In SharePoint 2007, Application Pages would inherit from Application Master deployed to Layouts folder. The Site Pages would inherit from a different Site Master deployed to SharePoint Content database. Since there was no way for application pages to inherit from the same master as that of the site pages, the look and feel of the two kinds of pages in a SharePoint application would be different, by default. This problem is overcome in SharePoint 14 with the introduction of Dynamic Master Page feature.
Application Pages that wants to inherit from site master will have to specify DynamicMasterPageFile attribute instead of the MasterPageFile attribute in the Page directive as
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="ApplicationPage1.aspx.cs" Inherits="SharePointProject15.Layouts.SharePointProject15.ApplicationPage1" DynamicMasterPageFile="~masterurl/default.master" %>
DynamicMasterPageFile attribute can only take two tokens as values; ~masterurl/default.master or ~masterurl/custom.master. These tokens will be resoved by SharePoint at runtime to point to the site's default master and the site's custom master respectively.
Deploying a custom content master page and using it in an application page involves three steps:
- Create and deploy a custom content master.
- Create and deploy a site definition that uses the content master created in step #1 and create a site based on it. [Creating a site definition is just for illustration and is not necessary if you are modifying an existing Site to point to a new content master.]
- Create an application page to be deployed to the site created in step #2
1. Create and deploy a custom content master.
1.1 Create a C# empty SharePoint project with all default selections and add a module element with name "MasterPage" to it.
1.2 Delete the sample.txt by right clicking on it in the solution explorer and selecting delete
1.3 In Solution Explorer, Right click the "MasterPage" module folder and add a file with name MyCustomContent.master (For example you can add a text file and change the extension from .txt to .master) and add the content to this file. Or you can start with SharePoint's existing content master and modify as needed. For simplicity let us choose an existing content master and proceed with it. To do this, go to master page gallery in SharePoint. Click on the dropdown of the master page you wish to save for example. Minimal.Master and select "Send To" and then "Download a Copy" and save the file.
Right click the "MasterPage" module folder and select "Add Existing" to add the saved master page. Be sure to change the name of the master page (say for example MyCustomContent.master) to avoid overwriting the SharePoint created master page. Double click on the master page to open it in the default editor and make the necessary modifications to the master page. In order to demonstrate the active master page is the new custom master in a simple way, let us change the ContentPlaceHolder with Id "PlaceHolderMain" to "PlaceHolderMyCustomMain".
1.4 Modify the element file associated with the module as follows:
<?xml version="1.0" encoding="utf-8"?>
<Module Name="MasterPage" Url="_catalogs/masterpage">
<File Path="MasterPage\MyCustomContent.master" Url="MyCustomContent.master" />
1.5 Right click the project in the solution explorer and select Deploy.
1.6 Verify that the master page got deployed to the master page gallery.
2. Create and deploy a site definition that uses the content master created in step #1 and create a site based on it.
2.1 Create a C# SharePoint Site Definition project called "MyCustomSiteDefinition".
In the onet.xml that gets created as part of the Site Definition project modify the configuration element so that the MasterUrl and CustomMasterUrl points to the newly deployed custom content master, as follows
<Configuration ID="0" Name="MyCustomSiteDefinition" MasterUrl="/_catalogs/masterpage/MyCustomContent.master" CustomMasterUrl="/_catalogs/masterpage/MyCustomContent.master">
Since we have changed the PlaceHolderMain to PlaceHolderMyCustomMain, we will also have to change it in the default.aspx. If we miss this step, SharePoint will throw error when we create a site based on this site definition.
2.2 Open the default.aspx file in the Site Definition project and change the ContentPlaceHolderId attribute in the default.aspx file to "PlaceHolderMyCustomMain" as shown below.
2.3 Right click the Site Definition project in the solution explorer and select Deploy.
2.4 In SharePoint, Click Site Actions | New Site. Select SharePoint Customizations link on the left navigation, enter the title and Url name for your site (example MyCustomSite)
2.5 Click on Create to create the site.
3. Create an application page to be deployed to the site created in step #2.
3.1 Create a C# Empty SharePoint project with local site used for debugging pointing to the site created in step #2 which is http://<machineName>/MyCustomSite.
Choose the option to Deploy as a farm solution. This is required since application pages can only be deployed to layouts folder and not to content database.
3.2 Click Finish and add an Application Page to the project. Right click on the Application Page and select "Set as Startup Item" to set it as startup item.
By default, it shows a warning since the active master page does not have "PlaceHolderMain" defined. If you invoke the IntelliSense, the new placeholder can be seen.
This application page inherits the newly deployed content master and the IntelliSense reflects the same. Press F5 to deploy it and view it in SharePoint. You can see that the look and feel of this page is inherited from the new custom content master.