A minor question that I hope admits of a simple answer that I'll kick myself for not noticing.
So, when we have the following overload of RegisterStartupScript
public static void RegisterStartupScript(
Control control,
Type type,
string key,
string script,
bool addScriptTags
)
we have to provide a type as well as a control. Now, I can see what the point of specifying the control - the script gets pushed out just in case the control is part of the partial page render. But what is the point of the Type parameter? Usually one just sets it to the type of the control. And this is in fact the suggestion made by MSDN:
control
Type: System.Web.UI..::.Control
The control that is registering the client script block.
type
Type: System..::.Type
The type of the client script block. This parameter is usually specified by using the typeof operator (C#) or the GetType operator (Visual Basic) to retrieve the type of the control that is registering the script.
So why do we have to specify it? Presumably not just to spare the .Net Framework the bother of retrieving the runtime type itself.
Usually type is the type of the page or control that registers a script. This is just a way to prevent that two different controls register different scripts using the same key.
Excerpt from MSDN:
A client script is uniquely identified
by its key and its type. Scripts with
the same key and type are considered
duplicates. Only one script with a
given type and key pair can be
registered with the page. Attempting
to register a script that is already
registered does not create a duplicate
of the script.
Related
I'm working in an ASP.NET (VB) Web Application with Windows/Active Directory Authentication
I am using a module so that I can call public subroutines and functions, and reference variables, without having to instantiate a new object to access them on each page.
Within that module, I have some Public variables that I am using in multiple pages throughout the web application. I've recently realized that the values for these public variables in the module get shared between all users.
THE GOAL:
I want the value for these global variables to be specific to a single user and not shared between all sessions, and I do not want to have to instantiate a new object/class on every page that uses the variable.
THE CATCH:
I don't want to store the value in a client-side variable such as a cookie or session. I want the value to be stored on the SERVER but specific to each client/user.
The only thing I can think to do is setup a global collection/dictionary and store the variables with the authenticated user names, but then I need to have specific functions to get and set the values. While this will work, it requires all the references to these variables on all pages in the application to be updated.
EXAMPLE OF THE PROBLEM:
The below code shows how I am creating the public variable within the module and how the value is being set from one page and used on another. I'd like to continue to use this variable in the same way and share it's value between pages, but the value of the variable needs to NOT be shared between users.
-- MODULE.VB --
Public Module MyMod
Public myVariable as String = ""
End Module
-- MAINPAGE.VB --
Partial Class _Default
Sub Page_Load() Handles MyBase.Load()
myVariable = "HELLO WORLD"
End Sub
End Class
-- NEXTPAGE.VB --
Partial Class _Default
Sub Page_Load() Handles MyBase.Load()
Response.Write(myVariable)
End Sub
End Class
There are a LOT of pages in this application that will need to be manually updated if I have to use my userID-indexed collection solution, so I'm hoping there is a way to simply scope these variables differently or a way to disable the sharing between sessions.
Thanks in advance!
You didn't indicate whether or not the variables need to be persisted across page round trips or whether they are just used within each page's lifecycle.
If they are not persisted across pages, then perhaps the easiest solution is to have all of your pages inherit from a based page class and then move the values from the module into the base page. This way you won't have to change any variable references, only page inheritance.
If you do want to persist the values, completing the above changes makes it much easier to implement. You can then turn the member variables on the base page into properties and embed your user specific caching and fetching in the getter and setter.
For example, instead of:
Public MyVariable As String = ""
You would have something like:
Public Property MyVariable As String
Get
Return GlobalMyVariableCache(UserNameKey)
End Get
Set (Value As String)
GlobalMyVariableCache(UserNameKey) = Value
End Set
End Property
The problem you are coming across is a very common one in web programming. A Module's members are static - meaning there is one instance of them across the entire AppDomain of your application. Every user that accesses these will get the same object - you have already learned this.
Your options are exactly what you described. You could possibly replace the public variable in your module with a property whose getter you write to access a user-specific field in a dictionary (please remember thread safety when writing this getter code).
The much easier solution would be to use the Session. Session values are stored server-side and are user specific. The only thing that get's sent client side is the session key, and if you are using .Net authentication, this is likely already getting sent.
Good luck,
There's a lot of question (and answer) here on stackoverflow and other site about translating the default error messages provided by the DefaultModelBinder, such as this one or this one.
All answers to these questions basically proprose to create a ressource (resx) file under App_GlobalResources and put a message for "PropertyValueInvalid".
That's fine, it does works, but there is other message also (ex. "The value xxx must be a number") and the big question is : where in hell can I have a list of the messages key used for model binding validation, with a description of the context they are used for so I can translate each of them ?
When DefaultModelBinder.ResourceClassKey = "ResourceFileName"; is set in Application_Start method the DefaultModelBinder class uses other resource keys than defined in the resource file used by Asp.Net MVC.
While disassembling DefaultModelBinder there is a method GetUserResourceString that reads from the custom resource file. This functions is only called twice with these messages keys:
PropertyValueRequired (A value is required.)
PropertyValueInvalid (The value '{0}' is not valid for {1}.)
These are the only messages that could be set for DefaultModelBinder in MVC3.
Another simple questions.
I have website with different languages. If I want to access a string from the resource file I would use it like this
Resources.MyResourceFile.MyStringIdentifier
Very easy. That way I know during compile time, that the resource string exists.
Now, this works only if I want to use the current Culture. Sometimes I need to specify a specific culture (let's say that the current user uses German as a language, but his action triggers messages to be sent to other users which will be in the recipient's language). Now, I see two options:
Resources.MyResourceFile.ResourceManager.GetString("MyStringIdentifier", neededCulturInfo)
The other would be to change the current thread's culture info which I would need to do several times.
Is there a third way? Something which tells me at compile time that the resources exist but without the need to change the thread's culture all the time?
(For your scenario) the idea of the ResourceManager is to provide culture specific informations at runtime not at compile time (aka side-by-side with fallback).
So the answer is "NO", there isn't a buildin way to determinate the existance of those resource files at compile time - to do so you would require a kind of "hard coding" for all strings in every single langauge and also code to access to those. The side by side idea is exactly the opposite of hardcoding ;)
What you could do, is writng a unit test for the resources, that itterates your langauges and checks if the default or a localized value was used. Further if you are using a source control system that provides check-in policies (e.g. TFS) you could this unit test as part of the check-in policy.
Have you tryied :
public static Object GetLocalResourceObject (
string virtualPath,
string resourceKey,
CultureInfo culture)
Try this link Click here
You can also try:
public static Object GetGlobalResourceObject (
string classKey,
string resourceKey,
CultureInfo culture)
Try this link Click here
ResourceSet has a method
public virtual IDictionaryEnumerator GetEnumerator()
that gives access to key-value pairs of the resource file.
E.g. (assuming we deal only with strings - N.B. the key-value pairs are of type object):
while (set.MoveNext())
{
string key = (string)set.Key;
// string value = (string)set.Value;
string value = ResourceManager.GetString(key, neededCulturInfo);
}
This is not what you should do, because things become complicated - just to point it out.
You could create different resource files for different cultures and use a switch code block in a method that has a CultureInfo as parameter.
You construct a class that looks inside the resource or use the Enumerator solution,look for the value and if it does not exist, make it use the value in the default language.
But in compile time, it cannot be verified.
The easiest option is a try-catch and return the value in the general language in the catch.
Nevertheless, if we are using resources, all the keys must always be present in all the related files, even if you copy them with the general language values.
My solution is what it should be, all the resources should be consistent, if not we are using this great tool badly.
The generated Resources.MyResourceFile class has a static Culture property, which you can set to neededCultureInfo to override the current thread's CurrentUICulture.
1) At the start maybe could be useful to store the UICulture into a session, in order to change it when you want, at the begin you can change it from there.
2) You can override the UICulture in preRender and set it from there and than storing it into session.
You can store it in a cookie as well but is not the best solution for it.
You can use WorkItems to send the messages asynchronously. Since you're now running on a different Thread, you should be able to modify the CurrentUICulture as needed.
P.S.: this is a good example why static dependencies are bad and everything should be interfaces & instances.
Enterprise Library Validation Application Block (VAB) integrates with ASP.NET and also with WCF.
Is there a way to integrate ValidationResults created in WCF with ASP.NET?
e.g. an ASP.NET web page invokes a WCF service. The WCF service validates the data using VAB and returns validation information via a FaultContract. The ASP.NET page can take the results and display some error messages. However, a common approach is to indicate which fields have errors (e.g. inline message or asterisk). It seems that most of these approaches will involve being able to correlate the validation result with a control or with a validator.
I don't think there is an out of the box solution but was also curious if anyone had done this and what their approach was.
Since there is no out of the box solution and there aren't any answers posted, I will share what I implemented. I'm not in love with the approach but it is working for me.
Overview
The basic approach is for the ASP.NET page to populate a mapping between properties on the DataContract objects to the ClientId of the control that is being validated. When a validation error occurs the ClientId is returned back from the service to the asp.net page as part of a FaultContract. Then the details from the FaultException are extracted; the ASP.NET page retrieves the ClientId of the control that caused the error and appropriate action can be taken (e.g. change control look and feel or set the text on a validator).
Details
All of the DataContract objects inherit from a base class that exposes a Dictionary. This dictionary is used to map object properties to ASP.NET controls. In the Dictionary, the key is the property name on the DataContract object and the value is the ClientId of the control. Before invoking a service, the client must attach the Dictionary to the DataContract object.
When a ValidationResult is created by Enterprise Library it contains a property called Target which is the object that was validated. ValidationResult also contains a property called key which is the name of the property from the target object that was validated. The ValidationResult key is also a key into the Dictionary that was set in the ASP.NET page before calling the service.
With the ValidationResult key, the ASP.NET supplied information (ClientId) can be extracted from the ValidationResult Target. The information is then added as the Tag of the ValidationResult. Unfortunately, Tag is a readonly property so it has to be set by creating a new ValidationResult and passing the tag to the constructor.
The collection of ValidationResults is then transformed to a pre-existing CustomValidationResults collection (which looks just like ValidationResult) that we needed to use. The CustomValidationResults are then added to a custom ValidationFault and a FaultException is thrown.
The ValidationFaults are then extracted from the FaultException in the ASP.NET page. The ValidationFault contains the ClientId of the control which is associated with the error so the page can choose to display the Messages as it sees fit.
I am using methods with the Attribute [WebMethod] in my aspx pages. I don't use any asp.net ajax but jQuery to call these methods and return objects in JSON. This all works fine.
Next I added an authorization check inside the webMethod, if the current user doesn't have access to the feature I need to let the calling JavaScript know.
So I am throwing an AccessViolationException exception which can then be parsed by the OnError callback function in JavaScript. This works too but the exception includes the full StackTrace and I don't want to make this available to the calling client.
What other ways I could use to return an "Access Denied" to the client when the WebMethod returns a business object?
I'm using ASP.Net 3.5SP1 and jQuery 1.32
You can also add a:
customErrors mode="On"/
in your web.config, this will cut away the stack trace and leave you only the exception message
Why propagate errors through the wire? why not use an error response ?
Just wrap your object in a response object wich can contain an error code for status and an error message to present to users.
As suggested by NunFur I changed my approach and rather than throwing an error, I return a 'richer' object.
There are at least two options, the first one would be to encapsulate my business object into a response object with some status properties. I tried this but it makes the JSON more complicated.
So rather than adding a new object I added two properties to my business object, something like ServiceStatus and ServiceMessage. By default these are 200 and '', but can be set by the WebMethod code if anything goes wrong (no access, proper error). In this case they business object will be 'empty' (no data). The JavaScript code then first checks for the ServiceStatus and reacts appropriately.
I add the two fields to all my objects that are returned by WebMethods, even a simple string. They have to implement an Interface with those two properties.
Now I have complete control over that goes over the wire in case something unexpected is happening.
Thanks for the input
I save exceptions for when things go really wrong. (e.g. can't connect to the database)
Either return nothing (null/nill/whatever), or return a false bool value.
Sorry that I don't have a better answer than that...I'll have to keep looking myself.
You could look at SoapException: http://msdn.microsoft.com/en-us/library/system.web.services.protocols.soapexception(VS.71).aspx
I'm just not sure, if it will work when it is called from JavaScript. Espeially if it's called with a get-request.
BTW AccessViolationException is to my best knowlegde ment to be thrown when the application is accessing memory it has no access to.
/Asger