I am totally confused even after seeing the following explanation.
<div>
#Html.Partial("_FeaturedProduct")
</div>
Partial views can be rendered inside a Layout Page (or if using MVC 2/3 w/ASPX, the Master Page) as well as regular views.
There are some cases where you might like to step aside and write directly to the HTTP Response stream rather than having a partial view render the results (partials/views use MvcHtmlString/StringWriter). To do so, use the Html.RenderPartial helper.
<div>
#Html.RenderPartial("_FeaturedProduct")
</div>
Can someone tell me what it means? What cases where I might like to write direct to the HTTP Response etc. What if my partial view contains just one line like this:
<h1>Hello</h1>
Which should I use and why? What would happen if I used the other?
The following confused me even more: "Use Html.RenderPartial for streaming images or other elements that are media-centric or where faster download times are highly important."
See the response below.
The only difference is that Partial returns an MvcHtmlString, and must
be called inside <%= %>, whereas RenderPartial returnsvoid and renders
directly to the view.
If you look at the source code, you'll see that they both call the
same internal method, passing a StringWriter for it to render to.
You would call Partial if you want to view, save, or manipulate the
generated HTML instead of writing it to the page.
What is the difference (if any) between Html.Partial(view, model) and Html.RenderPartial(view,model) in MVC2?
Related
I have some html that is used a lot in the site i'm building. So I created a App_Code\Helpers.cshtml file and placed the helperfunction in that file.
Now, I want to render a partial-view (a MVC view for a form). But I can't use #Html.Partial("MyFormPartial", new formModel())
I can't find any other ways of rendering a partial view from within a helper class. Anybody got an idea on how to solve this?
Is a seperate helpers.cshtml even the best way for this kind of repeating html-code? I think it gives me a bit more freedom in the parameters I'm providing, instead of the macro's. But it sucks I can't use #Umbraco (without creating your own helper) or #Html :(
Just pass #Html to the helper function if you don't want to create it inside the helper function.
Nevertheless, isn't it a better idea to use a child action and render part of code you'd like to been shared?
I am new to MVC , and in the application i downloaded and trying to debug i see this mark up
#Html.Widget("body_start_html_tag_after")
#Html.Partial("_Notifications")
#Html.Action("AdminHeaderLinks", "Common")
What does this mean?, #Html.Partial where can I find where the value "body_start_html_tag_after") is defined ?
And this one:
<div class="master-wrapper-main">
#RenderBody()
</div>
Where can i find what #RenderBody does?, this is in a .cshtml file.
I would suggest that you look at a reference like http://www.asp.net/mvc to gain a greater understanding of ASP.Net MVC. Having said that the #HTML.Widget, etc is server side code that gets called during the HTML generation process.
I have heard of nopCommerce but I am unfamiliar with the structure, but #Html is usually used for server side helper methods.
#Html.Partial("_Notifications") is used to add the _Notifications Partial view to the page being rendered.
#Html.Action method will render a html A tag with the href link to the controller and action to be performed.
#Html.Widget I am unfamiliar with but one could assume that it is a helper method.
#RenderBody is used on a master page (usually the shared/_Layout.cshtml) as a server side marker to render the view that comes from the associated controller.
I have my user control in a class library and I have a public method in it which returns the user control as html string. I want to display this HTML in my MVC view. I am using the following code in my view:
<div>
<% MyControlsNamespace.MyControl mvc = new MyControl();
mvc.LoadMyControl(); %>
</div>
LoadMyControl() returns html as string. I can't see any thing in my view when I open it in a browser. I am new to MVC and I knew I am missing some thing here. Any guess??? I am using MVC1
Use <% Html.RenderPartial("Path/To.ascx") %> or <%= Html.Partial("Path/To.ascx") %>.
Use RenderPartial when you're fine with the user-control rendering directly to the response stream, or use Partial if you want to intercept the output as an MvcHtmlString. RenderPartial is faster and generally preferred, only use Partial if you know you need the MvcHtmlString.
More information is available here: Html.Partial vs Html.RenderPartial & Html.Action vs Html.RenderAction
I have a page where I want to do an AJAX call and possibly render a partial every 30 seconds or so. Now, I know how to do this with jquery AJAX, doing an AJAX call and passing in the path, but it doesn't seem like the Rails way.
I say this because the result is that the main view does not show you the entire structure of the page. When you render a partial, you at least see the partial's positioning inside the document, if you render a partial via AJAX, you have to read the javascript code to know that it's there.
Is there a more unobtrusive (for lack of a better word) way to do this?
When I need to do something like this, and want the partial block to be positioned, I include a container div that I then render the AJAX call into. That was I can position the partial prior to it actually being rendered.
I created an html helper
Html.BreadCrumb(IDictionary<string, string> crumbs)
Where the first string is the label and the second string is the URL.
The helper creates the html required (an unordered list, some classes for first element, current element, last element, dead element and separators etc)
All working nice, but I do this by creating a stringbuilder, pumping all the html in it and returning the stringbuilder's content as a string.
I figure in this example it doesn't matter all that much, but what if an Html helper is churning out a big load of html? Isn't there a way to push it to Response.Write instead of a stringbuilder?
Or any other issues/improvements you have?
BTW we have a naming pattern in ASP.NET MVC for the various rendering techniques.
Helpers that return a string of what they are should be named what they are. For example, Url.Action() and Html.TextBox() return those exact items. Thus, these helpers should be used with the <%= %> syntax.
Helpers that render directly to the output stream should start with Render. For example, Html.RenderPartial(). These are used with the <% %> syntax.
Helpers that use the IDisposable pattern should be named with Begin/End. For example, Html.BeginForm() and Html.EndForm(). These should also be used with the <% %> syntax.
Thanks,
Eilon
It certainly is possible to use Response.Write instead of returning a string; see the source for System.Web.Mvc.Ajax.Form (in AjaxExtensions.cs) in the MVC source for an example.
You then call the helper with <% instead of <%=.
Will it be any faster? I doubt it, but it's easy to test.
I don't think you will have any performance problems as long as the size of the HTML pages you produce is reasonable. And when you really start to create pages of megabytes in size, then you should ask yourself, why are you creating such huge HTML files?