modify web.config programatically to add a workflow authorized type

Question

I need to add a line in the web.config under authorizedtypes, I want to do it with a wsp solution so that sharepoint takes care of syncrhonizing it with other front end servers.

I just want to put this line:

<authorizedType Assembly="MyCompany.CustomActivities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=207090b9b3f674c8" Namespace="MyCompany.CustomActivities" TypeName="*" Authorized="True" />

Answer 1

I've implemented this method in the past, so I just share my code with you:
add:

private void AddAuthorizedType(SPWebApplication webApplication, string assembly, string namespace_)
{
    SPSecurity.RunWithElevatedPrivileges(delegate
     { 
         var modification = new SPWebConfigModification();
         modification.Path = "configuration/System.Workflow.ComponentModel.WorkflowCompiler/authorizedTypes";
         modification.Name = string.Format("authorizedType[@Assembly='{0}'][@Namespace='{1}'][@TypeName='*'][@Authorized='True']", assembly, namespace_);
         modification.Sequence = 0;
         modification.Type = SPWebConfigModification.SPWebConfigModificationType.EnsureChildNode;
         modification.Value = string.Format("<authorizedType Assembly='{0}' Namespace='{1}' TypeName='*' Authorized='True'/>", assembly, namespace_);
         webApplication.WebConfigModifications.Add(modification);
         webApplication.Update();
         webApplication.Farm.Services.GetValue<SPWebService>().ApplyWebConfigModifications();
     });
}

and remove:

private void RemoveAuthorizedType(SPWebApplication webApplication, string assembly, string namespace_)
{
    SPSecurity.RunWithElevatedPrivileges(delegate
    {
        SPWebConfigModification configMod = null;
        var modsCollection = webApplication.WebConfigModifications;

        // Find the most recent modification of a specified owner
        foreach (SPWebConfigModification modification in modsCollection)
        {
            if (modification.Name.Equals(string.Format("authorizedType[@Assembly='{0}'][@Namespace='{1}'][@TypeName='*'][@Authorized='True']", assembly, namespace_), StringComparison.OrdinalIgnoreCase))
            {
                configMod = modification;
            }
        }

        if (configMod != null)
        {
            // Remove it and save the change to the configuration database  
            modsCollection.Remove(configMod);
            webApplication.Update();

            // Reapply all the configuration modifications
            webApplication.Farm.Services.GetValue<SPWebService>().ApplyWebConfigModifications();
        }
    });
}

NOTE: make sure this feature has web application scope, because if not, your code may not work, due to RemoteAdministratorAccessDenied settings.

Answer 2

We've found it's much easier to just add a webconfig.something.xml file to the Config folder. So for your one entry you can create an xml file with these contents:

<?xml version="1.0" encoding="utf-8" ?>
<actions>
  <remove path="configuration/System.Workflow.ComponentModel.WorkflowCompiler/authorizedTypes/authorizedType[@Namespace=&quot;MyCompany.CustomActivities&quot;]" />
  <add path="configuration/System.Workflow.ComponentModel.WorkflowCompiler/authorizedTypes" >
    <authorizedType Assembly="MyCompany.CustomActivities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=207090b9b3f674c8" Namespace="MyCompany.CustomActivities" TypeName="*" Authorized="True" />
  </add>
</actions>

Name this file in the form webconfig.something.xml replacing something with your Solution Name or something else to distinguish it.

This xml file can be part of your solution set to copy itself to [HivePath]\CONFIG folder. If you are creating your solution in Visual Studio just add a new Root File (SharePoint file-system template file). Add a CONFIG folder under the RootFiles folder and place your new xml file there.

Then whenever web.config rebuilds itself it will do so with your actions specified above. The first time you deploy the solution you will need to add an extra step of calling:

stsadm -o copyappbincontent

This is true for both SharePoint 2007 and SharePoint 2010.