Bizzare behavior of MVC Action/RenderAction, ajax post, and Partial Views - c#

So the design ideal is to have one page with a couple different 'widgets' in this MVC app. Each 'widget' should be able to submit information back to itself and reload only itself. Simple in web forms, not so much with MVC it seems
First, we have our main page controller, nothing special
public ActionResult Index()
{
return View();
}
Next, we have our main page View. Note that I have tried both Action and RenderAction and there is no change in behavior
#Html.Action("Index", "Monitor", new { area = "Statistics" });
<div id="messages">
#Html.Action("Index", "Messages", new { area = "Data"});
</div>
#section Script {
<script src="#Url.Content("~/Scripts/jquery-1.9.1.min.js")" type="text/javascript"></script>
<script type="text/javascript">
$('#filter').click(function () {
$.ajax({
method: 'POST',
url: '#Url.Action("Index", "Messages", new { area = "Data"})',
success: function(data){
$('#messages').html(data);
}
});
return false;
});
</script>
The Index ActionResult in the Messages Controller:
public ActionResult Index()
{
var model = GetMessages();
return PartialView(model);
}
For the sake of brevity, going to skip the whole of Monitor Index View, and only give a brief version of Messages Index View
#using (Html.BeginForm("Index", "Messages", FormMethod.Post))
{
//Some fields to limit results are here, with style classes
<button type="submit" id="filter">Filter</button>
}
#foreach(var item in Model)
{
//Display results
}
Upon loading the main page, all looks good. The fields to limit results are displayed, as well as messages. I can enter something into the fields, click Filter, and am returned to the main page but! ...the fields have lost their style classes and the messages are unfiltered.
Strange, but more strange is if I again enter information in the fields and click Filter, this time I am not taken to the main page, but get only the Partial View of the Messages Index displayed and the messages are not filtered.
I can't say that the filtering not working is related to this issue or not, but the non-consistent behavior of clicking Filter is the part that bothers me. Anyone like to point out what I am doing wrong in here?

You probably should be using Ajax.BeginForm rather than Html.BeginForm in your widgets. That will let the widgets manage their own posts:
<div id="messages">
#using (Ajax.BeginForm("Index", "Messages", new AjaxOptions { UpdateTargetId = "messages" }))
{
// fields content
}
// other widget content
</div>
The "bizarre" behavior you're seeing is happening because on page load the submit event for your #filter button is being hijacked using jQuery, but after the first replacement of the widget content the #filter submit event is no longer being hijacked so when you click it the whole page is submitted. If you don't want to use Ajax.BeginForm you'll need to use $.on rather than $.click to sign up events, as it will handle events for matching elements which are created after the event sign up script has run.

Related

MVC Render section scripts in controller

I would like to render the "scripts" section of the .cshtml view inside the controller as a string. Is this possible?
What I actually want to do is get the scripts with a separate ajax call and then run eval on the script after loading the html of the view also with ajax.
I've tried looking for related topics but haven't come up with anything relevant. Some related answers fool around with HtmlHelper.ViewContext.HttpContext.Items[""] but I'm unsure how to use it.
What I want is something like this: string scripts = GetScriptsForView(action, controller); which returns the section used in the view like this: #section Scripts {
To clarify (edit):
I'm trying to replace the "RenderBody()" of the layout page with ajax calls, so that I don't have to load the layout containing the static header every time.
I have managed to replace all <a>-tags with ajax calls replacing the <div> containing the view, but am unable to get the javascripts working.
I could remove the #section scripts { from the cshtml-files and let the script tag get loaded with the html view. The problem with this is that if I reload the page it calls the scripts for that view before calling the scripts of the layout page, resulting in errors. Therefore I wish to load the scripts separately.
TL;DR
While you can load sections and contents in separate requests (see example 1), but you don't need to do that. Instead:
You can have different Layout pages for different purposes and dynamically decide which layout to use for the view. For example a full layout page for normal requests and a simple layout page without headers and footers for ajax requests (see example 2).
You can decide dynamically about the layout page in _ViewStart.cstml or in the controller, based on different request parameters, like Request.Headers, Request.QueryString, Request.IsAjaxRequest, etc.
Long Answer
Here are some useful notes about the layout, section, view and partial view which may help you to handle the case:
Specify Layout in return View() - When returning a View you can specify the layout for the view. For example return View("Index", masterName: "_SomeLaypout"). You can have some logic to dynamically decide about the layout name.
Specify Layout in _LayoutStart.cshtml - When returning a View, you can specify the Layout in _ViewStart.cshtml file, for example #{ Layout = "_Layout"; }. You can have some logic to dynamically decide about the layout name.
Render content without Layout - When return a view using PartialView() method, it will render the whole content of the view without any layout or without rendering any section. It's equivalent to using return View and setting Layout to null, in _ViewStart.cshtml)
Render Section without any Content - You can have a layout having just a RenderSection method. Then if you return a view using that layout, it just renders the specified section of that view and will ignore the contents.
Scripts with/without Section - Considering above options, when you put scripts in the script tag without putting in a Section, you guarantee they will be returned as part of the result, regardless of calling return View or return PartialView or having or not having Layout. So in some cases you may want to put scripts without sections. In this case, when you load the partial view using ajax call, it contains the content as well as scripts of the partial view.
In some cases you may want to have some common content/scripts even for partial views, in such cases you can use Section, also have a Layout page which renders the section and contains common things that you want to have in all partial view. In this case you need to return the partial view using return View and specify that specific layout page.
Example 1 - Return just scripts or just content in an ajax request
The following example shows how you can send an ajax request to get content and send an ajax request to get scripts section.
Please note, I don't recommend using different requests for getting
content or getting scripts separately and this example is just for
learning purpose to show you what you can do with Layout pages and
_ViewStart.
To do so, follow these steps:
Change the _ViewStart.cshtml content to:
#{
if(Request.QueryString["Layout"]=="_Body")
{
//Just content of the page, without layout or any section
Layout = null;
}
else if (Request.QueryString["Layout"] == "_Script")
{
//Just script section
Layout = "~/Views/Shared/_Script.cshtml";
}
else
{
//Everything, layout, content, section
Layout = "~/Views/Shared/_Layout.cshtml";
}
}
Note: Instead of a Request.QueryString, you can easily rely on a Request.Header or Request.IsAjaxRequest() or ... base on your requirement.
Then just for _Script, add a new layout page named _script.cshtml having the following content:
#RenderSection("scripts", required: false)
Then:
To get the script section, send a normal ajax request and add the following query string: Layout=_Script.
To get the content without script section, send a normal ajax request and add the following query string: Layout=_Body.
To get the whole content, send a normal ajax request without specifying any Layout query string.
For example, assuming you have a Sample action in Home controller:
[HttpGet]
public ActionResult Sample()
{
return View();
}
Which returns the following Sample.cshtml view:
<div id="div1" style="border:1px solid #000000;">
some content
</div>
#section scripts {
<script>
$(function () {
alert('Hi');
});
</script>
}
In client side, to get the script section:
<button id="button1">Get Sample Content</button>
<script>
$(function () {
$('#button1').click(function () {
$.ajax({
url: '/home/sample',
data: { Layout: '_Script' },
type: 'GET',
cache: false,
success: function (data) { alert(data); },
error: function () { alert('error'); }
});
});
});
<script>
Example 2 - Return Content Without Layout Using Ajax requests
In this example, you can see how easily you can return content and scripts of the views without layout for ajax requests.
To do so, follow these steps:
Change the _ViewStart.cshtml content to:
#{
if(Request.IsAjaxRequest())
{
Layout = "~/Views/Shared/_Partial.cshtml";
}
else
{
Layout = "~/Views/Shared/_Layout.cshtml";
}
}
Add a new layout page named _PartialView.cshtml having the following content:
#RenderBody()
#RenderSection("scripts", required: false)
Get the view using ajax. For example, assuming you have a Sample action in Home controller:
[HttpGet]
public ActionResult Sample()
{
return View();
}
Which returns the following Sample.cshtml view:
<div id="div1" style="border:1px solid #000000;">
some content
</div>
#section scripts {
<script>
$(function () {
alert('Hi');
});
</script>
}
Get the result using ajax:
<button id="button1">Get Sample Content</button>
<script>
$(function () {
$('#button1').click(function () {
$.ajax({
url: '/home/sample',
type: 'GET',
cache: false,
success: function (data) { alert(data); },
error: function () { alert('error'); }
});
});
});
<script>
As per my understanding I guess you are looking for load the page via Ajax without reloading the entire page.
Did you check the Kool Swap Jquery plugin? Hope this will match your requirement.

Pass data from one view to another view -MVC

What would be the best method to transfer data from one view to another view? or is this bad practice?
The reason is that i want to display #model.count() from one view to the homepage, basically a summary of all the views on the homepage. There is tempdata, html.helper etc but id like to know the best and most reliable method. Thus avoiding problems further on down the line
here is the code in question
product.cshtml
<p>Total amount of Products = #Model.Count()</p>
i basically want that same value to display on the homepage
You'd have to refresh the homepage for the value to actually 'update.' At that point you may as well pass the value back in as a parameter, but I think that's not what you're hoping for.
It probably isn't the cleanest solution, but I would think you'd want your text on the main page to be settable via some javascript/jquery.
Main Page has this snippet:
<form id="PassBackVals"
<input type="hidden" name="ProductCount" value="0">
</form>
<script>$( ".ProductCount" ).change(function() {
$("$CurrentProductCount").text = $(".ProductCount").val;
});
</script>
and the Area displaying the text itself on the main would have something along the lines of
<p> I'm currently showing <div id="CurrentProductCount">0</div> Products </p>
Then in your product.cshtml, you'd have
<script>$(".ProductCount").val = #Model.Count()
$( ".ProductCount" ).change();
</script>
Ok i looked into other methods and resolved the issue by moving the code behind the viewbag into a public method below
[OutputCache(NoStore = true, Location = OutputCacheLocation.Client, Duration = 10)]
public ActionResult UpdateTotals()
{
JobController j = new JobController();
ViewBag.JobCount = j.JobCount();
ProductController p = new ProductController();
ViewBag.ProductCount = p.ProductCount();
return PartialView("UpdateTotals");
}
then i added the viewbags into a partial view and using setinterval() javascript,
<div id ="UpdateTotals">
#{ Html.RenderAction("UpdateTotals");}
</div>
<script>
setInterval("$('#UpdateTotals').load('/home/UpdateTotals')", 10000);
</script>
i was able to refresh the data constantly to my desire without the mess of pulling data through views via javascript.
hopefully this will help anyone in future :)

Ajax.BeginForm seems to redirect Action completion

I am currently developing a .net mvc 3 application. Here is the problem. For some reason, Though I am using Ajax.BeginForm and the right action is getting called, after the action completes, it is trying to redirect as if to another page that does not exist. However, I want it to stay on the same page just submit the form using ajax and return some friendly message to the user after the action completes.
Here is my Ajax.BeginForm page:
#using (Ajax.BeginForm("Action", "Controller", new AjaxOptions { HttpMethod = "Post" }))
{
<div id="lnkContainer">Update </div>
#Html.TextAreaFor(m => m.Message, new { style = "width:575px" })
}
Here is my Action:
[Authorize]
[AcceptVerbs(HttpVerbs.Post)]
public PartialViewResult Action(ActionModel actionModel)
{
database-related code
.....
database-related code
return PartialView();
}
I'm fairly certain your problem lies in onclick="javascript:document.forms[0].submit();". This will submit the form as a normal POST request. If you want to use the #Ajax.BeginForm helper, use a regular <input type="submit"> to trigger the submit. If you really need to use a link, then using #Ajax.BeginForm really doesn't matter because you will have to code submitting an Ajax request using jQuery, etc.
As far as Ajax.BeginForm and redirection is concerned, the form will revert to a normal HTML form in the event that the user has disabled javascript in their browser, or if your missing the appropriate scripts, etc.
I faced the same problem, I solved it by adding the below code in the BundleConfig.cs
bundles.Add(new ScriptBundle("~/bundles/jqueryajax").Include(
"~/Scripts/jquery.unobtrusive-ajax.js"));
and then the below code in _Layout.cshtml
#Scripts.Render("~/bundles/jqueryajax")

Asp.net mvc3 periodic refresh of results without reloading the page

I'm using asp.net MVC3 for a website that displays in a view a query result (managed in the controller) using a foreach.
What I want to do now is to automatically refresh the output of the query every tot time, without refreshing the page.
How can I do that using ajax?
This is the code of the View:
#{
string firstTime = "";
}
#foreach( var database in Model)
{
if (!(firstTime == database.DB))
{
<h3> #database.DB </h3>
}
<div class="logContainer" onclick="location.href='/logs/Details?databaseID=#database.DB&exceptionName=#database.Exception&exceptionsOccurred=#database.Count';">
<div class="counter"><b>#database.Count</b></div>
<div class="exceptionName"> Exceptions of Type: #database.Exception</div>
<div class="date">Siste: #database.LastOccurred</div>
</div>
<hr />
firstTime = database.DB;
}
You could use the window.setInterval javascript method to send AJAX requests to the server at regular intervals and refresh the corresponding part of the DOM. For example if you wanted to refresh the contents every 10 seconds:
window.setInterval(function() {
$.post('#Url.Action("someaction", "somecontroller")', function(result) {
$('#results').html(result);
});
}, 10 * 1000);
This will send an AJAX request to the controller action which in turn could return a partial view containing the updated results:
pubilc ActionResult SomeAction()
{
SomeViewModel model = ...
return PartialView(model);
}
The result of this partial view will then be injected into some DOM element with id="results".
You could either pass the query result using JSON and render the HTML yourself from javascript, or separate the for-each code to a different partial view, and using jQuery's $.ajax method change the query result's div html with the new response
Why not put your data in to an existing grid control such as DataTables, which is lightweight pretty fast and extensible. Then, using a javascript timer, tell the data table to refresh it's contents.
I've used this with MVC3 with great effect.

Paging data in MVC3 AJAX

For the site I'm currently working on, I have a list of products which I need to display in a paged list. The list needs to be used on several different pages, each of which has their own rules for how to retrieve their list of products. The list pages need to refresh with AJAX. I'm using LINQ-2-SQL to talk to the database, and MVC3/Razor as the view engine.
So far so good.
What I need help with is figuring out how to implement this. I'll explain what I've done so far, and what isn't working, and I hope someone can give me some direction of the best way to get this working, whether it be bug fixes, missing options, or a redesign. Note that the setup described above is immutable, but everything else can be altered.
For the first set of data, I have Index.cshtml. This will be a list of all products. There will be other sets (such as a list of all products in a category, but I can do the selection for that just fine), but this is the primary test case.
Currently, I have an object to represent the state of the grid: PagingData. The details of it aren't really important, but it takes an IEnumerable when first instantiated, it stores itself in HttpContext.Current.Session between requests, and it has a function that returns an IEnumerable of the products that are supposed to be on the current page. I tried it as an IQueryable<>, but that didn't work.
Currently, I am getting an IQueryable.ToList() and setting it as the data for a DataPager that's used as the Model of a Partial view called _ProductList.cshtml. _ProductList primarily consists of a pager control (another partial) and a foreach loop across the Model to display a partial for each Product.
_ProductList.cshtml:
#model PagingData
<script type="text/javascript">
$(function() {
$('#productList a.pagerControl').live('click', function() {
$('#productList').load(this.href);
return false;
});
</script>
<div id="productList">
#Html.Partial("_Pager", Model)
#foreach (var item in Model.ProductsOnPage)
{
#Html.Partial("_ProductListGridDetail", item);
}
</div>
_Pager uses: #Html.ActionLink(page.ToString(), "_ProductListSetPage", new { newPage = page }, new { #class = "pagerControl" }) to provide the links to change pages (the page variable is the number of the page to draw, from a loop).
This solution works, kindof. The problem I'm having with it is that the only way to update the PagingData with the new page is via a Controller, and each method of modifying the pager (page, # of products per page, format, sort) will need its own controller because I can't overload them. This also means _Pager produces URLs like http://localhost:52119/Product/_ProductListSetPage?newPage=3 instead of http://localhost:52119/Product.
I've tried Ajax.ActionLink(), and wrapping the whole thing in an Ajax.BeginForm(), but neither seemed to work at all. I do have the jquery.unobtrusive-ajax.js library included.
Is this approach feasible? Should I replace the PagingData object with something else entirely? I do not want the paging data in the URL if it's at all possible to avoid it.
If you don't want the page in the url you could use a <form> instead of link, like this:
#using (Html.BeginForm("Index", "Product")
{
#Html.Hidden("newPage", page)
<input type="submit" value="#page" />
}
Which should generate a form for each page with a hidden field containing the actual page number, for example:
<form action="/Product" method="post">
<input type="newPage" value="3" />
<input type="submit" value="3" />
</form>
Now all that's left is to AJAXify this form:
$(function() {
$('#productList form').live('submit', function() {
$.post(this.action, $(this).serialize(), function(result) {
$('#productList').html(result);
});
return false;
});
});
Which would invoke the Index action on ProductController:
public ActionResult Index(int? newPage)
{
var model = ... fetch the products corresponding to the given page number
return PartialView(model);
}

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