I am making an Ajax call and adding content to a form inside a MVC2 app.
I need to update the Client Validation Metadata with the validation for my new content.
<script type="text/javascript">
//<![CDATA[
if (!window.mvcClientValidationMetadata) { window.mvcClientValidationMetadata = []; }
window.mvcClientValidationMetadata.push({"Fields":[{"
...
</script>
Is there a way to generate this metadata for a partial view ?
Thanks in advance.
I was banging my head against a wall for a few days on this too and was going to go down the route of removing the form tag, but have just got it working in a slightly less hacky way if you are still interested. My scenario was similar in that I have a form with a collection of elements to validate initially, but users can dynamically add new rows via ajax.
I'll break it down so hopefully it'll be easier to see what is going on. Looking at the MVC source code, the form and validation works roughly as so:
Html.BeginForm() outputs the opening form tag then creates and returns a new instance of MvcForm, which doesn't outwardly do much except make the scope of the form easier to manage for you.
It does however create a new FormContext and stores this within ViewContext.FormContext. It is this FormContext that tracks the client validation.
The last thing Html.BeginForm() does is set the FormId property of the new FormContext, using the id of the form tag. This is required so the client script can match up forms and validation rules.
Html.EndForm() disposes the MvcForm. This Dispose method outputs the form closing tag and then calls ViewContext.OutputClientValidation() which is resposible for outputting the javascript. Lastly it removes the current FormContext and sets it back to the parent FormContext or null if there isn't one.
So to not output the form tag we somehow need to take some of the FormContext management out of the MvcForm constructor/destructor.
So within my Partial View I did the following:
At the top I check if the ViewContext.FormContext has a value. If so we we are in the initial load so no need to mess around. If not, it is an ajax call, so I enable client validation, create a new MvcForm directly (not with BeginForm) - this causes a FormContext to be created - and set the FormContext.FormId to the same as my parent page
At the end of the view, I check if I have a form instance and if so, call ViewContext.OutputClientValidation() and reset the ViewContext.FormContext to null. I do not Dispose() the MvcForm as this would output the closing tag and MvcForm does not contain disposable objects.
The skeleton of the view looks as so:
<%
MvcForm dummyForm = null;
if (this.ViewContext.FormContext == null)
{
Html.EnableClientValidation();
dummyForm = new MvcForm(this.ViewContext);
this.ViewContext.FormContext.FormId = "mainform";
}
%>
// standard partial view markup goes here
<%
if (dummyForm != null)
{
this.ViewContext.OutputClientValidation();
this.ViewContext.FormContext = null;
}
%>
You could quite easily wrap this up into an extension method
Phil
Finally got it to work.
The answer is simple: don't waist time with MicrosoftMvcValidation.js. It is generated with Script# which makes it difficult to extend.
Switch to xVal and jQuery Validation.
It doesn't need a form to generate the client validation metadata.
Also in order to load validation for a AJAX request all you have to do is to call the following after you have the new Html:
lForm.find("#placeholder").empty();
lForm.valid();
lForm.find("#placeholder").html(responseHtml);
That does it. First you remove the old content. Than re-run validation to get rid of potentially obsolete validation errors. Than add the new content. Works like a cham.
Also jQuery Validation makes it really easy to enable or disable validation for a certain field (conditional validation).
I have the same problem and resolve using the Future files, and in MicrosoftMvcJQueryValidation.js I change the and of file, this:
$(document).ready(function () {
var allFormOptions = window.mvcClientValidationMetadata;
if (allFormOptions) {
while (allFormOptions.length > 0) {
var thisFormOptions = allFormOptions.pop();
__MVC_EnableClientValidation(thisFormOptions);
}
}
});
for:
function chargeValidation() {
var allFormOptions = window.mvcClientValidationMetadata;
if (allFormOptions) {
while (allFormOptions.length > 0) {
var thisFormOptions = allFormOptions.pop();
__MVC_EnableClientValidation(thisFormOptions);
}
}
}
and in content after close form using I call the 'chargeValidation()', this resolve for me the problem I have using $.get(action) containing a form validation.
I hope to help you!
Finally found it.
After content is loaded in dynamically you will need to register the new form.
Since I am using Facebox, I added it to the facebox code, however you can add it wherever you need, or in a callback if your modal or whatever you are loading into has an afterLoaded event.
I wrapped them in a try/catch just in case i ever use facebox without the validation stuff.
Just run these two lines AFTER your content has been loaded:
try {
Sys.Application.remove_load(arguments.callee);
Sys.Mvc.FormContext._Application_Load();
} catch (err) {/* MVC Clientside framework is likely not loaded*/ }
I made some progress but I am not quite happy.
Problem #1: The client validation metadata is not generated unless you have a Html.BeginForm() in your partial. Which in my case is false because I do not update the entire form, I update portions of it.
Solution for Problem #1: Add a form in the partial view, let MVC generate the client validation MetaData and remove the form tags with a action filter. Let's call this Hack #1.
public class RemoveFormFilterAttribute : ActionFilterAttribute
{
private static readonly MethodInfo SwitchWriterMethod = typeof(HttpResponse).GetMethod("SwitchWriter", BindingFlags.Instance | BindingFlags.NonPublic);
private TextWriter _OriginalWriter;
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
_OriginalWriter = (TextWriter)SwitchWriterMethod.Invoke(HttpContext.Current.Response, new object[] {new HtmlTextWriter(new StringWriter())});
}
public override void OnResultExecuted(ResultExecutedContext filterContext)
{
if (_OriginalWriter != null)
{
HtmlTextWriter lTextWriter =(HtmlTextWriter) SwitchWriterMethod.Invoke(HttpContext.Current.Response, new object[] {_OriginalWriter});
string lOriginalHTML = lTextWriter.InnerWriter.ToString();
string lNewHTML = RemoveFormTags(lOriginalHTML);
filterContext.HttpContext.Response.Write(lNewHTML);
}
}
Problem #2: The initial client validation metadata for the page is gone by the time I have the metaData for the new content.
Solution for Problem #2: Store the initial metadata (hard copy) and update it with the new fieds, than call the methods you mentioned to let MVC know new stuff arrived. Let's call this Hack #2.
<script type="text/javascript">
var pageMvcClientValidationMetadata;
$(document).ready(function() {
$("input[name='PaymentTypeName']").change(PaymentTypeChanged);
//create a back-up of the ValidationMetadata
pageMvcClientValidationMetadata = JSON.parse(JSON.stringify(window.mvcClientValidationMetadata));
});
function PaymentTypeChanged() {
var selectedPaymentType = $("input[name='PaymentTypeName']:checked").val();
$.ajax(
{
url: 'PersonalData/GetPaymentTypeHtml?&paymentType=' + selectedPaymentType,
type: "GET",
cache: false,
success: GetPaymentTypeHtml_Success
});
}
function GetPaymentTypeHtml_Success(result) {
$('#divPaymentTypeDetails').html(result);
UpdateValidationMetaData();
}
function UpdateValidationMetaData() {
//update the ValidationMetadata
for (i = 0; i < window.mvcClientValidationMetadata[0].Fields.length; i++) {
pageMvcClientValidationMetadata[0].Fields.push(window.mvcClientValidationMetadata[0].Fields[i]);
}
//restore the ValidationMetadata
window.mvcClientValidationMetadata = JSON.parse(JSON.stringify(pageMvcClientValidationMetadata));
//Notify the Validation Framework that new Metadata exists
Sys.Application.remove_load(arguments.callee);
Sys.Mvc.FormContext._Application_Load();
}
Now. Any improvements would be appreciated.
Hack #1: How can I generate the client validation metadata without having an actual form ?
HAck #2: How can I appent to the page validation metadata ?
Related
As far as I can tell, Backbone.js view represents DOM element. I take it from existing DOM or create it on the fly in el attribute.
In my case, I want to take it from server with AJAX request because I'm using Django templates and don't want to rewrite everything to JavaScript templates.
So I define el function that performs AJAX request.
el: function() {
model.fetch().success(function(response) {
return response.template
})
}
Of course, it does NOT work because AJAX request is executed asynchronous.
This means that I don't have el attribute and events does NOT work neither. Can I fix it?
Maybe the Backbone.js framework isn't the right tool for my needs? The reason I want to use that was to have some structure for the code.
P.S. I'm new to Backbone.js.
Do your ajax request from another view, or directly after the page load using jquery directly, and after you've downloaded your template, THEN instantiate your backbone view class with the proper id/el or whatever (depending on where you stored your ajax fetched template). Depending on your use-case, this may or may not be a sensible approach.
Another, perhaps more typical approach, would be to set up your view with some placeholder element (saying "loading" or whatever), then fire off the ajax, and after the updated template has been retrieved, then update your view accordingly (replace the placeholder with the actual template you requested).
When/if you update your view with new/other DOM elements, you need to call the view's delegateEvents method to rebind your events to the new elements, see:
http://backbonejs.org/#View-delegateEvents
I came across a similar requirement. In my instance, I was running asp.net and wanted to pull my templates from user controls. The first thing I would recommend is looking into Marionette because it will save you from writing a lot of boiler plate code in Backbone. The next step is to override how your templates are loaded. In this case I created a function that uses Ajax to retrieve the HTML from the server. I found an example of this function where they were using it to pull down html pages so I did a little modification so I can make MVC type requests. I can't remember where I found the idea from; otherwise, I would give the link here.
function JackTemplateLoader(params) {
if (typeof params === 'undefined') params = {};
var TEMPLATE_DIR = params.dir || '';
var file_cache = {};
function get_filename(name) {
if (name.indexOf('-') > -1) name = name.substring(0, name.indexOf('-'));
return TEMPLATE_DIR + name;
}
this.get_template = function (name) {
var template;
var file = get_filename(name);
var file_content;
var result;
if (!(file_content = file_cache[name])) {
$.ajax({
url: file,
async: false,
success: function (data) {
file_content = data; // wrap top-level templates for selection
file_cache[name] = file_content;
}
});
}
//return file_content.find('#' + name).html();
return file_content;
}
this.clear_cache = function () {
template_cache = {};
};
}
The third step would be to override Marionette's method to load templates. I did this in the app.addInitializer method. Here I am initializing my template loader and setting it's directory to a route handler. So when I want to load a template, I just set the template: "templatename" in my view and Backbone will load the template from api/ApplicationScreens/templatename. I am also overriding my template compiling to use Handlebars because ASP.net is not impressed with the <%= %> syntax.
app.JackTemplateLoader = new JackTemplateLoader({ dir: "/api/ApplicationScreens/", ext: '' });
Backbone.Marionette.TemplateCache.prototype.loadTemplate = function (name) {
if (name == undefined) {
return "";
} else {
var template = app.JackTemplateLoader.get_template(name);
return template;
}
};
// compiling
Backbone.Marionette.TemplateCache.prototype.compileTemplate = function (rawTemplate) {
var compiled = Handlebars.compile(rawTemplate);
return compiled;
};
// rendering
Backbone.Marionette.Renderer.render = function (template, data) {
var template = Marionette.TemplateCache.get(template);
return template(data);
}
Hopefully this helps. I've been working on a large dynamic website and it is coming along very nicely. I am constantly being surprised by the overall functionality and flow of using Marionette and Backbone.js.
Trying to put some pieces together here.
Piece 1: I know that I can get the current username in MVC by using:
#HttpContext.Current.User.Identity.Name
in my razor view.
Piece 2: I have some MVVM-style code in a separate JS file, relevant parts shown below:
var FeedbackViewModel = function () {
var self = this;
self.username = ko.observable("");
self.feedbackText = ko.observable("");
self.userNameCaptured = ko.computed(function () { return self.username().length > 3; }, self);
};
var feedbackViewModel = new FeedbackViewModel();
ko.applyBindings(feedbackViewModel, document.getElementById("feedbackModal"));
Question: How do I pass the current username from MVC3 to the Knockout viewModel so that I can observe and take action based upon it?
I assume feedbackViewModel is defined as a global variable, so you could simply add some code to the CSHTML file to populate it inline:
<script type="text/javascript">
feedbackViewmodel.username("#HttpContext.Current.User.Identity.Name");
</script>
Another option would be to pass the variable into the ViewModel function as a constructor element.
(I'd rather post this as comment than answer but somehow don't have option here)
I've faced similar problems in the past (handoff between razor and javascript). The best answer I've found is to create a hidden control (#hiddenval or #username) which can then be "read" by a JQuery selector.
This approach works for me every time. It's inelegant and may potentially expose info to a user sourcing the html...
if it's not obvious, #HttpContext.Current.User.Identity.Name should be populated as part of the markup
Using MVC2 I have created a form using the Ajax helper in a view. The form posts to a controller which binds to a model object. A PartialViewResult is returned by the controller and the HTML gets updated into a div. So far, so good.
I now need to submit the same form and return the results in a generated file for the user to download. Obviously I don't want the file contents going into my div.
Is there an elegant way to handle this situation without having to hack it to bits? I'm fairly new to MVC / AJAX and it's still a point of confusion for me.
You may not use ajax call to download files. Following links may help you to do what you are trying to do
JQuery Ajax call for PDF file download
http://forums.asp.net/t/1683990.aspx/1
OK, so I couldn't find any simple solutions anywhere so I came up with my own. I remove the Ajax event handlers from the form when I want the download, put them back when I want the Ajax. I'm guessing there's a more elegant way to do this, as this feels like a 'clever trick'. I'm open to better suggestions but so far this is my preferred method.
Reference ToggleAjax.js on my page:
var ToggleAjax = function ($, form) {
var onclick = form.onclick,
onsubmit = form.onsubmit;
$('input[class*="ajax-enabled"]').click(function () {
form.onclick = onclick;
form.onsubmit = onsubmit;
});
$('input[class*="ajax-disabled"]').click(function () {
form.onclick = function () { };
form.onsubmit = function () { };
});
};
Then I call ToggleAjax on my page and pass in the form:
$(function () {
ToggleAjax($, $('form')[0]);
});
And of course I add the class ajax-enabled or ajax-disabled to the input controls.
I'm coming to a part in my MVC 3 page where I need to do a JQuery $.Ajax callback, but unlike before where I have returned some simple values and handled updating the UI using JQuery I need to refresh the part of the page that displays the main ViewModel data. So in effect it's almost as if I need to do a callback but instead of returning the JSonResult I want to return the original View?? I'm pretty sure though that I need to be thinking about using partial views? Could anyone advise or perhaps point me towards a good tutorial?
Thanks in advance.
If I understand correctly. In this sort of scenario I usually re-use the same action but return either a full or partial view based on the IsAjaxRequest method.
public ActionResult MyAction(string someParam)
{
//...
if (Request.IsAjaxRequest())
{
return PartialView(model);
}
else
{
return View(model);
}
}
This can then be called in jQuery using something like:
$("a.myAction").click(function (event)
{
event.preventDefault();
var button = $(this);
// Get more results using ajax
$.get(button.attr("href"), function (data)
{
// Add the new content
$('div#myActionResult').empty().html(data);
}, "html");
}
You may need to POST instead or change the Url to include a query string if you want to send data to the action to change the view.
I have a Partial View that renders WebGrid. My controller looks like
public ActionResult Index()
{
return View();
}
public ActionResult GetUserList(int? page, string sort, string sortdir)
{
var model = UserModel.getList(page,sort,sortdir);
return PartialView("_UserList",model);
}
Index.cshtml :
....
#Html.Action("GetUserList")
The problem is that every time I click on grid navigation or sort links it calls Index method. How can I make Webgrid to execute a different action (GetUserList in this case)? I'm sure I can prepend GetUserList to all links in grid using jquery, but I believe it should be a better way.
It's also possible that what I'm doing is completely wrong, so thanks for your suggestions.
After lot of monkeying around and digging (and even fiddling with Reflector with WebGrid's source code), I came to the conclusion that with WebGrid, you cannot control/change the Header link action.
To create the header link URL, the path is taken from HttpContext.Request.Path, so there is no way to customize it to point to a different route.
One very ugly hack would be to tap into to jQuery Ajax's events (since the header link uses jQuery.load to sort) and overwrite the URL:
Album Id
Better solution would be to use:
Telerik Grid which lets you specify custom routes and also offers much more flexibility in rendering your layout
or MvcContrib Grid (not sure if this lets you modify header links but definitely offers more flexibility than WebGrid)
#MrChief had the idea above about the ugly hack...I put that together. Here is the main code that I used to do this. It does, indeed, hijack the ajax call before it is put on the wire. The key is to modify the URL that is getting sent because the grid will grab that URL from HttpContext.Request.Path. and plug it into the onclick for the anchor element.
I put this into my main common.js and will simply attach a function to capture the ajaxSend event which happens just before the data is sent.
// Used to hijack the sending of all AJAX calls. Before it sends the call to the server, it checks to see if the
// active element (the element that prompted the call) is marked with a given class. If so, then it will perform
// the given operation.
$(document).ajaxSend(function (event, jqXHR, ajaxOptions) {
var activeElement = document.activeElement;
if ($(activeElement).attr('redosorturl') != null) {
// If this is a sort anchor link from a grid that needs to have the sort link redone, do it here.
// the code is in the eipGrip.js file.
if ($(activeElement).attr('redosorturl').toString() == 'redoSortURL') {
var newURL = RedoGridSortURL(activeElement, ajaxOptions.url.toString());
ajaxOptions.url = newURL.toString();
}
}
return false;
});
When rendering the page, I have marked the tag in column header that contains the incorrect URL with a class named "redosorturl', so I know when I hijack the ajax call, the operation has to be done on this element. I then call a custom function that gives me the correct URL, then the ajaxOptions.url is then rewritten with that new URL.
I have to pass the activeElement to that rewrite function so I can traverse up the DOM to get the grid information, where I have put data like the controller and action method that is used along with and IDs and other info that I use for the URL. Likewise, I pass in the current url string because the grid will inject a token at the end of the url that I parse off and put on the new url.
Your conclusion isn't right. You just need to wrap your webgrid in a Get form:
using (Html.BeginForm("GetUserList", "ThingaMaBob", System.Web.Mvc.FormMethod.Get))
{
var grid = new WebGrid(
...
));
Html.Hidden(grid.SortFieldName, grid.SortColumn);
Html.Hidden(grid.SortDirectionFieldName, grid.SortDirection == SortDirection.Ascending ? "ASC" : "DESC");
}
The hiddens are so that the sort dir and sort field end up in parseable form in the querystring. You end up with urls like localhost/ThingaMaBob/GetUserList?someotherfields=whatever=&sort=city&sortdir=ASC
If you remove [HttpPost] attribute and let the route come to the same function. you'll find the Request["page"] value in your method. this will allow you to put a check on Request["Page"] value.