I am using MVC 3 with ASP.NET. I have a dropdown box and getting it populated from database. I am using validation on the View. If it fails the validation, I am displaying the same view with errors being caught in ViewDate.ModelState.AddModelError.
I am checking for the ViewData.Modelstate.IsValid property if true then execute the code else display the errors in the view.
It is diplaying the errors in the page, but the selected value in the drop down is getting reset when validation fails.
How do I make sure the seleceted drop down does not change when validation fails?
In the action that handles the form submission and validation, make sure you set the properties on your model object from the form before rendering the form view.
For example, in this question you can see how the Dinner object parameter in the Create action is reused when the View() is returned.
Set a breakpoint in the action handling the submission and check the property for the list of values. If it's null or empty reload it.
If your dropdownlist is being populated via javascript then it is possible that the property holding the list of values is empty on submission. This is common when using cascading dropdownlists such is the case with loading Province / State lists based off country. All cascading lists loaded after the model has been passed to the view must be reloaded using the selected value of for each dropdownlist in the controller action that is handling the submission.
Related
I'm currently using Oracle APEX. I have this validation that executes error message whenever an item is null. And I have created a dynamic action when losing focus, it formats into a currency format.
I have this problem whenever I submit the page, my item becomes null / my validation executes.
My assumption is that validation comes first before the dynamic action.
Validation
Item is not null
Dynamic Action
Lose Focus
Action
Execute PLSQL that formats to a currency value.
Scenario:
Fills-up an item
Click submit button ahead
Expected Result:
Empty validation should not trigger when page is submitted.
Actual Result:
Empty validation is triggering when page is submitted.
Try this set you offending validation to never and make sure the dynamic action is doing what you want. Oracle in general is klugy with number formatting.
I have a wicket page with a couple of TextFields that have different kind of validators. So far, validation is triggered via Ajax on the onChange event.
I also have a checkbox that defines which set of validation rules should be used for the TextFields.
If I click the checkbox and then input data into the TextFields, validation works just fine. But how do I handle the fact that already entered and validated data can suddenly become invalid if the checkbox is clicked afterwards? How do I trigger the validation and the redraw (to show the error notification) of the TextFields from within an AjaxEvent from the checkbox?
I tried to call myTextField.validate() but that didn't trigger any of my validators.
Since your validation is based on multiple components you should implement IFormValidator. Pass both checkbox and textfield in getDependentFormComponents() and change of either will trigger it.
Also if you are using checkbox to refresh some elements make sure to use AjaxCheckbox, that has onUpdate(AjaxRequestTarget) method.
You could attach an AjaxFormSubmitBehavior in the checkbox. This would submit the form and trigger validation each time the checkbox value is toggled.
I am currently working on a project in MVC 3 where I am leveraging Entity Framework to persist one data model over two Views which each contain one HTML Form (similar to wizard-based design).
Yet after the user fills out the appropriate fields on the first View and submits the form, client-side validation for the entire model is triggered, and validation errors are shown for fields that will not even be available for input until the second View instantiates.
I have currently implemented a workaround where I simply turn off client-side validation for the first View entirely, but I am certainly not keen on the idea of populating my model with data that has not been validated at all. This is bad. M'kay.
Is there any way to partially validate the fields on the first View and not trigger valdiation for the whole data model?
That's where ViewModels comes. Instead of directly binding the domain model with the views, you should create view models over them and bind to the views.
If you are not required to put validation on the EF models directly then you can use the MetadataType to do partial validation as needed. Take a look at my long example here on stackoverflow.
Thanks for the input all. However, I was able to obtain a solution in a very simple way. By placing the following code in the HttpPost element of the first View...
if (ModelState.IsValidField("FirstField") && ModelState.IsValidField("SecondField"))
return RedirectToAction ("NameOfAction", model);
else
return View();
...I was able to achieve partial field validation. However, this field-specific approach will ONLY work provided the Submit button on the first View has class "cancel" and the additional validation errors that are generated (for the fields that are NOT present on the first View) are manually cleared before the above if statement. To do this, use:
ModelState["FieldName"].Errors.Clear();
No major change in architecure. No partial Views. No handing off unvalidated Data.
Works very well...
NOTE: If the second View loads with validation errors, use:
ModelState.Clear();
in the Action where the second View is initially called. This will make the second View load clean and error free, while still showing the validation errors later upon final form submission.
I have a form that only has a checkbox. If the checkbox is not checked then the page won't be valid and won't submit the data. On the view I have out putted some fields from the model object, just to let the user know what they are deleting. When I click the Submit button and the model state is not valid the page will show the validation error but the data from the model is no longer there!
Does anyone know how I can persist this data without making another call to the database to populate the model object?
Thanks
ASP.Net MVC will not magically persist model info.
You need to either include it in hidden fields in the form (which an attacker can modify), or re-fetch it from the database.
If you don't repopulate the Model from the DB, you have to postback all the data, using hidden fields for example.
Anyway, I don't understand how the model validation could fail, being just a checkbox :/.
I have a view with a form..this form has a textbox and a checkbox in it.
i also have a submit button in the form which points to an action in a controller.
my question is..how can i pass the values in the textboxes and the checked state of the checkboxes to the controller action?
the textboxes and checkboxes are not tied to a model.
thanks
You have two options.
The best option would be to create a ViewModel. This model doesn't need to have any logic or anything behind it, just a public get/set for the properties. This means you can also use the MVC validation, helpers and binding on the values and makes it easier to work with.
The alternative is for your action to accept a FormCollection, this is basically a dictionary with the form values, the keys being the name attribute on your form elements.