybe there's even a utility class in the framework somewhere to accomplish this (Dictionary, etc.?)
HTH,
Karthik
I found this link that gives some background:
Subtle Change in for..in Loops for ActionScript 3
This question is actually a dup of this one.
How about using an array representation like this:
var _propsList:Array = [
['Type', 'product_type'],
['Kind', 'product_type_sub'],
['Stone', 'primary_stone'],
['Stone Color', 'primary_stone_sub'],
['Metal', 'metal_type'],
['Brand', 'product_brand']
];
for(var i in _propsList) {
var elem = _propsList[i];
var key = elem[0];
var val = elem[1]
}
In a Flex application I am trying to turn an Object into a QueryString such as name1=value1&name2=value2... But I am having trouble getting the names of the Objects children. How do I enumerate the names instead of the values?
Thanks
I'm guessing you're doing a for each(in) loop. Just do a normal for(in) loop and you'll get the names instead of the values:
for(var name:String in obj) {
var value:* = obj[name];
// do whatever you need
}
Ok, first off, if you need that query string to actually query a server, you don't really need to get it yourself as this code will query the server for you
protected function callSerivce():void
{
var o:Object = new Object();
o.action = "loadBogusData";
o.val1 = "dsadasd";
service.send(o);
}
<mx:HTTPService id="service" url="http://www.somewhere.com/file.php" method="GET" showBusyCursor="true"/>
Will make a call to the server like this: http://www.somewhere.com/file.php?action=loadBogusData&val1=dsadasd
But in case you really want to analyze the object by hand, try using ObjectUtil.getClassInfo, it returns a lot of information including all the fields (read more on LiveDocs).