What files are you allowed to modify in SharePoint 2007?

Question

What files can we modify so that our solution is still supported by Microsoft?

Is it allowed to customize error pages? Can we modify the web.config files to use custom HTTPHandlers?

Answer 1

You can certainly edit the web.config file for your sites. The one thing that you should be aware of, however, is that when you start editing files manually on the file system, you will have to remember to manually make those changes across all servers in the farm (assuming a farm exists). In addition to this, when you edit files in the 12 hive, it's important to understand that you will be making a change to all SharePoint sites hosted on the server(s) for which the files were edited.

Personally, if I were going to create a custom error page, I would simply add a <customErrors> section to my web.config. I avoid editing any existing files in the 12 hive, but I have added files (though it's rare).

Answer 2

The customization of the error page is not very easy (or flexible). You can see an example here:

http://blogs.msdn.com/jingmeili/archive/2007/04/08/how-to-create-your-own-custom-404-error-page-and-handle-redirect-in-sharepoint-2007-moss.aspx

The web.config can be changed. I used my own HttpModules in addition to the original ones, but I haven't used custom HttpHandlers. IMO it should work if you don't change the original handler (i.e. if you add your handler for a specific type of file not handled by SP).

Answer 3

do not modify any pre-installed files in the 12 hive (Program Files\Common Files\Microsoft Shared\Web Server Extensions\12)... a service pack may update and overwrite any changes.

Anything in the Content Database (Masterpage, Stylesheets list in ~Catalogs) is available to modify (I would add, instead of update, in case a service pack changes anything) as it sits atop the file system, and is instantly available to any members of the web farm (newly added servers).

Any custom features, added to the 12 hive in the features folder, in a custom/non-microsoft folder (that is, inside the 12\feature folder, do not modify any preinstalled files, but feel free to add a folder for your feature and work within).

Custom features can be developed using the Visual Studio Extensions (VSeWSS), currently available for Visual Studio 2005/2008... benefit being that the output is a feature package (.WSP file) which is designed to be portable across SharePoint. Additionally, the .WSP files are just CAB files with a different extension, offering the ability to be explored by simply renaming them.

Answer 4

For site definitions, Microsoft has a good article about what is supported and unsupported. In short, the only change you can make to the out-of-the-box site definitions is changing the entry in the webtemp.xml file to hidden in order to prevent the site definition from appearing in the site template list. This is something many may be interested in doing.

You may also, of course, copy existing definitions and rename them in order to create new ones.

The complete list of supported and unsupported scenarios for working with custom site definitions can be found here:

http://support.microsoft.com/default.aspx?scid=kb;en-us;898631

Answer 5

Here is the closest I can find to a official response from Microsoft:

http://technet.microsoft.com/en-us/library/cc263010.aspx