i have the following 2 classes
class A {
var one:int;
}
class B extends A {
var two:int;
}
I now have an object of the class A but need to create and object of class B and set the additional parameters.
Does Flex allow child object creation given a parent object ?
note: there are lot of parameters in A so i don't want to copy individually each one.
Flex does allow multiple constructors, but it would take the form of copying each parameter in the constructor.
public class B extends A {
var two:int;
public function B(instanceA:A) {
this.one = instanceA.one;
//etc
}
}
Another approach could be to use ObjectUtil:
public class B extends A {
var two:int;
public function B(instanceA:A) {
var data = ObjectUtil.getClassInfo(instanceA);
for each (var prop in data.properties) {
this[prop] = instanceA[prop];
}
}
}
n.b. Check the excludes and options arguments of getClassInfo -- if there are properties that would cause problems to be processed in this way, you'll want to make sure to exclude them.
Related
I am a newbie to javafx, kotlin and obviously tornadofx.
Issue:
How to pass parameters to Fragment on every instance?
Lets say I have a table view layout as my fragment. Now this fragment is used at multiple places but with different datasets.
eg.
Adding a fragment in:
class SomeView : View() {
...
root += SomeViewFragment::class
}
class SomeAnotherView : View() {
...
root += SomeViewFragment::class
}
Declaring Fragment:
class SomeViewFragment : Fragment() {
...
tableview(someDataSetFromRestApiCall) {
...
}
}
How can I pass different someDataSetFromRestApiCall from SomeView and SomeAnotherView ?
Let's start with the most explicit way to pass data to Fragments. For this TableView example you could expose an observable list inside the Fragment and tie your TableView to this list. Then you can update that list from outside the Fragment and have your changes reflected in the fragment. For the example I created a simple data object with an observable property called SomeItem:
class SomeItem(name: String) {
val nameProperty = SimpleStringProperty(name)
var name by nameProperty
}
Now we can define the SomeViewFragment with an item property bound to the TableView:
class SomeViewFragment : Fragment() {
val items = FXCollections.observableArrayList<SomeItem>()
override val root = tableview(items) {
column("Name", SomeItem::nameProperty)
}
}
If you later update the items content, the changes will be reflected in the table:
class SomeView : View() {
override val root = stackpane {
this += find<SomeViewFragment>().apply {
items.setAll(SomeItem("Item A"), SomeItem("Item B"))
}
}
}
You can then do the same for SomeOtherView but with other data:
class SomeOtherView : View() {
override val root = stackpane {
this += find<SomeViewFragment>().apply {
items.setAll(SomeItem("Item B"), SomeItem("Item C"))
}
}
}
While this is easy to understand and very explicit, it creates a pretty strong coupling between your components. You might want to consider using scopes for this instead. We now have two options:
Use injection inside the scope
Let the scope contain the data
Use injection inside the scope
We will go with option 1 first, by injecting the data model. We first create a data model that can hold our items list:
class ItemsModel(val items: ObservableList<SomeItem>) : ViewModel()
Now we inject this ItemsModel into our Fragment and extract the items from that model:
class SomeViewFragment : Fragment() {
val model: ItemsModel by inject()
override val root = tableview(model.items) {
column("Name", SomeItem::nameProperty)
}
}
Lastly, we need to define a separate scope for the fragments in each view and prepare the data for that scope:
class SomeView : View() {
override val root = stackpane {
// Create the model and fill it with data
val model= ItemsModel(listOf(SomeItem("Item A"), SomeItem("Item B")).observable())
// Define a new scope and put the model into the scope
val fragmentScope = Scope()
setInScope(model, fragmentScope)
// Add the fragment for our created scope
this += find<SomeViewFragment>(fragmentScope)
}
}
Please not that the setInScope function used above will be available in TornadoFX 1.5.9. In the mean time you can use:
FX.getComponents(fragmentScope).put(ItemsModel::class, model)
Let the scope contain the data
Another option is to put data directly into the scope. Let's create an ItemsScope instead:
class ItemsScope(val items: ObservableList<SomeItem>) : Scope()
Now our fragment will expect to get an instance of SomeItemScope so we cast it and extract the data:
class SomeViewFragment : Fragment() {
override val scope = super.scope as ItemsScope
override val root = tableview(scope.items) {
column("Name", SomeItem::nameProperty)
}
}
The View needs to do less work now since we don't need the model:
class SomeView : View() {
override val root = stackpane {
// Create the scope and fill it with data
val itemsScope= ItemsScope(listOf(SomeItem("Item A"), SomeItem("Item B")).observable())
// Add the fragment for our created scope
this += find<SomeViewFragment>(itemsScope)
}
}
Passing parameters
EDIT: As a result of this question, we decided to include support for passing parameters with find and inject. From TornadoFX 1.5.9 you can therefore send the items list as a parameter like this:
class SomeView : View() {
override val root = stackpane {
val params = "items" to listOf(SomeItem("Item A"), SomeItem("Item B")).observable()
this += find<SomeViewFragment>(params)
}
}
The SomeViewFragment can now pick up these parameters and use them directly:
class SomeViewFragment : Fragment() {
val items: ObservableList<SomeItem> by param()
override val root = tableview(items) {
column("Name", SomeItem::nameProperty)
}
}
Please not that this involves an unchecked cast inside the Fragment.
Other options
You could also pass parameters and data over the EventBus, which will also be in the soon to be released TornadoFX 1.5.9. The EventBus also supports scopes which makes it easy to target your events.
Further reading
You can read more about Scopes, EventBus and ViewModel in the guide:
Scopes
EventBus
ViewModel and Validation
I've been trying to figure this out recently, and that's what I got:
You need create button which will switch your components
button {
text = "open fragment"
action {
val params = Pair("text", MySting("myText"))
replaceWith(find<MyFragment>(params))
}
}
On second components
class MyFragment : Fragment("Test") {
var data = SimpleStringProperty()
override val root = hbox {
setMinSize(600.0, 200.0)
label(data) {
addClass(Styles.heading)
}
}
override fun onDock() {
data.value = params["text"] as String
}
}
As a result, we get the parameters in the second component
I am trying to find a way to override a structuremap registry statement containing EnrichWith like so (here is the Registry class):
public class MyRegistry : Registry
{
public MyRegistry()
{
For(typeof(IMyList<int>)).EnrichWith(x => DecorateMyList(x)).Use(typeof(MyListA<int>));
For(typeof(IMyList<int>)).Use(typeof(MyListB<int>));
For<IMyList<string>>().Use<MyListA<string>>();
For<IMyList<string>>().Use<MyListB<string>>();
}
private object DecorateMyList(object o)
{
var genericParameters = o.GetType().GetGenericArguments();
var myListDecoratorType = typeof(MyListDecorator<>).MakeGenericType(genericParameters);
var decorated = Activator.CreateInstance(myListDecoratorType, new []{o});
return decorated;
}
}
public class MyRegistryUser
{
ObjectFactory.GetInstance<IMyList<string>>(); // Good: Returns an instance of MyListB<string> as expected
ObjectFactory.GetInstance<IMyList<int>>(); // Bad: Returns an instance of the decorator containing MyListB<int> - my second rule should have overridden the EnrichWith as well.
}
Am I right to think that there is a glitch in structure map or is there something I'm not seeing?
Thanks in advance
//Base.as
public class Base
{
private var _foo:String;
[Bindable]
public function set foo(value:String):void
{
_foo = value;
}
public function get foo():String
{
return _foo;
}
/*
Many many setter/getter, methods, events
*/
}
//Control.as
public class MyControl extends Group
{
public function MyControl()
{
}
}
//Window.as
public class MyWindow extends spark.components.Window
{
public function MyWindow()
{
}
}
//Module
public class MyModule extends spark.modules.Module
{
public function MyModule()
{
}
}
I want to expose (friendly) Base properties, methods and events on the other classes. Something like this:
var window:MyWindow = new MyWindow();
window.foo = 'Hello World!';
var module:MyModule = new MyModule();
module.foo = 'bar';
<namespace:MyControl foo="Hello World!"/>
I don't want define all the properties in each class because they are many and the same for all of them.
Ideally would define something like:
public class MyControl extends Group, Base
{
public function MyControl()
{
}
}
(I know it can't be done.)
Thanks!
UPDATE:
Thanks again!
Maybe this clarify more my need... On business layer I have a variable called processID (and businessID, operationID, localityID, etc.) what be passed to Window from Menu, and Window passes it to Module. On Module Container, I have a CustomComponent what query database using this variable as parameter. This applied for all (almost) Components on Module. These variables are defined as level business layer, then I define a Class to store and manage these variables (and some related methods operating with these variables using business logic), so I can make a standalone class (or library) for every environment to reusing my common components. The idea is... insert a new CustomComponent and set these variables via mxml, like this:
<custom:MyCustomComponent id="zzz" processID="{processID}" businessID="{businessID}"/>
Module has the business logic for set (o not) any of the variables.
Otherwise, I would have to implement different logic for the CustomComponent (and Module) for read parent's variables and define these variables only in MyWindow (using composite pattern).
You can get your answer from following link -
http://flexinonroids.wordpress.com/2009/05/27/flex-3-dynamically-loading-components-at-runtime/
http://thecomcor.blogspot.in/2007/11/adobe-flex-dynamically-loading-classes.html
Or you can follow below approach -
1) Create an Interface as base
2) Extend your class with interface
3) Load class at runtime with SWFLoader.loaderContext.applicationDomain.getDefinition method
Thanks,
Varun
You can place your classes that require friendly access in the same package as your Base class, and define private fields without any access modifier( it is equivalent to internal modifier).
Otherwise, you can define your namespace like that:
namespace my_internal;
and then define class members like that:
my_internal var _foo:String;
after that, those members will be hidden for all code, except for code that contains
use namespace my_internal;
You can read more here:
http://help.adobe.com/en_US/ActionScript/3.0_ProgrammingAS3/WS5b3ccc516d4fbf351e63e3d118a9b90204-7f9e.html#WS5b3ccc516d4fbf351e63e3d118a9b90204-7f91
However, using 'friend access' can be an evidence of bad design, so if I were you I'd think twice before defining namespaces.
Update:
pseudo-superclass 1:
package proxy
{
public class Simple1
{
public var x:int;
public var y:int;
}
}
pseudo-superclass 2:
package proxy
{
import mx.controls.Alert;
public class Simple2
{
public var name:String = 'noname';
public function doAlert():void{
Alert.show(name);
}
//not normal method to replace 'this' with proxy
Simple2.prototype.doCrossClass = function doCrossClass():void{
Alert.show(''+(Number(this['x'])+Number(this['y'])));
}
}
}
Code for testing the result (looks as what you are expecting?):
var mega:Mega = new Mega();
mega.x = 100;
mega.y = 200;
mega.name = 'Multiple inheritance';
mega.doAlert();
mega.doCrossClass(); //300
And now pseudo-subclass with multiple inheritance:
package proxy
{
import flash.utils.Proxy;
import flash.utils.flash_proxy;
public dynamic class Mega extends Proxy
{
public function Mega()
{
super();
}
public var superArray:Array = [new Simple1(), new Simple2()];
flash_proxy override function getProperty(name:*):*{
for each(var superClass:Object in superArray){
if( name in superClass){
return superClass[name];
}
}
throw new Error('no such property');
}
flash_proxy override function setProperty(name:*, value:*):void{
for each(var superClass:Object in superArray){
if( name in superClass){
superClass[name] = value;
return;
}
}
throw new Error('no such property');
}
flash_proxy override function callProperty(name:*, ...args):*{
for each(var superClass:Object in superArray){
if( name in superClass){
var f:Function = superClass[name] as Function;
return f.apply(this, args);
}
}
throw new Error('no such function');
}
}
}
You can also want to use javascript-like class construction(i.e. just using simple Object and assigning properties and functions to it in any combinations you want).
I have a base class called BaseEvent and several descendants classes:
public class BaseEvent {
// the some properties
// ...
}
[MapInheritance(MapInheritanceType.ParentTable)]
public class Film : BaseEvent {
// the some properties
// ...
}
[MapInheritance(MapInheritanceType.ParentTable)]
public class Concert : BaseEvent {
// the some properties
// ...
}
I have a code which create the BaseEvent instance at runtime:
BaseEvent event = new BaseEvent();
// assign values for a properties
// ...
baseEvent.XPObjectType = Database.XPObjectTypes.SingleOrDefault(
t => t.TypeName == "MyApp.Module.BO.Events.BaseEvent");
Now, this event will be shows in BaseEvent list view.
I want to do the following: when a user click Edit button then show in list view lookup field with all descendants types. And when user saves record change ObjectType to selected value.
How can I do this?
Thanks.
PS. this is asp.net app.
I'm not sure that your approach is correct for what you are trying to achieve. First, I'll answer the question you have asked, and afterwards I'll try to explain how the XAF already provides the functionality you are trying to achieve, namely how to choose which subclass of record to create from the user interface.
In order to create a property which allows the user to choose a Type within the application, you can declare a TypeConverter:
public class EventClassInfoTypeConverter : LocalizedClassInfoTypeConverter
{
public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
{
List<Type> values = new List<Type>();
foreach (ITypeInfo info in XafTypesInfo.Instance.PersistentTypes)
{
if ((info.IsVisible && info.IsPersistent) && (info.Type != null))
{
// select BaseEvent subclasses
if (info.Type.IsSubclassOf(typeof(BaseEvent)))
values.Add(info.Type);
}
}
values.Sort(this);
values.Insert(0, null);
return new TypeConverter.StandardValuesCollection(values);
}
}
And then your base event class would look like:
public class BaseEvent: XPObject
{
public BaseEvent(Session session)
: base(session)
{ }
private Type _EventType;
[TypeConverter(typeof(EventClassInfoTypeConverter))]
public Type EventType
{
get
{
return _EventType;
}
set
{
SetPropertyValue("EventType", ref _EventType, value);
}
}
}
However, I suspect this is not the functionality you require. Modifying the value of the property will NOT change the base type of the record. That is, you will end up with a record of type BaseEvent which has a property Type equal to 'Concert' or 'Film'.
XAF already provides a mechanism for selecting the type of record to create. In your scenario, you will find that the New button is a dropdown with your different subclasses as options:
Therefore you do not need to create a 'type' property within your object. If you need a column to show the type of event in the list view, you can declare a property as follows
[PersistentAlias("XPObjectType.Name")]
public string EventType
{
get
{
return base.ClassInfo.ClassType.Name;
}
}
I have a bunch of variables in a class. There are situations when I want to set then to null/ "temp" etc as per a well defined logic. The challenge is to list out the variables at multiple places- tedious and error-prone.
classname.speed=NaN
classname.speedtype="not_set"
classname.distance=NaN
classname.distancetype="not_set"
Ideally, would prefer a way to refer to these variables programatically and set something like
"for all class variables- if variable ends in type, set as "not_set"; for other variables set as NaN
How can I achieve this? Any pointers will help
The simplest approach would be just write function to clear them all.
If you want something more automatic, it will requre efforts - look at introspection api. Basically, you call describeType on your class and it returns XML description. All variables will be listed there, along with other info. Then you can parse returned XML and set all variables to needed value, accessing them dynamically with square bracket syntax:
var myClass:MyClass = new MyClass();
myClass["varName"] = "new value";
It can be achieved through Inheritance i.e. implementing interface or extending class
which contains common fields
public class MyClass
{
public a:String = null;
public b:String = null;
public function MyClass()
{
}
}
which contains common var and Child Class could be
public class MyClassChild extends MyClass
{
public var c:String = null;
public function MyClassChild()
{
super();
this.a ="";
this.b ="";
}
}
and you can cast or use for each loop to set values
var temp:MyClassChild = new MyClassChild ();
MyClass(temp).a = "Hello World";
Hopes that helps