Databases
StackOverflow2013
Postsdbo
POBinding non-sequential lists with a custom model binder
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POBinding non-sequential lists with a custom model binder
    primarykey
    data
    text
    <p>I know that if I want to bind non-sequential elements to a list in MVC I can use the <code>Index</code> syntax described <a href="http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx" rel="noreferrer">here</a>.</p> <p>However, I'm unable to get remote validation to work with this (using the <a href="http://msdn.microsoft.com/en-us/library/system.web.mvc.remoteattribute%28v=vs.98%29.aspx" rel="noreferrer"><code>Remote</code></a> attribute). </p> <p>For example, if I had a model like this:</p> <pre><code>public class AddUsers { public List&lt;User&gt; Users { get; set; } public string Comment { get; set; } } public class User { [Remote("UsernameAvailable", "User")] public string Name { get; set; } } </code></pre> <p>Then suppose in my view I have the following (I'm deliberately leaving out Html helpers I'm using for clarity):</p> <pre><code>&lt;input type="hidden" name="Users.Index" value="foo" /&gt; &lt;input type="text" name="Users[foo].Name" /&gt; &lt;input type="hidden" name="Users.Index" value="bar" /&gt; &lt;input type="text" name="Users[bar].Name" /&gt; </code></pre> <p>In a form post, the <code>Index</code> field goes along for the ride, which helps the model binder bind everything nicely, like:</p> <pre><code>Comment=bla&amp;Users.Index=foo&amp;Users[foo].Name=john&amp;Users.Index=bar&amp;Users[bar].Name=bob </code></pre> <p>But when remote validation triggers, only this is sent to my action (two separate requests, one for each item being validated):</p> <pre><code>Users[foo].Name=john Users[bar].Name=bob </code></pre> <p>Without an <code>Index</code>, The model binder doesn't know what to do with this. It can neither bind to a <code>User</code>, a <code>List&lt;User&gt;</code>, nor an <code>AddUser</code>.</p> <p>Which brings me to my question.</p> <p>Would there be a way to write a custom model binder that can handle non-sequential lists without needing to use the <code>Index</code> notation? I must admit that it is difficult for me to see why the <code>Index</code> notation would be necessary (except perhaps as an optimization of some kind).</p> <p>I'm using MVC 4, and .NET 4.5.</p> <p><strong>Note:</strong> I've never messed around with custom model binders before, so I'm really just looking for some general guidance about whether it would be possible (or just a dead end), and possibly some pointers for getting started.</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USEric
    1. USEric
    plurals
    1. PL
      singulars
      1. LTLinked
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. POBinding non-sequential lists with a custom model binder
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POBinding non-sequential lists with a custom model binder
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POBinding non-sequential lists with a custom model binder
      1. This table or related slice is empty.
      1. VTUpMod
    1. COIn theory the Remote validator should work fine. Can you maybe extend your post how do you want to use the Remote validor and remote action looks like?
      singulars
      1. POBinding non-sequential lists with a custom model binder
      1. USnemesv
    2. CO@nemesv, I have updated my post. Is this enough clarification? Neither a validation action taking a `User`, a `List<User>` nor an `AddUser` will be able to bind, because the `Index` is missing.
      singulars
      1. POBinding non-sequential lists with a custom model binder
      1. USEric
    3. COI was able to solve my problem by adapting the solution from [this answer][1] [1]: http://stackoverflow.com/a/10801577/546561
      singulars
      1. POBinding non-sequential lists with a custom model binder
      1. USEric
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload