Ok, i can use jeditable to edit-in-place some content on a page and the content will be saved to a database. But whats the best way to re get that text-content from db to show into a place holder?
p id="paraNo34" class="editable"
-->What i will write here so that it will get content from a
db's table: [Content], where id=="paraNo34".
/p
The problem is if i will use some hard coded text like
p id="paraNo34" class="editable"
-->Some text here
/p
I will able to edit-in-place using jeditable but when i will refresh page it will show the same "Some text here" as its not getting data from db.
Your pseudocode implies that you want the view to be responsible for fetching the required data, which is an anti-pattern in MVC. You need to retrieve the text in your controllers action and pass it to the view, either using ViewData or a custom view model, e.g.:
public ActionResult Index(string id)
{
// call some method to fetch data from db
ViewData["ID"] = id;
ViewData["Content"] = content;
return View();
}
And the view looks something like:
<p id='<%= ViewData["ID"] %>' class="editable">
<%= Html.Encode(ViewData["Content"]) %>
</p>
A better approach would be to create a strong-typed view model (Stephen Walther has a blog post about view models here), but the above example should illustrate how data can be passed from the controller to the view.
Related
can a Partial Views on mvc create view that is using a dropdown list that sends value from the dropdown list to a function that creates a list based on the dropdown list value selection, That is then stored in a view bag for the partial view.. Can this be done in mvc and can it be done on create view of a mvc form?
I can see how something this would work in the edit view because the dropdown list value has already been selected when the page loads.
But on a new Create view record nothing is selected so the list function has a null value
Are partial views only for forms that have data pre-populated in them?
Update:
I have a create view that was created by the visual studio wizard. It has both a post and get under the create. When the user in the create view. I have a dropdown list on the page form with other fields but on load of that new create page it is empty. Unfortunately for me I wanted my partial view to to get populated with a list of data that gets sent to a view bag after the user make a selection from the drop down list.
I think what I am asking to do can only be done with webforms as mvc can handle dynamic data all that well it seems. And since when the page loads the dropdown has no value.. the list can't built so there is a null value error as well as and empty list if I hard code a value in the drop down list.
Here is my Code in these different attempt threads with different veration of my code documenting my many attempts. As I have comcluded it is not possible sadly.
Can a Drop Down List Trigger A Partial View To Update on A Create View Form In mvc?
Null view bag and partial view
Populating Partial Views using mvc
Updating a Partial View in MVC 5
So with help from Matt Bodily You can Populate a Partial View in the create view triggered by a changed value in a drop down list using a view bag and something called Ajax. Here is how I made my code work.
First the partial view code sample you need to check for null data
_WidgetListPartial
#if (#ViewBag.AList != null)
{
<table cellpadding="1" border="1">
<tr>
<th>
Widget Name
</th>
</tr>
#foreach (MvcProgramX.Models.LIST_FULL item in #ViewBag.AList)
{
<tr>
<td>
#item.WidgetName
</td>
</tr>
}
</table>
}
Populating your View Bag in your controller with a function
private List<DB_LIST_FULL> Get_List(int? VID)
{
return db.DB_LIST_FULL.Where(i => i.A_ID == VID).ToList();
}
In your Create controller add a structure like this using the [HttpGet] element
this will send you data and your partial view to the screen placeholder you have on your create screen The VID will be the ID from your Drop down list this function also sends back the Partial View back to the create form screen
[HttpGet]
public ActionResult UpdatePartialViewList(int? VID)
{
ViewBag.AList = Get_List(VID);
return PartialView("_WidgetListPartial",ViewBag.AList);
}
I am not 100% if this is needed but I added to the the following to the ActionResult Create the form Id and the FormCollection so that I could read the value from the drop down. Again the Ajax stuff may be taking care if it but just in case and the application seems to be working with it.
This is in the [HttpPost]
public ActionResult Create(int RES_VID, FormCollection Collection, [Bind(Include = "... other form fields
This is in the [HttpGet] again this too may not be needed. This is reading a value from the form
UpdatePartialViewList(int.Parse(Collection["RES_VID"]));
On Your Create View Screen where you want your partial view to display
<div class="col-sm-6">
<div class="form-horizontal" style="display:none" id="PV_WidgetList">
#{ Html.RenderAction("UpdatePartialViewList");}
</div>
</div>
And finally the Ajax code behind that reads the click from the dropdown list. get the value of the selected item and passed the values back to all of the controller code behind to build the list and send it to update the partial view and if there is data there it pass the partial view with the update list to the create form.
$(document).ready(function () {
$('#RES_VID').change(function ()
{
debugger;
$.ajax(
{
url: '#Url.Action("UpdatePartialViewList")',
type: 'GET',
data: { VID: $('#RES_VID').val() },
success: function (partialView)
{
$('#PV_WidgetList').html(partialView);
$('#PV_WidgetList').show();
}
});
This many not be the best way to do it but this a a complete an tested answer as it work and it is every step of the process in hopes that no one else has to go through the multi-day horror show I had to go through to get something that worked as initially based on the errors I thought this could not be done in mvc and I would have to continue the app in webforms instead. Thanks again to everyone that helped me formulate this solution!
No, partial views do not necessarily have to be strongly typed, if that's your question. You can have a partial view with just html markup.
I have this scenarion.
There are Boards. And Threads. Therads can be created only on boards, and for that they need to be provided with board ID, Name or something like that, to let SQL know where it should add thread.
By now I've been using hidden fields to pass data between views, but more I used them tehre was more trash in code like ViewBags, unnesseary attributes in methods etc.
Are there cleaner ways to do it ?
Pass the model back to the view.
so if you have a model called Data with a field called Name then;
Data fvm = new Data{ Name = "my name"};
return View(fvm)
then inherit the view from the model and use;
<%= Model.Name %> to get data.
Then as you move from view to view you pass the form back to the view with either ajax, jQuery submit plugin or a submit button which should also be the model.
then in your controller;
public actionresult myciew(Data model)
{
//do something with the model
}
I am having trouble following good object-oriented design in ASP.NET MVC2 and I think the problem is a poor understanding of how ViewModels and Views should interact when the user will be posting information.
I have implemented a forum that allows users to create replies to a thread using a Reply action. My ReplyViewModel contains an int for the threadId and a string for the reply's content. The Reply action creates a ReplyViewModel with the ThreadId so we'll know to which thread the user is replying. The Reply View is strongly typed to the ReplyViewModel and has a form allowing the user to edit the model's content. The user can then post to the Reply action with the threadId as a parameter.
It works, but I don't think I'm doing this the correct way. Each post involves two ReplyViewModels: one with the threadId but null content, and the other with content but a null ThreadId. The Reply View is creating a new ReplyViewModel, and I think it should just be editing the ReplyViewModel that was passed to the view--but I don't know how.
Here's a stripped-down version of the view:
<%# Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<mvcForum.ViewModels.ReplyViewModel>" %>
<%: Html.TextAreaFor(model=> model.content, new{TextMode="multiline", id="postbox"})%>
<input type="submit" value="Reply" />
In case that's not enough to answer my question, here's the entire view: http://pastebin.com/BFGL4p67
The ViewModel is literally just a string (content) and an int (threadId).
The controller:
[Authorize]
public ActionResult Reply(int id)
{
ReplyViewModel reply = new ReplyViewModel
{
ThreadId = id
};
return View(reply);
}
[HttpPost]
public ActionResult Reply(int id, ReplyViewModel model)
{
/**TODO: Catch when no user*/
var newPost = new ForumPost
{
UserId = (Guid)Membership.GetUser(User.Identity.Name).ProviderUserKey,
ThreadId = id,
postContent = model.content
};
db.AddToForumPosts(newPost);
db.SaveChanges();
return RedirectToAction("Index");
}
So my question is "What's the best way to do what I'm trying to do? Can I use a single instance of the ReplyViewModel to pass from the controller, to the view, and back to the controller?"
I think what you're doing is fine.
You're thinking about a problem that you haven't come across yet, which is when the data to populate the form differs greatly from the data that will be posted. Here the 'Get' view model is a subset of the 'Post' view model, so using one view model is fine, but if the data for the 'Get' and the data for the 'Post' differed greatly, you could use two different view models such as:
public class GetReplyFromViewModel //...
public class PostReplyFromViewModel //...
But I would suggest against this unless both view models were very different and sufficently complex to require their own view models.
One important thing to remeber: just because the view is strongly typed to type 'A' doesn't mean the type of the parameter in the post method can't be type 'B'.
The type of the View will simply determine the compilation / intellisense in the view along with the type checking of the view whenever one is created.
The type of the post method parameter will simply use the MVC Model Binding to convert the posted HTTP form to the type you specify.
In other words the type of your view could simply be
<%# Page Title="" ... Inherits="System.Web.Mvc.ViewPage<int>" %>
Where the whole Model variable is simply the ThreadId if you like and the post method could still take the same parameter if your html fields were named properly.
but again, in this particular case I think the current implementation is just fine.
I'm new to MVC, so please bear with me. :-)
I've got a strongly typed "Story" View. This View (story) can have Comments.
I've created two Views (not partials) for my Comments controller "ListStoryComments" and "CreateStoryComment", which do what their names imply. These Views are included in the Story View using RenderAction, e.g.:
<!-- List comments -->
<h2>All Comments</h2>
<% Html.RenderAction("ListStoryComments", "Comments", new { id = Model.Story.Id }); %>
<!-- Create new comment -->
<% Html.RenderAction("CreateStoryComment", "Comments", new { id = Model.Story.Id }); %>
(I pass in the Story id in order to list related comments).
All works as I hoped, except, when I post a new comment using the form, it returns the current (parent) View, but the Comments form field is still showing the last content I typed in and the ListStoryComments View isn’t updated to show the new story.
Basically, the page is being loaded from cache, as if I had pressed the browser’s back button. If I press f5 it will try to repost the form. If I reload the page manually (reenter the URL in the browser's address bar), and then press f5, I will see my new content and the empty form field, which is my desired result.
For completeness, my CreateStoryComment action looks like this:
[HttpPost]
public ActionResult CreateStoryComment([Bind(Exclude = "Id, Timestamp, ByUserId, ForUserId")]Comment commentToCreate)
{
try
{
commentToCreate.ByUserId = userGuid;
commentToCreate.ForUserId = userGuid;
commentToCreate.StoryId = 2; // hard-coded for testing
_repository.CreateComment(commentToCreate);
return View();
}
catch
{
return View();
}
}
The answer is to use return RedirectToAction(). Using this enforces the PRG pattern and achieves my goal.
My earlier comment to my original post did cause an error, that I guess I'm still confused about, but this works:
return RedirectToAction("Details", "Steps", new { id = "2" });
I, and this is a personal opinion, think you've tackled this the wrong way.
Personally I would;
Create a view called ListStories.
Create a partial view that lists the
stories.
Create a partial view to create a
story.
When you want to add a story, simply
show the add story html.
Then when the user presses a button
you do a jQuery postback, add the
new story and return a PartialView
of either the new story or all the
stories.
If you return a partial view of all
stories then replace the bounding
div that contains all the stories
with the new data.
If you return only a single story
then append it to the end of the div
containing the stories.
I know this means a lot of re-work and it sounds complex and like a lot of work but doing it like this means greater flexibility later on because you can re-use the partial views or you can make a change once and all views using that partial view are now updated.
also, using jQuery means that the adding of stories looks seemless w/out any obvious post back which is nice.
Since the problem seems to be caching, you can simply disable/limit caching.
Add the following attribute to your actions:
[OutputCache(Duration = 0, VaryByParam = "none")]
This will tell the browser to cache the page, but for 0 seconds. When the post reloads the page, you should see the desired results.
The answer is to make sure your form action is properly set. If you have used renderaction and not set the form controller and action manually then the action will be the current URL.
Try:
<% using (Html.BeginForm("ActionName", "ControllerName")) {%>
Instead of:
<% using (Html.BeginForm()) {%>
A function returns only one view.
what if I want to return multiple views in a function?
For example, I have this code:
Function Index() As ActionResult
Dim _news As DataTable = News.newsSelect()
Dim _announcement As DataTable = Announcement.SelectAnnouncement()
Return View()
End Function
I want to return _news and _announcement to be used in the aspx page. How would I do this?
Are you trying to show both sets at the same time? News and Announcements?
If so then why not implement either a PartialView or two PartialViews?
Then in your main view you can render them and pass the collection to the PartialViews?
There are heaps of samples on this and the one I recommend is in NerdDinner if you haven't already seen it.
I hope this helps. If you want sample code then let me know.
One simple way is just to have those two datasets sent in a ViewData element, which you can access in a field.
example:
ViewData["Elements"] = new SelectList(aElements, "Guid", "Name");
is consumed as:
<%= Html.DropDownList("Elements","Pick an element")%>
Also, I think that if you read between the lines of this blog post here you will find an elegant way of achieving what you want ;) but its a bit more involved..(only because you mentioned Views instead of just variables..
Quote:
We need to create our own implementation of IViewFactory. This
is responsible for locating and
creating an instance of an IView
(which both ViewPage and
ViewUserControl implement).
To “inject” (all you DI fans excuse me borrowing the term without
using a DI framework) our new View
Factory into every Controller we are
going to create our own
IControllerFactory implementation.
We need to configure the framework to use our new Controller
Factory.
Finally we can create two Views – an AJAX version and a pure
HTML version.
Building on that should be all you need
Good luck!
Ric
Assuming what you are trying to do is use both of those DataTables to populate some View, then my recommendation would be to create a wrapper object and then a strongly typed view based on this object.
The wrapper object would contain properties for all of the data elements that you need in order to render your view properly. In your case, it is 2 DataTable objects. I do not really know VB, so all my examples will be in C#. Here is an example of the data wrapper class...
public class IndexViewData
{
public DataTable News { get; set; }
public DataTable Announcement { get; set; }
}
You then might update the Index action in your controller as follows:
public ActionResult Index()
{
var viewData = new IndexViewData();
viewData.News = News.newsSelect();
viewData.Announcement = Announcement.SelectAnouncement();
return View(viewData);
}
Finally, you would need to create/update your view to be strongly typed. This is done by having your page inherit from the generic System.Web.Mvc.ViewPage<T> class. Just substitute the view data wrapper created earlier for T. To do this, you would set the inherits attribute of the <%# Page %> element. In your case, if we assume your root namespace is called "Foo", you might have the following page declaration in your Index.aspx view (added extra line breaks for readability):
<%# Page Title=""
Language="C#"
MasterPageFile="~/Views/Shared/Site.Master"
Inherits="System.Web.Mvc.ViewPage<Foo.Models.MyModelType.IndexViewData>"
%>
Once you have a strongly typed view for your view data wrapper, you can access the wrapper object in your view using the Model property. Here is an example of something you could do in your Index.aspx view
<%-- Output some random data (bad example, for demonstration only) --%>
<%= Model.News[0]["title"] %><br/>
<%= Model.Anouncement[0]["body"] %>
In reality you're probably going to do something like iterate over each row of the data table. Regardless, once you create the strongly typed view, your model object, which was passed to the view in the Index method of the controller, is available in the Model property within the view.
You can find detailed tutorials at the ASP.NET MVC site