I am currently working with integrating a classic asp site with MVC3. I have some questions on some areas of the integration that I would like some feedback on.
Firstly, I have a asp page posting to an MVC controller action. I have very little scope to modify the asp page. I want to take the form fields posted from the asp page and map them in to a model object. The posted values have obscure names such as "my_name" which I want to map to Name property on the model object. Is the best way of doing this via a Model Binder or is there an alternative?
Next question I have is a follow on from the previous, I am concerned with any cross site scripting so want to check the values of the posted variables to be valid and contain no strange characters etc. Is there something built in to MVC3 that does this out of the box?
When the asp page posts to the controller action, I would like to show a waiting icon while the controller action is processing as the controller action could take 10 seconds plus as it must call external systems etc. Therefore I don't want the post to seem as its hanging. Is it possible to wire up the controller action to return a view with a waiting icon, while the main body of the action is processing in the background and once complete redirects to another page?
Is the best way of doing this via a Model Binder or is there an
alternative?
The best way of doing is a model binder. You can have a custom model binder to take care of the ASP scenario that maps the my_name to Name. Mostly you should have a separate action to handle the requests coming from classic asp and you can link the custom model binder to only this action.
Is there something built in to MVC3 that does this out of the box?
The request validation is enabled as default in MVC. So if an user tries to post a script block to the action MVC will throw exception. Of course you can switch off request validation by decorating the action with ValidateInput(false) if you need.
For long running actions you have to use asynccontrollers.
Related
I am using MVC and have a page like contact us. This page has a view and a controller with a action method create. That action method takes in a model and with that model it will add to a database and email users. Is there a way to lock down access to the controller meaning they need to use the view to get access to the controller action method create. I think people can find the model format and just keep hitting the controller. Something like antiforgerytoken but it’s not working in my application because of the classic mode. I get the message This operation requires IIS integrated pipeline mode.
In the application I'm developing in ASP MVC 3 I have the following scenario. I have some properties of the model that I wanna use after the page makes a request, however when the post request is done they arrive as null since they are not bound to any control in the view form.
For what I've read this is the expected behaviour of ASP MVC and people recommend to use a #Html.HiddenFor() to be able to receive them, but I don't want this information to be available to user in case he selects "View source" from the browser.
In JSF I remember that you could use the #ViewScope annotation for this scenario, but is there something similar in ASP MVC? For what I've read saving them in the ViewData property will not work either and I do not want to use the Session because this properties will only be relevant in this particular view.
If I understand your question correctly, you may be looking for something like TempData.
You can read about it here:
http://blogs.teamb.com/craigstuntz/2009/01/23/37947/
A more recent post can be found here:
http://codeoverload.wordpress.com/2011/05/29/controller-tempdata-in-asp-net-mvc-3/
I am learning ASP.NET MVC, and ran across a video on the asp.net/mvc website that showed how to retrieve a value from a textbox after a postback. In the video the author simply grabs the value from the Request object in the controller.
It seems like this breaks the separation of concerns concept? By doing this the controller is now dependent upon the presence of a Request object which won't exist if one runs unit tests against the controller.
So I assume this is an incorrect way of retrieving form data on a postback. What is the correct way? Once I am in my controller, how do I get access to the postback data?
It seems there should be some intermediate step that essentially pulls the data from the postback and packages it into a nice object or some other format that the controller would then used?
The data should be posted back to your Model or ViewModel. Your controller method that handles the POST will expect the model to be provided as a parameter.
Here is a blog entry that gives an example
Using model binding, MVC can populate data coming from the form data, the query sting, cookies, and a number of other sources directly into your object model or other paramters defined as parameters to your action methods in the controller.
There's too many details of how this works to summarize here, but it is the cornerstone of the power of ASP.NET MVC.
Check out Models and Validation in ASP.NET MVC as a good starting point. You'll find tons of other resources around MVC model binding out there.
I've really liked Steven Sanderson's Pro ASP.NET MVC 2 Framework if you prefer physical books.
This may be a stupid question, but anyway... I have an MVC site and a legacy ASP.net web forms site. I have a controller action on my MVC site that I would like to (programatically) POST to from my web forms site.
I can find lots of information describing RESTful services etc., but I can't seem to find a resource that explains how to do this bit - anybody point me in the right direction?
In MVC, there is nothing special about the FORM on the page (unlike WebForms).
Just create a normal HTML FORM (without runat="server"). Set the action to point to your controller action. Set the method to POST.
That's it. In your controller action, you can access the FormCollection directly, or you can attempt to use parameter/model binding.
This post demonstrates how to post data to web server with HttpWebRequest.
You just need to compose your own data to be posted, and change the url that the data will be posted to. It's the url of your controller in your case.
I'm trying to work out if there's a built in way in ASP.NET MVC to assign the form values that are POST'd back to the properties of the ViewModel that was originally sent to the View?
So I'm thinking along the ideas of decorating some of the properties in the ViewModel with an attribute and then reflecting over the ViewModel and using that name to extract values (and coerce) from the Form[] object.
However, I'd imagine that something like this was already built in and so don't want to re-invent the wheel here.
The problem that I'm trying to solve is that a user clicks a button on a form and the server validates the data and if there are errors we return the user to the form by using the same ViewModel to carry the data and thereby fill the values back into the form that the user originally entered.
(Yes, I'm also doing client side validation using JavaScript to make this lightweight but for security I have to repeat validation on the server.)
Ideas?
You can use UpdateModel or TryUpdateModel in your controller.
I recommend using one of the overloads in which you specify the fields to be updated.
This is discussed in detail on page 78 of the Wrox Professional ASP.net ebook (or echapter!)
I don't think MVC has anything like this built in, or at least I haven't seen anything. It would be nice though as many other MVC frameworks do this (struts for example).