Sharing a master between MVC and WebForms - dealing with the <form>

Question

We have a large legacy application where we want to start using MVC for new functionality.

To do this we added custom routing, for instance:

routes.IgnoreRoute( "{*allaspx}", new { allaspx = @".*\.as[pmh]x(/.*)?" } );

And we want to share the master page between the old WebForms and the new MVC pages.

This seems simple enough - changed the master to inherit from ViewMasterPage and it can be used as the master for MVC pages too.

The problem is the HTML <form>.

The master page has a <form> tag at the top and 3 content panels inside it, which is how WebForms like it. The Page control overrides the master's form to point back at the page, and this appears to be a hardcoded behaviour.

All three content panels have WebForms controls, so the page level <form> tag needs to be outside them to cover all three. Something like this:

<form id="form1" runat="server">
    ...
    <asp:contentplaceholder id="content1" runat="server" />
    ...
    <asp:contentplaceholder id="content2" runat="server" />
    ... //etc
</form>

However, for MVC we want to have forms inside the views using the Html.BeginForm helper. HTML doesn't let you nest forms. MVC pattern needs the views to post back to different actions (for instance a "details" view might post back to an "edit" action).

Does anyone know a good way around this?

Answer 1

We share a master page between web forms and MVC which doesn't have the <form>. You can create an intermediate master page for web forms which in turn uses your root master page, but adds the <form>. The hierarchical structure of master pages is very useful for these constructs.