I am trying to add commandlink programatically, but I am not able to add action.
HtmlCommandLink link = new HtmlCommandLink();
link.setValue(data);
link.setActionExpression(no idea);
How do I create it?
Use ExpressionFactory#createMethodExpression().
Here's a convenience method:
private static MethodExpression createMethodExpression(String expression, Class<?> returnType) {
FacesContext context = FacesContext.getCurrentInstance();
return context.getApplication().getExpressionFactory().createMethodExpression(
context.getELContext(), expression, returnType, new Class[0]);
}
Here's how you could use it, provided that you've a public String doSomething() {} action in a managed bean identified by #{bean}:
link.setActionExpression(createMethodExpression("#{bean.doSomething}", String.class));
Related
I work with iOS throw Xamarin. I want's send byte[] from one viewModel to another using showviewmodel.
I invoke this Command:
private MvxCommand _editUser;
public System.Windows.Input.ICommand EditUser
{
get{
return new MvxCommand
(() => ShowViewModel<UserViewModel> (new {array = new byte[3]}));
}
}
and wait my byte[] as param in Init method on another viewModel(UserViewModel):
public void Init(byte[] array)
{
}
Constructor works good, but then does not reach the the Init method;
It throws an exception:
Failed to construct and initialize ViewModel for type AccountApp.Core.iOS.UserViewModel from locator MvxDefaultViewModelLocator - check MvxTrace for more information.
Any ideas?
Thanks.
Only strings, ints, doubles and bools are allowed in this constructor parameter passing at present. You would need to serialize this byte[] array to a string and then reconstruct it in the constructor of the view model you are navigating to.
I am developing a utility class, using this we need to call a managed bean method which is defined in EL Expression. Is there any examples like how to invoke a managed bean method using EL expression.
Here I don't know the type of Managed bean. but I know EL expression. So I cannot type cast to specific managed bean.
The expression is: #{phaseListenerBean.compListener}
How can my code call the compListener method on phaseListenerBean?
My Utility class. It is avaliable in a Jar file.
`public void beforePhase(PhaseEvent event) {
if(PhaseId.RENDER_RESPONSE.equals(event.getPhaseId())){
SystemListLoaderHelper.populateSelectOneValidValues();
SystemListLoaderHelper.populateSelectManyCheckboxValidValues();
FacesContext context = FacesContext.getCurrentInstance();
ExpressionFactory factory =context.getApplication().getExpressionFactory();
MethodExpression methodExpression = factory.createMethodExpression(
context.getELContext(), "#{phaseListenerBean.callModuleSpecificServiceCalls}",
Void.class.getClass(), null);
methodExpression.invoke(context.getELContext(), null);
// callModuleSpecificServiceCalls();
}
}`
You can try call the bean with the Faces context, for example if you want the bean, you can use:
FacesContext facesContext = FacesContext.getCurrentInstance();
Object o = facesContext.getApplication().evaluateExpressionGet(facesContext,
"#{phaseListenerBean}", Object.class);
And later use reflection to call the method or, You can call the method whith your expression, like this:
FacesContext fc = getContext();
ExpressionFactory factory = getExpressionFactory();
methodExpression = factory.createMethodExpression(
fc.getELContext(), "#{phaseListenerBean.compListener}",
Void.class, (Class<?>) null);
methodExpression.invoke(fc.getELContext(), null);
Please show some code for "compListener" and the utility class. Sorry for my bad english,
Cheers
I'm try to build a static property on a static class that will basically return a cookie value, to be used across my MVC site (MVC 3, if it matters). Something like this:
public static class SharedData
{
public static string SomeValue
{
get
{
if (HttpContext.Current.Request.Cookies["SomeValue"] == null)
{
CreateNewSomeValue();
}
return HttpContext.Current.Request.Cookies["SomeValue"].Value.ToString();
}
}
}
I need to access this from within controller actions, global.asax methods, and action filters. But the problem is, when action filters run, HttpContext is not available. Right now, I have to have a separate static method just to pull the cookie from the filter context that I pass in, which seems awkward.
What is the best solution for building such a static method for retrieving a cookie value like this that works from both controller actions and action filters? Or is there a better approach for doing something like this?
Thanks in advance.
The call to the static HttpContext.Current is not good design. Instead, create an extension method to access the cookie from an instance of HttpContext and HttpContextBase.
I wrote a little helper for you. You can use it to perform your functionality from within an action filter.
public static class CookieHelper
{
private const string SomeValue = "SomeValue";
public static string get_SomeValue(this HttpContextBase httpContext)
{
if(httpContext.Request.Cookies[SomeValue]==null)
{
string value = CreateNewSomeValue();
httpContext.set_SomeValue(value);
return value;
}
return httpContext.Request.Cookies[SomeValue].Value;
}
public static void set_SomeValue(this HttpContextBase httpContext, string value)
{
var someValueCookie = new HttpCookie(SomeValue, value);
if (httpContext.Request.Cookies.AllKeys.Contains(SR.session))
{
httpContext.Response.Cookies.Set(someValueCookie);
}
else
{
httpContext.Response.Cookies.Add(someValueCookie);
}
}
}
Note: You could easily make these methods work on HttpContext instead just by replacing the HttpContextBase parameter with HttpContext.
As JohnnyO pointed out above, I had access to HttpContext from within my action filter all along. At least, in the particular action filter method where this was needed. There may have been some other filter/method that did not have access at one point, but for now, this is working as I need it to.
hi i defined one class to create cookie by received parameter's from user. when i want to add cookie to context i receive an exception.
My Class
public static class ManageCookies
{
public static void Create(string name, string value)
{
HttpCookie cookie = new HttpCookie(name);
cookie.Value = value;
cookie.Expires = DateTime.Now.AddYears(1);
HttpContext.Current.Response.Cookies.Add(cookie);
}
}
Occured Exception: Response is not available in this context.
i know it is connected with the context within the current sub is executing.
i whould suggest my function to pass the current HttpResponse as a parametter to that!
public static class ManageCookies
{
public static void Create(string name, string value, HttpResponse response)
{
HttpCookie cookie = new HttpCookie(name);
cookie.Value = value;
cookie.Expires = DateTime.Now.AddYears(1);
response.Cookies.Add(cookie);
}
public static void PrePareForApplicationStart()
{
Create("somecookie", "somevalue", _context);
}
}
this is correct way? why? and are you have another way?
UPDATE: Oppps! using this way still have First Exception! :(( Help Help
ManageCookies manager = new ManageCookies(this.Context);
manager.PrePareForApplicationStart();
i use above code to send HTTPContext object to defined class. it called from Application_Start event.
and ManageCookies class updated as below:
public class ManageCookies
{
private HttpContext _context;
public ManageCookies(HttpContext context)
{
this._context = context;
}
}
i use this variable (_context) to adding cookies!
The code you provided is not a problem the problem is where you call it from. If you call it after the response is flushed or from a thread other than the one assigned to process your request - you can get all sorts of problems
In response to Sadegh clarification:
This is exactly the point. Application Start happens only once during application lifetime. And I guess you want this cookie to be delivered as a part of every response. In other words on ApplicationStart is not the right place to do it. You can do it at any moment during page lifecycle BEFORE the end of the PreRender
I'm building small web shop with asp.net mvc and Structuremap ioc/di. My Basket class uses session object for persistence, and I want use SM to create my basket object through IBasket interface. My basket implementation need HttpSessionStateBase (session state wrapper from mvc) in constructor, which is available inside Controller/Action. How do I register my IBasket implementation for SM?
This is my basket interface:
public interface IBasketService {
BasketContent GetBasket();
void AddItem(Product productItem);
void RemoveItem(Guid guid);
}
And SM registration:
ForRequestedType(typeof (IBasketService)).TheDefaultIsConcreteType(typeof (StoreBasketService));
But my StoreBasketService implementation has constructor:
public StoreBasketService(HttpSessionStateBase sessionState)
How do I provide HttpSessionStateBase object to SM, which is available only in controller?
This is my first use of SM IOC/DI, and cann't find solution/example in official documentation and web site ;)
If you absolutely have to have your StoreBasketService use the session, I'd be tempted to define an interface and wrapper around HttpSessionState instead of using HttpSessionStateBase so that you can register it with StructureMap as well.The wrapper would get the session state from the current context. Register the wrapper with StructureMap and then have your StoreBasketService take the interface as the argument to the constructor. Structure map should then know how to create an instance of the interface wrapper and inject it into your StoreBasketService class.
Using an interface and wrapper will allow you to mock the wrapper in your unit tests, muc in the same way HttpSessionStateBase allows mocking the actual session.
public interface IHttpSessionStateWrapper
{
HttpSessionState GetSessionState();
}
public class HttpSessionStateWrapper : IHttpSessionStateWrapper
{
public virtual HttpSessionState GetSessionState()
{
return HttpContext.Current.Session;
}
}
ForRquestedType(typeof(IHttpSessionStateWrapper))
.TheDefaultIsConcreteType(typeof(IHttpSessionStateWrapper));
public class StoreBasketService
{
HttpSessionState session;
public StoreBasketService( IHttpSessionstateWrapper wrapper )
{
session = wrapper.GetSessionState();
}
// basket implementation ...
}
However, you can have StructureMap actually store your basket in the session using .CacheBy(InstanceScope.HttpContext) when registering it. It may actually be better to have your StoreBasketService implement internal storage instead of storing things in the session -- then you lose the dependency on the session state entirely (from the perspective of your class) and your solution could be simpler. Your internal storage could be a Dictionary<Guid,Product> since this is how you access them via your interface.
See also:
http://www.lostechies.com/blogs/chad_myers/archive/2008/07/15/structuremap-basic-scenario-usage.aspx
http://www.lostechies.com/blogs/chad_myers/archive/2008/07/17/structuremap-medium-level-usage-scenarios.aspx
ForRequestedType<IBasketService>()
.TheDefault.Is.OfConcreteType<StoreBasketService>()
.WithCtorArg("sessionState").EqualTo(HttpContext.Current.Session);
?? does that work?
I just started with StructureMap, and I do not get the results you are describing.
I performed a simple test using a simple class, configuring Structuremap to cacheby HttpContext, and from what I can see, CacheBy.HttpContext means within the same request you will get the same instance... not within the same Session
The constructor of my class, sets the date/time in a private field
I have a button which gets 2 instances of MyClass with one second interval...
It then display the time of both instances in a label.
Pressing the first time this button, object A and B are same instance, as their creation time is exactly the same, as expected.
Clicking the button a second time, you would expect the creation time to not have changed if instances would be cached in session... however, in my test I get a new creation time ...
Structuremap configuration:
ObjectFactory.Initialize(x=>x.ForRequestedType<MyClass>(). CacheBy(InstanceScope.HttpContext));
Button clicked event of test page
protected void btnTest_Click(object sender, EventArgs e)
{
MyClass c = ObjectFactory.GetInstance<MyClass>();
System.Threading.Thread.Sleep(1000);
MyClass b = ObjectFactory.GetInstance<MyClass>();
lblResult.Text = String.Format("cache by httpcontext First:{0} Second:{1} session id {2} ", c.GetTimeCreated(), b.GetTimeCreated(),Session.SessionID);
}
MyClass
public class MyClass
{
private DateTime _timeCreated;
public MyClass()
{
_timeCreated = DateTime.Now;
}
public string GetTimeCreated()
{
return _timeCreated.ToString("dd/MM/yyyy hh:mm:ss");
}
}
You could also use one of the ObjectFactory.Inject methods to inject the HttpSessionStateBase into StructureMap. It would then invoke the constructor with the injected HttpSessionStateBase.
I just made my first attempt at creating an custom scope... build a small web application with it, and as far as I can see, it seems to work. This will cache the object inside the current user session and will return the same object as long as you remain inside the same session:
public class HttpSessionBuilder : CacheInterceptor
{
private readonly string _prefix = Guid.NewGuid().ToString();
protected override CacheInterceptor clone()
{
return this;
}
private string getKey(string instanceKey, Type pluginType)
{
return string.Format("{0}:{1}:{2}", pluginType.AssemblyQualifiedName, instanceKey, this._prefix);
}
public static bool HasContext()
{
return (HttpContext.Current.Session != null);
}
protected override bool isCached(string instanceKey, Type pluginType)
{
return HttpContext.Current.Session[this.getKey(instanceKey, pluginType)] != null;
}
protected override object retrieveFromCache(string instanceKey, Type pluginType)
{
return HttpContext.Current.Session[this.getKey(instanceKey, pluginType)];
}
protected override void storeInCache(string instanceKey, Type pluginType, object instance)
{
HttpContext.Current.Session.Add(this.getKey(instanceKey, pluginType), instance);
}
}
You have to configure the ObjectFactory as follows in the global.asax Application_start
ObjectFactory.Initialize(x=>
x.ForRequestedType<MyClass>().InterceptConstructionWith(new HttpSessionBuilder()));