I have a dynamic class that I have created
public dynamic class SiteZoneFileUploadVO
{
public var destination:String = "sitezone";
public var siteZoneId:uint;
public var fileType:String;
public var fileContents:String;
public function SiteZoneFileUploadVO()
{
}
}
when I try to iterate over this object's property names it only iterates the dynamically added properties.
parameters.dynVar= "value";
for(var name:String in parameters)
{
trace(name);
}
Even though the object has all the properties equal to a value (ive checked this in the debugger) the only property name that will be traced is dynVar.
How can I iterate over all the property names and not just the dynamically added ones?
You can use describeType() to get an XML with all methods and variables of your class and then filter out the properties you want to iterate over (e.g. all variables) and store them in an XMLList.
As the next step you would then iterate over the XMLList and use square bracket notation on your object to access the filtered properties by their names. However, you can only access public properties this way because describeType() won't look at private properties.
If you're running flex:
Looked at a few posts, ObjectUtil.toString was the most promising, then looked at the flex source code for it, it uses another method ObjectUtil.getClassInfo which is exactly what you need. If you just want property names:
ObjectUtil.getClassInfo(myClass).properties
returns an Array of QName objects, each has a localName property which will give you a string for each property name
Just use trace(ObjectUtil.toString(parameters)); That should give you your entire object.
Related
I'm trying to write to XML an object that has fields referencing multidimensional lists, but it doesn't work, in the XML file I see the field names but no values
this is my object:
#XmlRootElement
#XmlAccessorType(XmlAccessType.FIELD)
#XmlAccessorOrder(XmlAccessOrder.ALPHABETICAL)
public class DataHolder {
// some fields here
private List<ArrayList <Integer>> status = new ArrayList<ArrayList<Integer>>();
private List<ArrayList <Double>> balance = new ArrayList<ArrayList<Double>>();
private List<ArrayList<String>> date = new ArrayList<ArrayList<String>>();
}
I know I can wrap inner lists and have something like List<Object>
but I'd have to change a lot of supporting code for this, is there another option?
I ended up using lists of wrapped lists, thanks.
i am getting error "Object reference not set to an instance of an object." my is here,
public class UserProfession
{
public UserProfession()
{
}
public System.String[] Designation
{
get;
set;
}
}
then i am using it like,
UserProfession.Designation[0] =txt_Search.Text.ToString();
Error i mentioned you hopes for your suggestions .
-Thanks
When you make an assignment to an array property, like this:
UserProfession.Designation[0] =txt_Search.Text.ToString();
what you are actually doing is calling the get section for that property... not the set. This returns the object supported the property... the whole object, and not just the index. Index lookup does not happen until after the object is returned. Once you have that object, accessing an index works in the normal way.
You get this specific exception because you have the expression UserProfession.Designation that should return a reference to an array object, but because you never initialize the array there is nothing there when you then try to find reference the 0th element. At this point the framework discovers that the array (your "object reference") is "not set to an instance of an object"... which is just a fancy way of saying it's null.
In other words, you need to have an already existing array to hold the value you want to assign. That means doing something like this:
Designation = new String[10];
public String[] Designation
{
get;
set;
}
However, notice that we never used the set section? So you can simplify that further, like this:
Designation = new String[10];
public String[] Designation {get;private set;}
This will keep client code from completely swapping an entire array out from under your object, but otherwise will provide the full functionality of an array property. If you provide your own backing store for the array, you could even get rid of the setter entirely with no loss of functionality:
private string[] _designation = new string[10];
public string[] Designation {get {return _designation;} }
But let's add one more wrinkle: your desire to assign the to array before initializing it indicates to me that you likely don't really know how big it will be up front. If that's the case, you probably want a collection of some kind instead of an array. A generic List is a convenient and very compatible replacement for an array. That would look like this:
private List<string> _designation = new List<string>();
public List<string> Designation {get {return _designation;}}
You can still access items in that list by index, just like you would with an array. The only difference you need to worry about right now is how you add new items:
UserProfession.Designation.Add(txt_Search.Text);
Also notice that I removed the .ToString() call. Since your .Text property is almost certainly already a string, calling the .ToString() method is just silly.
You will have to initialize the object, before assigning the value. The initialization should be done just once. I have initialized the array size to ten. You can have your own values here. If you want to resize dynamically, you can use ArrayList
int length = 10;
UserProfession.Designation = new System.String[length];
UserProfession.Designation[0] =txt_Search.Text.ToString();
For more information: http://msdn.microsoft.com/en-us/library/aa287601(v=vs.71).aspx
it must initialize the value before we use because, currently, it is null.
you better add the initialization code in the constructor function.
I know an ItemRenderer is a ClassFactory and that you can use the newInstance method of ClassFactory to get an instance of the ItemRenderer. My question, however, is is it possible to use methods of the ItemRenderer without using ClassFactory.newInstance()?
In my case I can't use this newInstance method because it doesn't keep the state.
Is there any way I can do this? Thanks!
An ItemRenderer is a component, like any other. The itemRenderer property of a list based class has a value of a ClassFactory. If you have a reference to an instance of the itemRenderer component, you can call methods on it.
You cannot call a method on any component if an instance if that component instance has not been created yet. So to call a method on an itemRenderer without using ClassFactory.newInstance() you must manually create your own instance using the new keyword.
You might want to implement the ItemRenderer as smart as it is needed to recreate the state depending in the data being set. On the other hand, make sure that the data contains everything needed. You barely want to interact with the renderers in a different scope then the renderer itself.
If it should necessary, a DataGroup dispatches a RendererExistence event when a renderer is added.
private function newList():List {
const list:List = new List();
list.addEventListener(FlexEvent.INITIALIZE, list_initializeHandler);
return list;
}
private function list_initializeHandler(event:FlexEvent):void {
const listBase:ListBase = ListBase(event.target),
dataGroup:DataGroup = listBase.dataGroup;
dataGroup.addEventListener(RendererExistenceEvent.RENDERER_ADD, dataGroup_rendererAddHandler);
dataGroup.addEventListener(RendererExistenceEvent.RENDERER_REMOVE, dataGroup_rendererRemoveHandler);
}
private function dataGroup_rendererAddHandler(event:RendererExistenceEvent):void {
// renderer added
}
private function dataGroup_rendererRemoveHandler(event:RendererExistenceEvent):void {
// renderer removed
}
This is the way to go if you need to reference single item renderer instances.
Do you mean static functions and variables?
If you define a function (or variable, or const) as static, it is accessible via the class name, so you could define
class MyClass {
public static const className:String="MyClass.className (const)";
public static function getClassName():String {
return "MyClass.getClassName (function)";
}
}
trace(MyClass.className); //prints "MyClass.className (const)"
trace(MyClass.getClassName()); //prints MyClass.getClassName (function)
I have two classes in two separate libraries (one VB, one C#):
Public Class Item
...
Public Overridable ReadOnly Property TotalPrice() As String
Get
Return FormatCurrency(Price + SelectedOptionsTotal())
End Get
End Property
End Class
and
public class DerivedItem : Item {
...
public new Decimal TotalPrice
{
get { return Price + OptionsPrice; }
}
}
As you can see, the DerivedItem.TotalPrice shadows the Item.TotalPrice property. However, when trying to retrieve the DerivedItem.TotalPrice value, I'm still getting the base object's TotalPrice value.
Why is the DerivedItem's property not being returned?
EDIT
I've actually found the problem! I am getting the wrong value in the JSON string being returned via AJAX. It turns out that the TotalPrice is being returned correctly, it's just being overwritten by the shadowed property call being made later in the JSON string. My new question, then, is how to I prevent the shadowed property from being serialized?
(This question has been rescoped here)
It may depend on how you are instantiating the object.
For example:
DerivedItem i = new DerivedItem();
i.TotalPrice();
Will call the shadowed version.
However:
Item i = new DerivedItem();
i.TotalPrice();
Will actually call the base.
Here's a nice explanation.
Of course if at all possible I would avoid shadowing.... :-)
Are you referecing TotalPrice from a reference to the base type?
Item item = new DerivedItem;
string s = item.TotalPrice;
Does setting <NonSerialized()> attribute on the base class property work?
When sorting on a column in the GridView bound to an Enum, it sorts by the order of the Enum. I need it to sort by the string representation of the Enum. Here are the options I have seen, of which I like none of them.
Reorder the Enum in alphabetical order - Bad because now the presentation is relying on the Business and Data Access Layer to "pre-sort" the data.
Create a new object (datatable, new list, whatever) with myEnum.ToString() and bind this to the GridView - This one is not bad, but I would rather not.
In my search, check to see if the column sorted is an Enum, then sort by the string representation of the column - Do I have to say why this is bad?
Number 2 would be my favorite so far, but like I said, I don't like it.
More info just in case - I am binding a List of IWhatever to the grid, and 2 columns are enums that need to be sorted by strings. There are also guid-type, string, and decimal columns in the grid that need to be sorted.
Try to use ViewModels. Basically you create ViewModel Objects that contains your Model Object (your IWhatever). This ViewModel exposes then new Properties and Methods which are used in your View. In Your case you would expose a property with the string representation of your Enum. The advantage is, that you could do any transformation logic you want.
See MVVM Pattern. http://en.wikipedia.org/wiki/Model_View_ViewModel
EDIT: Little Example:
public class WhateverViewModel
{
public WhateverViewModel(IWhatever model)
{
this.model = model;
}
...
public string MyEnumView
{
get
{
return model.MyEnum.ToString();
}
}
public string MyEnumView2
{
get
{
switch(model.MyEnum)
{
case MyEnumType.A: return "Hello";
case MyEnumType.B: return "World";
}
}
}
}