I need to implement pagination. In controller, I ma just returning json data. View is purely client side development, MVC helpers are not implemented. View is done fully with jquery. Parameters are passed to controller through Ajax call and I am returning json data based on parameters by filtering data. How to implement pagination in this case?
Thanks
As example https://learn.microsoft.com/en-us/aspnet/mvc/overview/getting-started/getting-started-with-ef-using-mvc/sorting-filtering-and-paging-with-the-entity-framework-in-an-asp-net-mvc-application
you have specific problems?
Related
I am using ASP.NET MVC / WebAPI and Knockout to generate my views. I am trying to figure out where I should handle formatting, url generation, etc (I would normally do in my controller and return a view model).
Is is an ok practice to have my WebAPI return view models with preformatted data or should I leave that to the caller?
Please note the API is only used by my application
What I'd suggest is the following:
WebApi controller actions provide / consume data (json data) - Http verb actions
On your knockout viewmodel it contains methods to get / save etc the json data which is called on document ready to populate the data
The default mark-up is created by your MVC view returned from the controller on initial load and then any further can be done dynamically (either inline or templates; native or knockout)
In my opinion the WebApi should not return the full view model. It should only return the data consumed by your view model. The api points should not be implementation specific and allow for knockout consumption as well any other client.
HTH
I am new to MVC and I am continuing to learn more each day. I am converting and webform application to MVC for practice and wanted to know is there a way to call GET on a action and return json, array or whatever I want on document.ready function? I can do this using webapi, but I would rather do it using an action in the controller. I like the helpers that they Microsoft provides but they are for forms and action links, etc. Thanks for any help.
$(document).ready(function(){
$.ajax(Somehow call controller action here with data), success(function that returns json data)
});
I think this article has a great explanation with examples
http://www.codeproject.com/Articles/41828/JQuery-AJAX-with-ASP-NET-MVC
I am starting a new project, and keen to make use of the KnockoutJS + Web Api which are new to me, I have a good understanding of the Web Api, but Knockout is tough to get my head around at the moment.
This is my initial thoughts of how I want my app to work:
I have a standard MVC controller such as LeadsController
LeadsController has an Action called ListLeads, this doesn't actually return any data though, but just returns a view with a template to display data from Knockout.
The ListLeads view calls my api controller LeadsApiController via ajax to get a list of leads to display
The leads data is then mapped to a KnockoutJs ViewModel (I don't want to replicate my view models from server side into JavaScript view models)
I want to use external JavaScript files as much as possible rather than bloating my HTML page full of JavaScript.
I have seen lots of examples but most of them return some initial data on the first page load, rather than via an ajax call.
So my question is, how would create my JavaScript viewModel for Knockout when retrieved from ajax, where the ajax url is created using Url.Content().
Also, what if I need additional computed values on this ViewModel, how would I extend the mapped view model from server side.
If I haven't explained myself well, please let me know what your not sure of and I'll try and update my question to be more explicit.
I think your design is a good idea. In fact, I am developing an application using exactly this design right now!
You don't have to embed the initial data in your page. Instead, when your page loads, create an empty view model, call ko.applyBindings, then start an AJAX call which will populate the view model when it completes:
$(function () {
var viewModel = {
leads: ko.observableArray([]) // empty array for now
};
ko.applyBindings(viewModel);
$.getJSON("/api/Leads", function (data) {
var newLeads = ko.mapping.fromJS(data)(); // convert to view model objects
viewModel.leads(newLeads); // replace the empty array with a populated one
});
});
You'll want to put a "Loading" message somewhere on your page until the AJAX call completes.
To generate the "/api/Leads" URL, use Url.RouteUrl:
<script>
var apiUrl = '#Url.RouteUrl("DefaultApi", new { httproute = "", controller = "Leads" })';
</script>
(That's assuming your API route configured in Global.asax or App_Start\RouteConfig.cs is named "DefaultApi".)
The knockout mapping plugin is used above to convert the AJAX JSON result into a knockout view model. By default, the generated view model will have one observable property for each property in the JSON. To customise this, such as to add additional computed properties, use the knockout mapping plugin's "create" callback.
After getting this far in my application, I found I wanted more meta-data from the server-side view models available to the client-side code, such as which properties are required, and what validations are on each property. In the knockout mapping "create" callbacks, I wanted this information in order to automatically generate additional properties and computed observables in the view models. So, on the server side, I used some MVC framework classes and reflection to inspect the view models and generate some meta-data as JavaScript which gets embeded into the relevant views. On the client side, I have external JavaScript files which hook up the knockout mapping callbacks and generate view models according the meta-data provided in the page. My advice is to start out by writing the knockout view model customisations and other JavaScript by hand in each view, then as you refactor, move generic JavaScript functions out into external files. Each view should end up with only the minimal JavaScript that is specific to that view, at which point you can consider writing some C# to generate that JavaScript from your server-side view model annotations.
For the url issue add this in your _Layout.cshtml in a place where it is before the files that will use it:
<script>
window._appRootUrl = '#Url.Content("~/")';
</script>
Then you can use the window._appRootUrl to compose urls with string concatenation or with the help of a javascript library like URI.js.
As for the additional computed values, you may want to use a knockout computed observable. If that is not possible or you prefer to do it in .Net you should be able to create a property with a getter only, but this won't update when you update other properties on the client if it depends on them.
I'm developing an ASP.NET MVC2 web application.
I want to send an array of JSON objects from my view code using AJAX to the controller.
I have seen many examples of hot to do this using jquery.
However I would like to know how to do this using an Ajax request without using jquery?
I have read that updating to MVC3 may help, if this is the best solution can you point me in the right direction on how to update from MVC2 to MVC3?
Below is some sample code:
VIEW
var modRecords = store.getModifiedRecords();
Ext.Ajax.request({
url: AppRootPath +'EmployeeDetails/SetSAASUser',
params: {
users: modRecords
}
});
CONTROLLER
public JsonResult SetUser(IEnumerable<User> users)
{
GetData data = delegate
{
return Repo.SetUser(users);
};
JsonResultBase jsonResult = GetJsonResult(data);
JsonResult json = PortalJsonResult(jsonResult, JsonRequestBehavior.AllowGet);
return json;
}
To MVC3 or not to MVC3
No particular need to convert to MVC3 though because you can consume JSON in MVC2 as well. There are two actually many ways of doing it:
using JsonValueProviderFactory which Phil Haack described in his blog post that would give you exactly equivalent functionality as if you've used MVC3.
Pre-convert your client data so ExtJS will correctly send it to the server. This is somehow similar to what I've done with a jQuery plugin. A very similar thing could be done with ExtJS as well. These two steps are necessary to accomplish it:
First you'd need to analyse how your JSON object is converted on the wire (use Fiddler)
Write code that transforms your JSON into a form that will be correctly sent to the server. What form would that be? You can read about that in my previously mentioned blog post.
I don't know if you're aware of this but there's also something called Ext.Direct for ASP.NET MVC that may help you in this scenario. As it says it support simple, complex and array parameters which covers it actually.
The only advantage of using MVC3 is that JsonValueProviderFactory is enabled for you by default without any additional code.
I've used ExtJS few years ago when it was in version 2. No Ext.Direct and MVC back then yet. But we were very successful in pairing it to an Asp.net WebForms application with async calls to WCF using the same business+data layers as Asp.net WebForms application used.
I'm creating a search page, the page has a form that is being submitted using Ajax, after the search is performed I want to display a grid with the results.
My question is, should I create the grid when the page loads and then fill it with the data after the search is performed, or create the grid on the server when the search is performed and then just append the grid to the page.
I was thinking on creating a helper method to render the grid and invoking it from the controller after it gets the results, then returning the result of the helper method and appending it to the page, but this might be against MVC architecture (I'm defining UI on the controller).
What approach should I take?
Thanks
for the grid creation, you can have a look at MVCContrib grid helper
You could use jqGrid (http://www.trirand.com/blog/) or Flexigrid (http://www.flexigrid.info/) and load data with ajax and json. You submit search form with ajax, controller returns JsonResult, and then you load it into grid in callback. It is easy to implement and gives you additional functionalities (sorting and much, much more). Here you have some demos:
http://trirand.com/jqgrid/jqgrid.html