Where's convertWorldToField method? - blackberry

In Class net.rim.device.api.lbs.MapField
There's a method convertWorldToField, which is quite useful.
After API upgrading new Map Class has been moved to:
net.rim.device.api.lbs.maps.ui.MapField
But method convertWorldToField disappeared, where is the method in new API ???

In the new set of classes, you don't need to convert from world to field to add something to the map. Instead, each item you add (extending Mappable) knows where to draw itself. This is how you create a location:
MapLocation ml = new MapLocation( 43.47751, -80.54817, "label", null );
MapDataModel model = map.getModel();
model.add(ml, "tag");
To check if something is or not visible you can use the methods in MapDataModel class.

Related

What is best way to update domain class object with large number of variables

Suppose I have Employee domain class, I want to create object of domain class from params map coming from UI side.
I can create object in two ways as follows
Normal way
Employee employee = new Employee(name: params.name, rollNo:
params.rollNo)
and so on. If domain class has 20 variables, then we need to write all variables in above constructor.
Following is best way to create object
Employee employee = new Employee(params)
Above constructor will populate object with matching params. Right.
Now my question comes here.
If suppose I have existing domain class object fetched from DB, Now I want to update this object from params map coming from UI.
What is best way to do this (like we do in above second option).
I think it is best to use command objects and bind it to the Employee.
here is sample pseudo code:
class EmployeeMgmtController {
def editEmp(EmployeeCmd cmd){
Employee editEmp = Employee.get(1)
editEmp.properties = cmd
editEmp.save()
}
}
class EmployeeCmd{
String id
static constraints = {
id blank:false,nullable:false
}
}
or,
you if your on controller, and still want to use params (and exclude any fields that you don't want to bind):
bindData(editEmp, params, [exclude:['firstName', 'lastName']])
If you want to achieve that in a service class, make your service implement grails.web.databinding.DataBinder then use the bindData method as demonstrated below.
import grails.web.databinding.DataBinder
class MyAwesomeService implements DataBinder {
/**
* Updates the given instance of a domain class to have attribute values specified
* in "newData" map.
*/
MyDomain updateMyDomainAttributes(MyDomain myDomianInstance, Map newData) {
bindData(myDomianInstance, newData)
myDomianInstance.save(flush: true)
}
}

Laravel 4: how to inject another class in a eloquent model

I'm trying to use the built-in laravel's Ioc container to inject a PageManager class inside a Page model and I'm a little lost.
What I'm trying to achieve is something like that:
class Pages extends Eloquent {
public function __construct(PagesManagerInterface $manager, array $attributes = array())
{
parent::__construct($attributes);
$this->manager = new $manager;
}
public function saveToDisk()
{
$this->manager->writeToFile();
}
But I obtain this error:
ErrorException: Argument 1 passed to Pages::__construct() must be an instance of PagesManagerInterface, none given.
I tried to add this in app/start/global.php:
App::bind('Pages',function(){
return new Pages(new PagesManager);
});
But is seems ignored by the framework, and also i don't know how to insert the $attribute array into this declaration.
I'm a little lost so any help is appreciated!
It's not a good idea to overload a model's constructor because new instances can be spawned behind the scenes through various methods, like Model::find().
When that happens, the dependencies you're asking for in your custom constructor aren't being passed in because the Model class isn't aware of them. So, you get that error message.
See the find() method here: http://laravel.com/api/source-class-Illuminate.Database.Eloquent.Model.html#380-397
See this post by Jason Lewis: http://forums.laravel.io/viewtopic.php?pid=47124#p47124
I think that what you need is:
App::bind('PagesManagerInterface',function(){
return new Pages(new PagesManager);
});
This tells Laravel to inject a new Page object everytime it needs an instance of your PagesManagerInterface wich wasn't passed while creating the model.
In Laravel you can use the IoC Container:
public function saveToDisk(){
$managerObject = app()->make('path\to\class\PagesManagerInterface');
$managerObject->writeToFile();
}

How to print a list of objects in a Velocity template?

This is a pretty basic problem and I'm pretty sure I'm doing something wrong or making some assumption. Here goes.
I'm writing a Jira plugin, which uses the Velocity template system. I have a list of ResultRow objects where ResultRow is a class with a single member variable: String key:
public class ResultRow {
public String key;
}
I have a list of these ResultRows:
List<ResultRow> rows = new ArrayList<ResultRow>();
ResultRow row = new ResultRow();
row.key = "foo";
rows.add(foo);
Map<String, Object> velocityParams = new HashMap<String, Object>();
velocityParams.put("rows", rows);
return descriptor.getHtml("view", velocityParams);
and I am trying to list these rows in a template with the following:
#foreach ($row in $rows)
<tr><td>$row.key</td></tr>
#end
I want the output to be: foo. Maddeningly, the template system simply prints the literal string "$row.key" instead of the contents of key. To verify that "$row" is indeed an object, I used the template:
#foreach ($row in $rows)
<tr><td>$row</td></tr>
#end
and the result was as expected: com.domain.jira.ResultRow#7933f2c6.
I think maybe I'm missing some requirement for the class. Does it need to be defined in some special way to suggest to Velocity that certain members are usable in templates? Does Jira use some special funky version of Velocity that only works with certain objects?
I guess the answer is you cannot do what I was trying to do. You can call member methods but you can't access member variables, which means you'll need to add getters to your class. (Could've sworn I tried that. Ah well.)
Velocity does not expose fields, only methods. There are ways to change that:
You can create your own Uberspect class that allows access to public fields.
You can wrap the instance with a modified version of Velocity's FieldMethodizer that gives access to non-static fields.
You can add and use an instance of a "tool" class to your context, such as a subclass of VelocityTool's ClassTool.

ASP.NET MVC Issue with Using Reflection Created Objects with the Default Model Binder

I am having a weird issue in ASP.NET MVC with objects not being updated with UpdateModel when passed a formCollection. UpdateModel does not appear to be working properly when the object being updated is created through reflection.
Scenario: I have an application which has approximately 50 lookup tables--each of which includes exactly the same schema including typical fields like id, title, description, isactive, and createdon. Rather than build 50 views, I wanted to have a single view which could display the data from all of the lookup tables. I created an Interface called IReferenceEntity and implemented it in each of the POCOs representing my lookup tables.
Using this interface, I am able to easily populate a view with a record from the lookup table. (I pass the items to the view via the following.)
System.Web.Mvc.ViewPage<MyNamespece.IReferenceEntity>
From the database to the view, every thing works perfectly.
However, when I attempt to update the model on post, I am running into some problems.
If I explicitly declare an object reference like the following, every thing works perfectly and the values of my object are updated with the values from my form. Hence, I can then update the database.
AccountStatus a = new AccountStatus();
UpdateModel(a, formCollection.ToValueProvider());
Unfortunately, hard coding the object type would completely defeat the reason for using an interface.
(A primary objective of the application is to be able to dynamically add new tables such as lookup tables without having to do anything "special". This is accomplished by reflecting on the loaded assemblies and locating any classes which implement a specific interface or base class)
My strategy is to determine the concrete type of the object at postback and then create an instance of the type through reflection. (The mechanism I use to determine type is somewhat primitive. I include it as a hidden field within the form. Better ideas are welcome.)
When I create an instance of the object using reflection through any of the following methods, none of the objects are being updated by UpdateModel.
Type t = {Magically Determined Type}
object b = Activator.CreatorInstance(t);
UpdateModel(b, formCollection.ToValueProvider());
Type t = {Magically Determined Type}
var c = Activator.CreatorInstance(t);
UpdateModel(c, formCollection.ToValueProvider());
Type t = {Magically Determined Type}
IReferenceEntity d = Activator.CreatorInstance(t);
UpdateModel(d, formCollection.ToValueProvider());
Note: I have verified that the objects which are being created through relection are all of the proper type.
Does anyone have any idea why this might be happening? I am somewhat stumped.
If I was really "hard up", I could create factory object which would many instantiate any one of these reference entity/lookup objects. However, this would break the application's ability to allow for new lookup tables to be added and discovered transparently and is just not quite as clean.
Also, I could try deriving from an actual ReferenceEntity base class as opposed to an interface, but I am doubtful whether this would make any difference. The issue appears to be with using reflection created objects in the modelbinder.
Any help is appreciated.
Anthony
Augi answered this on ASP.NET forums. It worked with only a couple of minor modifications. Thank you Augi.
The problem is that [Try]UpdateModel methods allow to specify model type using generic parameter only so they don't allow dynamic model type specification. I have created issue ticket for this.
You can see TryModelUpdate method implementation here. So it's not difficult to write own overload:
public virtual bool TryUpdateModelDynamic<TModel>(TModel model, string prefix, string[] includeProperties, string[] excludeProperties, IDictionary<string, ValueProviderResult> valueProvider) where TModel : class
{
if (model == null)
{
throw new ArgumentNullException("model");
}
if (valueProvider == null)
{
throw new ArgumentNullException("valueProvider");
}
//Predicate<string> propertyFilter = propertyName => BindAttribute.IsPropertyAllowed(propertyName, includeProperties, excludeProperties);
IModelBinder binder = Binders.GetBinder( /*typeof(TModel)*/model.GetType());
ModelBindingContext bindingContext = new ModelBindingContext()
{
Model = model,
ModelName = prefix,
ModelState = ModelState,
//ModelType = typeof(TModel), // old
ModelType = model.GetType(),
// new
//PropertyFilter = propertyFilter,
ValueProvider = valueProvider
};
binder.BindModel(ControllerContext, bindingContext);
return ModelState.IsValid;
}
Does your IReferenceEntity contain setters on the properties as well as getters? I would think that the last sample would work if the interface had property setters, though you'd have to cast it to get it to compile.
Type t = {Magically Determined Type}
IReferenceEntity d = Activator.CreatorInstance(t) as IReferenceEntity;
UpdateModel(d, formCollection.ToValueProvider());
Normally the reason that it won't set a property on a class is because it can't find a public setter method available to use via reflection.
Just a quick "another thing to try":
UpdateModel(d as IReferenceEntity, formCollection.ToValueProvider());
Not sure if that will work, and I haven't tried it myself, but it's the first thing that came to mind.
If I get a chance later I'll peek at the Default Model Binder code and see if there's anything in there that is obvious...

Does Grails have a neat way of copy domain properties from a URL query string?

I know Grails has a map based constructor for domain objects, to which you can pass the params of a URL to and it will apply the appropriate field settings to the object using introspection, like this...
myDomainInstance = new MyObject(params)
I was wondering whether there was an equivalent method of taking the params and applying them to an existing object and updating values in the same way that the map constructor must work, something like...
myDomainInstance = params
or
myDomainInstance = fromParams(params)
Am I just wishful thinking or does such a thing exist? I can code it up myself but would rather not if it exists already.
Thanks
Adapted from the grails user guide:
obj = MyObject.get(1)
obj.properties = params
Check out the documentation for 'params' under the controller section for more information.
It really depends on what you are trying to do but an equivalent approach use databinding.
def sc = new SaveCommand()
bindData(sc, params)
This give you the benefit of using custom binding. If let say your date format is not the default one you can redefine it through a bean like this:
public class CustomPropertyEditorRegistrar implements PropertyEditorRegistrar {
public void registerCustomEditors(PropertyEditorRegistry registry) {
registry.registerCustomEditor(Date.class, new CustomDateEditor(new SimpleDateFormat("dd/MM/yyyy"), true));
}
}

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