Enable possibility to download json files in Sharepoint

Sometime you may need to enable possibility to download json file types in Sharepoint (e.g. we had a case when it was needed for integration purposes). By default if you will put this file e.g. into /_layouts folder and try to access json file in context of Sharepoint site:

http://example.com/_layouts/test/foo.json

you will get the following error:

The page must have a <%@ webservice class="MyNamespace.MyClass" ... %> directive.
 
Stack trace:    at System.Web.UI.SimpleWebHandlerParser.ParseReader
()
   at System.Web.UI.SimpleWebHandlerParser.Parse(ICollection
referencedAssemblies)
   at System.Web.Compilation.SimpleHandlerBuildProvider.get_CodeCompilerTy
pe()
   at System.Web.Compilation.BuildProvider.GetCompilerTypeFromBuildProvider
(BuildProvider buildProvider)
   at System.Web.Compilation.BuildProvidersCompiler.ProcessBuildProviders()
   at System.Web.Compilation.BuildProvidersCompiler.PerformBuild()
   at System.Web.Compilation.BuildManager.CompileWebFile(VirtualPath
virtualPath)
   at System.Web.Compilation.BuildManager.GetVPathBuildResultInternal
(VirtualPath virtualPath, Boolean noBuild, Boolean allowCrossApp, Boolean
allowBuildInPrecompile)
   at System.Web.Compilation.BuildManager.GetVPathBuildResultWithNoAssert
(HttpContext context, VirtualPath virtualPath, Boolean noBuild, Boolean
allowCrossApp, Boolean allowBuildInPrecompile)
   at System.Web.UI.WebServiceParser.GetCompiledType(String inputFile,
HttpContext context)
   at System.Web.Services.Protocols.WebServiceHandlerFactory.GetHandler
(HttpContext context, String verb, String url, String filePath)
   at System.Web.Script.Services.ScriptHandlerFactory.GetHandler
(HttpContext context, String requestType, String url, String pathTranslated)
   at System.Web.HttpApplication.MaterializeHandlerExecutionStep.System.Web
.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step,
Boolean& completedSynchronously)

In order to enable possibility to download json file from Sharepoint we need to do the following:

1. Create new application sub folder under your Sharepoint site in IIS manager. If you already have virtual folder you need to convert it to application also in IIS manager. Separate folder is needed in order to not affect whole Sharepoint, but only one exact url:

http://example.com/testappfolder

2. Add web.config to this folder and add mime type record for json extension under system.webServer > staticContent:

   1: <configuration>

   2:    <system.webServer>

   3:       <staticContent>

   4:          <mimeMap fileExtension=".json" mimeType="application/json" />

   5:       </staticContent>

   6:    </system.webServer>

   7: </configuration>

3. In IIS manager open handler mappings for your application sub folder and remove handler for *.json (that's why it is important to use separate application sub folder in IIS – in case of app this change will only affect this sub folder, not whole Sharepoint site. I.e. there won’t be side effects with this approach).

Now if we try to access http://example.com/testappfolder/foo.json its content will be successfully downloaded.