I have a WebGrid declared as below:
WebGrid grid = new WebGrid(rowsPerPage: Model.RowsPerPage, ajaxUpdateContainerId: "WebGrid");
I noticed where ever there is a data-swhglnk="true" attribute in a <a></a> e.g. Columns for sorting, the asynchronous behavior occurs and my WebGrid is updated.
I want to tap into the same behavior without much change to update the WebGrid on my custom interaction like user passed a filter string from a textbox or changed the number of rows per page from a dropdown, etc.
I also noticed that a big number is sent to the server like http://localhost:6066/Grid?sort=ID&sortdir=ASC&__swhg=1388556493888 when there is data-swhglnk="true".
Can someone please shed some light on this matter?
Basically, I had to resort to doing my own custom ajax call and replacing the div with returned data. I could not tap into WebGrid's async behavior with my own callbacks.
Related
Is there a way to pre-populate a MultiSelectList with selected items?
Example:
I have a single View that has the following ListBoxFor that will cause the page to update what it's displaying by allowing filtering of Model.Companies.
#Html.ListBoxFor(m => m.SelectedCompanies, new MultiSelectList(Model.Companies, "IdString", "CompanyName")
What I'd like to have happen is after the update, the MultiSelectList will have the items that were selected before the page updated and refreshed. Does that mean I need to return SelectedCompanies with what was selected, or is there another way?
I am using the javascript library Chosen for usability of the ListBox on the client side, but I don't think that this affects what I'm trying to do.
Sometimes, JS libaries can interfere with your desired results. I can't speak for Chosen JS library, but inspect the markup and see how it renders. As long as it still has the listbox on the client (it must have some input element defined somewhere; my guess it hides it and updates the values as they are selected), then yes it should integrate fine.
However, when the controller posts back, you have to repopulate the Model.SelectedCompanies property with whatever values came back from the POST operation to the controller. The property should still have the selected companies if you return a View from the POST operation. If you are using a RedirectToAction instead, you'd have to store the selections in TempData.
I have a fairly simple site with a Search partial view and a Listing partial view. They're rolled up using multiple models into the Index view.
Everything is fine. Except when I click the grid column headers to sort or attempt to page to the next listing of data, the grid comes back empty. If I re-submit the same search criteria, then the grid repopulates with all applicable data sorted or paged properly.
I've tracked this behavior down to the fact that the WebGrid sets up it's paging and sorting mechanisms as a GET instead of a POST. So obviously all my model data is left off the submission.
Isn't there a way to get the WebGrid to POST so the data tags along? Seems quite counterproductive for the WebGrid as a class to not include the data one wants to page or sort.
Old question, but just to add a reference:
I preferred the solution suggested at this link
which solves the problem using JQuery:
var links = $('a[href*=page], a[href*=sort]'), form = $('form');
links.click(function () {
form.attr("action", this.href);
$(this).attr("href","javascript:");
form.submit();
});
This may not be the most elegant solution, but it works:
Add the model to your Session in the view:
Session.Add( "Model", Model );
Then, in the Index GET Action in your controller (or whatever the GET Action is), just check for the value and call the POST Action:
if ( Session[ "Model" ] != null )
this.Index( Session[ "Model" ] as MyModel );
Cleanup your Session accordingly.
Further to the JQuery answer above (which brought me success, thanks!) don't forget to undelegate the the webgrid's own magic methods that it adds behind the scenes. Otherwise you may end up with another ajax GET occurring at the same time as your POST.
Before binding to the 'page' and 'sort' links do this:-
$("#MyWebGridID").undelegate();
I need solution for my problem on urgent basis, I am new with mvc, knockout please provide me sample code for my problem. any help will be highly appreciated.
suppose I have an observable array in my viewmodel i.e
var viewmodel = {
vendorproviders : ko.observablearray([])
}
where vendorproviders list consist of multiple attributes like id, name, country, address etc
I want to populate that array in my grid where each row will have a select button, when that button is clicked it should post the id to my controller action either by submitting or by ajax call.
Furthor more that grid should be searchable like if there is a separate text box, based on the value of text box grid should display matching providers else display all providers.
when user search for particular provider grid should populate from observable array instead of making call at server again and again to pupulate the observable array.
I would suggest starting here.
http://learn.knockoutjs.com/#/?tutorial=intro
What you are talking about is all the basic functionality of the tools you referenced.
I'm making the transition from webforms to MVC (I know, 3 years late) and I "get it" for the most part, but there's a few things I'd like advice and clarification on:
First off, what happens if you want to dynamically add inputs to a view? for example, in an old webform for generating invoices I had a button with a server-side click event handler that added an extra 5 invoice item rows. The stateful nature of webforms meant the server handled the POST event "safely" without altering the rest of the page.
In MVC I can't think how I'd do this without using client-side scripting (not a showstopper, but I would like to support clients that don't have scripting enabled).
The second problem relates to the invoices example. If my Model has a List, how should I be generating inputs for it?
I know data binding is a possible solution, but I dint like surrendering control.
Finally, back to the "stateful pages" concept - say I've got a Dashboard page that has a calendar on it (I wrote my own calendar Control class, the control itself is stateless, but can use the webform viewstate to store paging information) - how could a user page through the calendar months? Obviously POST is inappropriate, so it would have to be with GET with a querystring parameter - how can I do this in MVC? (don't say AJAX).
Thanks!
In MVC you design your actions to accommodate your needs. For example, if you wanted to be able to add 5 rows to an invoice NOT using client-side scripting, you'd probably have your GET action for the invoice generation take a nullable int parameter for the number of rows. Store the current number of rows in the view model for the page and generate a link on the page to your GET action that has the parameter value set to 5 more than the current value. The user clicks the link and the GET view generates the page with the requested number of rows.
Controller
[HttpGet]
public ActionResult Invoice( int? rows )
{
rows = rows ?? 5; // probably you'd pull the default from a configuration
...
viewModel.CurrentRows = rows;
return View( viewModel );
}
View
#Html.ActionLink( "Add 5 Lines", "invoice", new { rows = Model.CurrentRows + 5 }, new { #class = "add-rows" } )
You would probably also add some script to the page that intercepts the click handler and does the same thing via the script that your action would do so that in the general case the user doesn't have to do a round trip to the server.
<script type="text/javascript">
$(function() {
$('.add-rows').click( function() {
...add additional inputs to the invoice...
return false; // abort the request
});
});
</script>
Likewise for your calendar. The general idea is you put enough information in your view model to generate all the actions that you want to perform from your view. Construct the links or forms (yes you can have multiple forms!) in your view to do the action. Use parameters to communicate to the controller/action what needs to be done. In the rare case where you need to retain state between actions, say when performing a wizard that takes multiple actions, you can store the information in the session or use TempData (which uses the session).
For things like a calendar you'd need the current date and the current view type (month/day/year). From that you can construct an action that takes you to the next month/day/year. For a paged list you need the current page, the current sort column and direction, the number of items per page, and the number of pages. Using this information you can construct your paging links that call back to actions expecting those parameters which simply do the right thing for the parameters with which they are called.
Lastly, don't fear AJAX, embrace it. It's not always appropriate (you can't upload files with it, for example), but your users will appreciate an AJAX-enabled interface.
In MVC you can store application state in various ways. In your controller you have direct access to the Session object and you can also store state to the database.
your view can contain basic control flow logic, so, if your model has a list you can iterate over it in the view and, for example, render an input control for each item in the list. you could also set a variable in a model to be the maximum number of rows on the viewpage and then render a row in a table for the number specified by the model.
paging is basically the same thing. you can create a partial view (user control in the webform world) that shows page numbers as links, where each link calls an action that fetches the data for that page of results.
i'm not sure what your beef is with ajax or javascript
I'm new to Ajax, but I think I know how to reasonably use MVC + model binding.
What I'm trying to do is to create an Add button (or Ajax.ActionLink) to add a new row in my grid for data entry. Example: Think of a typical Order entry system with Order (header) and Product (items). My OrderViewModel contains an "Order" object, and the Order object contains a collection List.
The way I plan to do this is that my View render the grid in a PartialView, and the PartialView is a simple for-loop to create the table tags from the List. I will use the default model binder (for collections).
Anyone have suggestions on how to do this?
I've already figured out how to do this using jQuery, but I want (i think I want) to try and use Ajax so that I can add my custom business logic (e.g. like setting defaults, translations, etc.)as opposed to do this client-side.
In other words, I want to do do something similar to what the Telerik grid does with its Ajax Editing with the Add/Remove link/buttons.
Tips and sample code would be greatly appreciated.
One of my challenges, and not sure if I'm going down the wrong way, is that I don't know how to pass back the model back to the Controller Action from the Ajax submit. When I look at Telerik's code, it looks like they store the persisted items in HttpContext.Session, and this is exactly the reason why I don't want to use their grid.
Thanks.
They might choose the session repository storage for demonstration purposes. If you transform the logic from their SessionProductRepository class for your model and implement identical Update/Insert/Delete methods for it, you'll probably get what you want.