I have an insurance entry form that has contact information for two people. I have created a Razor partial view for the contact entry and put it in the form twice. The 'master' view model (VmApplicationForm) contains two instances of a subsidiary view model (VmPolicyHolder) corresponding to the two contacts as well as some properties common to both contacts. I am calling #Html.RenderPartial("_CreateOrEdit", Model.contactInfo1) and #Html.RenderPartial("_CreateOrEdit", Model.contactInfo2) in the page. With this arrangement (no surprises) the rendered code has duplicate IDs for the form input elements.
Is there any way of getting RenderPartial to prefix the IDs and Name attributes? I couldn't see this in the documentation, but perhaps I've missed something.
Sorry, I don't have time yet to give you the example code, but i'll give you the idea. You should first create EditorTemplate for that probably called ContactInfo class. And then, in the base class(Holding that two contacts) edit view, you should write
#Html.EditorFor(model => model.contactInfo1)
#Html.EditorFor(model => model.contactInfo2)
This way, it will render that EditorTemplate and generate correct ids and names to inputs within it.
What you are doing is trying to post a collection of items in a form- this can indeed be done in MVC (as well as in any web page/application that uses a FORM tag), however it requires some special handling to avoid id collisions and to correctly format the post data. Steve Sanderson has a great post on how to accomplish this:
http://blog.stevensanderson.com/2010/01/28/editing-a-variable-length-list-aspnet-mvc-2-style/
Essentially its a wrapper to append unique guids to element ids (in your case for each contactInfo), and create the proper array format in the tags. eg <input name="ContactInfo[f2cc4d6b-fc32-45e9-9d3d-fce54c3fede3].FirstName">
if your model is something like ContactInfo, you will end up posting like
[HttpPost]
public ActionResult Index(IEnumerable<ContactInfo> contacts)
{
// To do: do whatever you want with the data
}
Related
first question on stack so please be gentle ;). I have a long MVC form that requires the user to be able to click an 'Add Person' button , which would then create a copy of an 'Add Person' partial view , which is then filled in with the Person details. On form submit, the controller would then need to contain the details of each new added person stored as a Person object in the Person[] array I have in my View Model. so for example:
User clicks 'Add Person' button 3 times
3x ' Add Person' partial views are displayed on screen, one after the other
User fills in the 3 listed forms
User submits form
Model submitted to controller contains an array of 3 Person objects, populated with the values the user has entered.
I've got the EditorFor working when displaying a list of template forms for an already populated Array of Person objects, but not sure how I would go about actually inserting a new 'Person' into the model via mouse click. Each new person will need to be given an ID of Guid type.
Sorry if my question is vague.I'm trying not to be. I cant provide sample code for my exact solution as this is for a government project but can whip up an similar example if required. Thank you for your time
This should give you a general idea of how to do it
var partialView = '#Html.Raw(#Html.Partial("Person", new ViewModel()).ToString().Replace("\r\n", String.Empty).Replace("\n", String.Empty).Replace("\r", String.Empty))';
partialView = partialView.replace('id="1"', 'id=ListName_{0}'.format(newId));
$("#persons").append(partialView);
Firstly I create a variable containing the partial view as a string, next we need to change the ids and the rest of the properties so they follow the convention used for lists when data binding in MVC.
It follows the following convention
<input type="text" name="stocks[0].Key" value="MSFT" />
<input type="text" name="stocks[1].Key" value="AAPL" />
See the following for a description
http://www.hanselman.com/blog/ASPNETWireFormatForModelBindingToArraysListsCollectionsDictionaries.aspx
Once all ids are correctly created you can post the form as per usual.
You're not going to be able to add a person to the view model from client side code. The view model doesn't exist client side, only server side.
My suggestion is to make sure the partial views are all in the form being submitted and have an array of Person objects as a parameter in the controller action you're posting to. You'll need to make sure you use the correct convention for each name on each input field of each partial view.
So for example the partial view each input field would need to be named like this Person[index].Field. Where index is an integer and Field is the appropriate property from the Person model that this particular input tag represents.
I have a FormViewModel that handles different fields. Many of them have not to be presented to the user (such as modified_date, current_user_id) so I am using hidden fields to respect the FormViewModel structure. When submitted they are passed to the controller's action and correctly saved to the DB but I'm asking: is it the best way to do in ASPNET MVC? I would have preferred to define them in FormViewModel and using only the fields to be modified instead of showing also the non-modifiable as hidden fields.
Is there a better way to do it?
If these fields are not being touched by the user than I would do this;
Create a FormViewModel with only the fields that are relevant. Also the primary key.
The primary key still needs to be on the page me thinks.
Then in the controller you accept the FormViewModel as the argument, you then load the actual model and update, validate fields as required and save the model.
The above is simplistic and you'll have more layers but you should get the idea
I think you can do a few things to make your life a little easier:
Let the URL (and the routing mechanism) give you the id (the primary key of whatever you are trying to edit)
You can have a URL like '/Student/Edit/1' Routing will ensure that your Action method gets the id value directly.
Have 2 action methods to handle your request. One decorated with [HttpGet] to render the initial form to the user (where you just retrieve your object from the repository and pass it on to your View) and a [HttpPost] one to actually handle the post back from the user.
The second method could look something like:
[HttpPost]
[ActionName("Edit")]
public ActionResult EditPost(int id) {
...your code here...
}
Retrieve the actual record from the repository/store based on the id passed in.
Use the UpdateModel function to apply the changes to the database record and pass on the record back to your repository layer to store it back in the database.
However, in a real world application, you will probably want separation of concerns and decoupling between your repository and your view layer (ASP.NET MVC.)
If they are part of the model, the method you are using is perfectly fine. You even have a helper method in HtmlHelper.HiddenFor to output the hidden field for you. However, if the values are something like modified date or current user, you'd might be better suited passing those along from your controller to a DTO for your data layer. I'm making some assumptions about what you're doing for data access, though.
The risk with storing data which shouldn't be modified in hidden fields is that it can be modified using a browsers built in/extension developer tools. Upon post these changes will be saved to your database (if that's how you're handling the action).
To protect hidden fields you can use the MVC Security Extensions project https://mvcsecurity.codeplex.com.
Say the field you want to protect is Id...
On you controller post method add:
[ValidateAntiModelInjection("Id")]
Within your view add:
#Html.AntiModelInjectionFor(m => m.Id)
#Html.HiddenFor(m => m.Id)
On post your Id field will be validated.
Create a FormViewModel with only the fields that are relevant. Also the primary key.
The primary key still needs to be on the page me thinks.
Then in the controller you accept the FormViewModel as the argument, you then load the actual model and update, validate fields as required and save the model.
The above is simplistic and you'll have more layers but you should get the idea
I am still trying to figure out how to create reusable partial views in MVC
Lets say I would like to create a partial view to display a form for submitting an address.
Then in my ViewModel I have two addresses (Home address & Work Address)
So I would think that in my view I call HTML.Partial for each one like this
#Html.Partial("Address", Model.HomeAddress)
#Html.Partial("Address", Model.WorkAddress)
but what happens is instead of the fields having names like HomeAddress.Street, HomeAddress.City etc. they just have the regular field names Street, City, etc. so the binder on the HTTPPost action has no idea what to do with them
Thanks in advance
Partial views where not designed to handle that scenario. What you are looking for are sub-editors. Take a look at Brad Wilson's excellent series on editor templates: http://bradwilson.typepad.com/blog/2009/10/aspnet-mvc-2-templates-part-1-introduction.html
Instead of Partial you use the EditorFor and related methods:
#Html.EditorFor(m => m.HomeAddress)
You can then use the auto-generated templates or define your own using an approach similar to partial views.
I have an action that depends on a list of integers. My first instinct was to simply declare the action with a List.
I tried declaring the action in the controller as:
public ActionResult EditMultiple(List<int> ids)
and in my View call like so:
<%= Html.ActionLink("EditMultiple", "EditMultiple", new { ids = new List<int> {2, 2, 2} })%>
Although it compiles the List is empty when I put a breakpoint in the action. Anybody know why or have an alternate approach?
Adding more detail about the scenario:
I'm trying to "Edit" multiple entities at the same time. I'm already at the point where I have an application that allows me to create/edit/view information about books in a library. I have a partial view that allows the user to edit information about a single book and save it to the database.
Now I'd like to create a View which allows the user to edit the information about multiple books with a single submit button. I've created an action EditMultiple which just renders the partial for each book (my model for this view is List) and adds the submit button afterwards.
Yes. The default model binder can bind "ids" to any ICollection. But you have to submit multiple parameters with the same name. That eliminates using the helper method "ActionLink". You can use url helper Action and append the ids to the link like so:
Test link
Here's the link from Haack's block.
I dont think
new List<int> {2, 2, 2}
gets properly converted into an POST that is bindable, you want to send
Ids=1&Ids=2&Ids=3
a comma separate list may also work, im not sure, i don't use the crappy default modelbinder.
Why are you doing that anyway? I hope thats pseudocode for something else...
I have an asp mvc 2 app lication where I want to display a list of check boxes that a user can select, based on a list of records in a database. To display the list my model contains a List object and the view has a foreach, and outputs Html.CheckBox for each item in the list.
Is there a way to get the model populated with the selected checkboxes, given that the model can't have specific properties for each checkbox, because the list is dynamic? Or do I have to manually iterate through the forms variables myself?
Edit: Extra details as per sabanito's comment
So in a simple view/model scenario, if my model had a property called Property1, then my view outputted a Textbox for Property1, when the form is posted via a submit button, the mvc framework will automatically populate a model with Property1 containing the text that was entered into the textbox and pass that model to the Controllers action.
Because I am dealing with a dynamic list of options the user could check, I can't write explicit boolean properties in my model and explicitly create the checkboxes in my view. Given that my list is dynamic, I'm wondering if there are ways to create my model and view so that the mvc framework is able to populate the model correctly when the form is posted.
Here's what I would do:
Are you having any issues generating the checkbox's dynamically?
If not, create a property on your ViewModel that is a:
public List<string> CheckboxResults { get; set; }
When you generate your checkbox's in the view make sure they all share the name = "CheckboxResults". When MVC see's your ViewModel as a parameter on the action method it will automatically bind and put all the "CheckboxResults" results in the List (as well as your other ViewModel properties). Now you have a dynamic List based on which checkbox's your user checked that you can send to your DomainModel or wherever.
Pretty cool stuff. Let me know if you're having issues generating the checkbox's dynamically, that's kind of a seperate issue than model binding to a list.
Use a ViewModel that reflects your view exactly, and map your domain model(s) to the viewmodel.
At first it often seems appropriate to use domain models directly in the view, for no better reason than that they're simple to use. However, as the view gets more complex over time, you end up putting a TON of conditional logic in your view, and end up with spaghetti. To alleviate this, we typically create a ViewModel that correlates 1:1 with the view.