ADO.NET :: Write Custom Functionality To Access The Model (POCO) Metadata
Dec 7, 2010
I was wondering if anyone can point me in the right direction? I have a POCO model and I am using Code First CTP. In my application, I set the database to be recreated whenever the model changes.
I would like to write custom functionality to access the model (POCO) metadata same way as EF sees it and use that to generate some source files (using T4). I would like to access the processed model not having to worry about finding properties that hold primary keys or any other conventions (implicit or not). What is the way to go about it?
I'm working on an ASP.NET MVC 2 project with some business entities that have metadata dataannotations attributes applied to them (Validation attributes, Display attributes, etc.).
Something like:
[Code]....
Using the metadata from different views is no problem, as long as I am using my business entities as viewmodels or as part of a viewmodel like this:
[Code]....
However, sometimes I need to code a view for editing some, but not all fields of an entity. For those fields I want to reuse the metadata already specified in my user entity. The other fields should be ignored. I'm talking about custom view models like this:
[Code]....
That's where I am running into problems. The custom view model above leads to an exception when the view is generated, because it has no password property.
The associated metadata type for type 'Zeiterfassung.Models.ViewModels.Users.UserNameViewModel+UserModel' contains the following unknown properties or fields: Password. make sure that the names of these members match the names of the properties on the main type.
Also, even if this exception did not occur, I expect to get into even more trouble with model validation on form submit because Password is marked as required in my business entity.
I can think of several workarounds, but none seem really ideal. In any case I can't change the database layout so that the password field would be in a separate entity in my example above.
I would like to extend the HtmlHelper by using metadata (similar to DataAnnotaions metadata). Specifically I want to be able to add a 'Title' attribute to html controls that will then appear as a tooltip on the control. I would like to keep the tooltip text with my model, for example by adding 'Tiltle' metadata to the model as follows:
[DisplayName("User Id")] [Title("Enter your 10 digit user id")] property UserId { get; set; }
So the questions are:
1. How do I add metadata (such as 'Title') to my model?
2. How do I access this metadata in my HtmlHelper extension method?
My case:I am developing an application that will run for multiple clients, each client has the ability to customize field displays and error messages.My issue:I created some custom attributes which inherit from DisplayNameAttribute, RequiredAttribute etc... and in them I am pulling out the resource needed.However it is only executed the once, so if my context changes it will be pulling the incorrectly cached value instead of pulling the new value need.Has anybody attempted to try something like this with the data annotations? Or any advice such as just don't use them for this scenario?
In my project I use Strong Types Views. Because I find it nice structured.
public abstract class AbstractViewData: View Page ( ICollection Foo; ) public class HTML Component View Data: AbstractViewData ( string Foo2; )
I have the same structure in my code, as in the corresponding pages.And here starts the problems. I would like to use HTML.Display (o => o.Foo) could be a customer for that matter.But my Strong Types Views have not posted Metadata Model into my classes.Like: Return View ( "FooView", customer); would.Is there a way to write some code that can solve this problem for me?
i am working an asp.net mvc 2 web app using model metadata and some of the model metadata don't seem to work when using the default Html.EditorForModel().For example, when applying the DefaultValue(1) and the ReadOnly(true) attributes on a model field, the field displayed on edit view has zero for its default value and it is not read only.
I would like to separate my attribute decoration(3-4 per field) by having them someplace else so that my code looks readable.Also the arguments passed to some attributes should come from a resource file.EG:[Required("Cannot proceed without entering *field_Name*")]
I need just [Required] Possible duplicate of this question(on which i couldn't resist offering a bounty) : Default resource for data annotations.
I have a view that is strongly typed and its model is of type LogOnModel. That LogOnModel has anotated properties like this one:
[Required(ErrorMessage = "Please enter your password")] [DataType(DataType.Password)] [Display(Name = "Password", Description = "Your secreet password")] public string Password { get; set; }
All of them has Display anotation with Display.Descripion property set. I want to create HtmlHelper extension method that will output <span> containg the value of Display.Description property. So for example if I called my extension method DescriptionFor than this code:
<%: Html.DescriptionFor(m => m.Password) %>
should produce following html: <span>Your secreet password</span>
Is there anything missing in IIS 6.0 that prevents me from (Insert into table) using MS-Access?
Explain: The application works fine under Visual Studio 2008 IDE the insert into table works fine with no error, Also I tested with hosting provider and works fine with no problem. but now I have published the same exact app in a dedicated server windows 2003 with IIS 6.0 .NET framework 2.0 with latest service pack I gave IIS_WPG write/modify access to the folder where MS-Access database is located and database but at the time of insert an error pop-up. I need to install in the Server or settings in the IIS to recognize my MS-Access db is it some office runtime that I am missing. (BTW I am using OLEDB connection string in my C# )
Using System.Data.OleDb;
I can retrieve data off of it with no problem but when I try to insert is when it fails I thought the problem was Access Rights but I do not think is the case.
I am very new to Web development, and have been writing some javascript that makes use of WScript.Shell via ActiveX. I am aware that browsers other than IE don't support ActiveX though.
After doing some digging through Google, I have discovered that I may be able to do something similar on all web kit based browsers via NPAPI. I have no idea where to even begin when it comes to this though. Is it possible to do what I am after via NPAPI? If so, where would I begin?
What I'm trying to do is rather basic, but I might have my facts mixed up. I have a details page that has a custom class as it's Model. The custom class uses 2 custom objects with yet another custom object a property of one of the 2. The details page outputs a fair amount of information, but allows the user to post a comment. When the user clicks the post button, the page gets posted to a Details action that looks something like this:
[AcceptVerbs(HttpVerbs.Post)] public ActionResult Details(VideoDetailModel vidAndComment) { ....} [Code]....
The only fields on the form that is posted are CommentText and VideoId. Here is what the VideoDetailModel looks like.
public class VideoDetailModel { public VideoDetailModel() { [Code].... I suppose if I added more form fields for the properties I need, they would get posted, but I only need 1 form entry field for the CommentText. If I could get the same Model objects value that were sent to the page to post with the page, it looks like the solution is rather simple. I think using the RenderPartial in the middle of a form is problematic somehow to how the form gets written in html. I can't really put my finger on why things went bonkers, but if I do my RenderPartials before my form and then begin my form with the text entry field and the hidden VideoId, the default ModelBinder works just fine. I was beginning the form, writing the hidden VideoId, rendering several partial views, create my CommentText field, and then closed the form out. The CommentText field would get bound just fine. The hidden VideoId would not. Maybe I missed a rule somewhere about using RenderPartial.
For completeness, the partial view I was rendering took a Comment object and just wrote out it's CommentText data. Several of these objects would exist for a single Video object. All of this data was in a custom type and passed into the View (the main view) as it's Model. This partial view did not have a form and did not have any data entry fields.
is it posible to add client side functionality to a custom server control in vb.net?i am looking at msdn library and there is no code for vb :/ http://msdn.microsoft.com/en-us/library/aa719700%28v=VS.71%29.aspxI fount this on MSDN Library Adding Client Capabilities to a Web Server ControlWhat i'm trying to do is to add some client functionality to my control, so that you can get or set some properties/values on client side. From the above link i see that this is doable with Ajax Server Control, but i don't have it, i have Custom Server Control. Can i do this with Custom Server Control and how?
i am just having a play with HtmlHelpers in MVC, very useful stuff and now i am trying to create one for dropdowns based on passing in a model ( any ) what the property is for the value and same for text.
I have used standard asp.net roles and membership provider in my asp.net mvc project. The resources like creating an employee and setting its role can only be done by administrator. Now at first delivery of software to client, there will be no user, i want to implement a functionality where if there are no users in the system user can directly create new employee and assign roles without logging in. Once the roles are assigned user will have to log in to access authorized resources. Can i implement custom action filters that will assist me in implementing this functionality? How can i impelment this functionality?
Here's the Design View: I'd like to add code in the code behind to perform additional edits. I added the "ErrorMessage" LiteralControl. How do I access it from the code behind or is there a preffered way to display a custom message using the control's functionality?
Normally I work in ASP Classic, and am still a bit green on ASP.Net MVC.
I have my model with its fields or entities (might not be the right word hence why not able to find if previously answered, forgive me), and some of these will have null values such as hyperlinks, email address, specific types of phone numbers, etc.
What I want to do is not write certain blocks of HTML within the foreach loop if a field is empty.
In ASP Classic, I would have written an If statement along the lines of:
<% If RS.field <> NULL then %>HTML with <%=RS.field %><% End If %> <% If RS.field2 <> NULL then %>HTML with <%=RS.field2 %><% End If %> ...
However, I don't know how to achieve the same result in ASP.Net MVC.In one of my current usages, a list of sellers returned for a specific set of search results, it runs through a foreach loop and returns the current HTML (in part):
Website: <a class="url" href="<%= seller.ContactWebsite %>" target="_blank" title="Visit the website for <%= seller.Name %>"><%= seller.ContactWebsite %></a><br />
So, if for example I have a field from the model, say seller.ContactWebsite, and this field was NULL, I would not want it to write this as part of the foreach loop.
I am trying to understand a little more about implementing a custom model validator. I have implemented a custom model validator (derived from DataAnnotationsModelValidator<T>) for my custom validation attribute in order to do validation on the client side as well. There is not much documented about DataAnnotationsModelValidator. Besides, implementing client-side validation when is it a good idea or needed to implement a custom model validator for a custom attribute?
A separate question - in trying to understand how and when a custom model validator is used by the framework I noticed that my custom validator is always created with the context (2nd parameter in DataAnnotationsModelValidator<T>'s constructor) being a ViewContext, although it is declared as ControllerContext. Will a validator ever be created with something else than a ViewContext, and if so, when?
'm building a custom MetadataProvider and I'd like to access the actuall model value in the CreateMetadata method.
[Code]....
When the current model value is of type string, the model value can be found in metadata.Model. But when the model is of reference type the value is null.
So I have one custom model binder that inherits from DefaultModelBinder, where I am overriding the BindProperty() method to handle a type of field we've created. I also have one controller that we'd like to override BindModel() on, since we're handling an object in session for multiple views with that controller.
So I have CustomModelBinder : DefaultModelBinder, and then in the class where we override BindModel() i have that inheriting from CustomModelBinder. SpecialModelBinder: CustomModelBinder
But I have set a breakpoint in our override of BindProperty() in CustomModelBinder, and this never gets hit when using the controller that is also overriding BindModel(). Can I not inherit like this? What's happening here?
edit: in global.asax: ModelBinders.Binders.Add(typeof(ClassA), new SpecialModelBinder()); ModelBinders.Binders.Add(typeof(ClassB), new CustomModelBinder()); ModelBinders.Binders.Add(typeof(ClassC), new CustomModelBinder()); ModelBinders.Binders.Add(typeof(ClassD), new CustomModelBinder()); public class CustomModelBinder : DefaultModelBinder { // this will be hit in controllers that handle classes B, C, and D, but will not be hit in controller that handles ClassA protected override void BindProperty(...){} } public class SpecialModelBinder : CustomModelBinder { // this will be hit when working in controller that handles ClassA only public override object BindModel(...){} }
I am working on the example from Steven Sanderson's book 'Pro ASP.NET MVC Framework'. The cart class is coming up as empty in my Index action method of CartController class.
