Propagate Site Content Types to List Content Types

[Aka: Make Content Type Inheritance Work for XML Based Content types]

[Note:Updated Nov 6]

If you are working with XML based content types, you’ll sooner or later fall into a trap well hidden by Microsoft. Simply put Content Type inheritance don’t work for XML based content types. SharePoint does not check what fields you’ve added/deleted/changed since you last deployed your content type feature, so you don’t have the “luxury” (it bloody well should work!) of choosing whether or not to propagate changes down to inherited content types as in the web interface or object model.

I found MS mention it briefly here.

The Role of List Content Types

I’ll take a small detour here to explain the concept of list content types. Whenever you assign a content type to a list (e.g. the pages document library for publishing webs) a new list content type is created which inherits from the site content type that you are assigning to the list and with the same name.

Actually the inheritance copies the site content type definition to the list content type in its entirety and assigns an “inherited” content type id to the new list content type.

If you later modify the site content type, through the web or object model, you have the option of propagating those changes to inherited content types, which in particular includes all the list content types on the site.

Don’t Disconnect the Content Type

Another small detour before I’ll present what to do about this mess. It should be stressed that any modification of the site content type through the web or object model, will disconnect the site content type from the underlying xml metadata file. If it happens you my reestablish the link as described here. This is very bad news. It not only means that you should be careful about what you do to your content types, but it also means that there is no simple way to propagate the changes code wise – we can’t just update the site content type (re-add fields) and have the changes propagate through the object model.

The Code to Propagate

Finally I’m ready to present the code I used to propagate changes to my content types.

The procedure is:

1. Locate the site content type in question (run it multiple times if needed)
2. Start at the root web site
   1. Go through all lists on the web
   2. If the list is associated with the site content type (actually the inherited list content type)
      1. Compare every field on the site content type with the list content type
      2. Add, remove or change the field in question on the list content type
   3. Go recursively through every subweb and continue from step a

I created the following code as a new extension to stsadm, called like this:

stsadm -o cbPropagateContentType -url <site collection url> -contenttype <contenttype name> [-verbose] [-removefields] [-updatefields]

For instance:

stsadm -o cbPropagateContentType -url http://localhost -contenttype “My Article Page” –verbose

The “removefields” switch specifies whether or not fields found in the list content type that are not in the site content type should be removed or not. Default is not. New fields in the site content type will always be added to the list content types.

Note: I’ve not tried to create an “update” field. I’ve not had a use for that yet and it will also require considerably more testing to ensure that it works correctly. You really don’t want to break your list content types in case of errors…

Updated (Nov 6): An update option has now been added you should consider that option as beta.

Note 2: If the job stops prematurely no harm is done. Restart it and it will continue from where it stopped – it will examine and skip the webs/lists that it already has processed.

Finally something tangible:

Save the following as “stsadmcommands.CBPropagateContentType.xml” and save it into “\Config” in the root of the SharePoint install folder (remember to update the assembly reference to whatever you compile the code into):

<?xml version="1.0" encoding="utf-8" ?>
<commands>
  <command name="cbpropagatecontenttype"
          class="Carlsberg.SharePoint.Administration.STSAdm.CBPropagateContentType,
          Carlsberg.SharePoint.Administration, Version=1.0.0.0, Culture=neutral,
          PublicKeyToken=55c69d084ac6678f"/>
</commands>

And finally the code you need to compile to an assembly that the xml file should specify:

Updated (Nov 6): Code has been updated a bit. Some mistakes with display name/internal name have been fixed and the update option has been added. I’m not yet satisfied with the testing of the update method so consider it to be beta.

using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Text;
using Microsoft.SharePoint;
using Microsoft.SharePoint.StsAdmin;

namespace Carlsberg.SharePoint.Administration.STSAdm
{
    ///
    /// A custom STSAdm command for propagating site content types to lists
    /// content types.
    ///
    /// The code is provided as is, I don't take any responsibilty for
    /// any errors or data loss you might encounter.
    ///
    /// Use freely with two conditions:
    /// 1. Keep my name in there
    /// 2. Report any bugs back to http://soerennielsen.wordpress.com
    ///
    /// Enjoy
    /// Søren L. Nielsen
    ///
    ///
    class CBPropagateContentType : ISPStsadmCommand
    {
        #region Input parameters
        private string providedUrl;
        private string contentTypeName;
        private bool removeFields = false;
        private bool verbose = false;
        private bool updateFields = false;

        private bool UpdateFields
        {
            get { return updateFields; }
            set { updateFields = value; }
        }

        private bool Verbose {
            get { return verbose; }
            set { verbose = value; }
        }

        private bool RemoveFields {
            get { return removeFields; }
            set { removeFields = value; }
        }

        private string ContentTypeName {
            get { return contentTypeName; }
            set { contentTypeName = value; }
        }

        private string ProvidedUrl {
            get { return providedUrl; }
            set { providedUrl = value; }
        }
        #endregion

        ///
        /// Runs the specified command. Called by STSADM.
        ///
        /// The command.
        /// The key values.
        /// The output.
        ///
        public int Run(string command, StringDictionary keyValues,
                       out string output) {
            //Parse input
            // make sure all settings are valid
            if (!GetSettings(keyValues)) {
                Console.Out.WriteLine(GetHelpMessage(string.Empty));
                output = "Required parameters not supplied or invalid.";
            }

            SPSite siteCollection = null;
            SPWeb rootWeb = null;

            try {
                // get the site collection specified
                siteCollection = new SPSite(ProvidedUrl);
                rootWeb = siteCollection.RootWeb;

                //Get the source site content type
                SPContentType sourceCT =
                             rootWeb.AvailableContentTypes[ContentTypeName];
                if (sourceCT == null) {
                    throw new ArgumentException("Unable to find "
                        + "contenttype named \"" + ContentTypeName + "\"");
                }

                // process the root website
                ProcessWeb(rootWeb, sourceCT);

                output = "Operation successfully completed.";
                Log( output, false );
                return 0;
            }
            catch (Exception ex) {
                output = "Unhandled error occured: " + ex.Message;
                Log(output, false);
                return -1;
            }
            finally {
                if (rootWeb != null) {
                    rootWeb.Dispose();
                }
                if (siteCollection != null) {
                    siteCollection.Dispose();
                }
            }
        }

        ///
        /// Go through a web, all lists and sync with the source content
        /// type.
        /// Go recursively through all sub webs.
        ///
        ///
        ///
        private void ProcessWeb(SPWeb web, SPContentType sourceCT) {
            //Do work on lists on this web
            Log("Processing web: " + web.Url);

            //Grab the lists first, to avoid messing up an enumeration
            // while looping through it.
            List lists = new List();
            foreach (SPList list in web.Lists) {
                lists.Add(list.ID);
            }

            foreach (Guid listId in lists) {
                SPList list = web.Lists[listId];

                if (list.ContentTypesEnabled) {
                    Log("Processing list: " + list.ParentWebUrl + "/"
                         + list.Title);

                    SPContentType listCT =
                                         list.ContentTypes[ContentTypeName];
                    if (listCT != null) {
                        Log("Processing content type on list:" + list);

                        if (UpdateFields) {
                          UpdateListFields(list, listCT, sourceCT);
                        }

                        //Find/add the fields to add
                        foreach (SPFieldLink sourceFieldLink in
                                               sourceCT.FieldLinks) {
                          if (!FieldExist(sourceCT, sourceFieldLink)) {
                            Log(
                              "Failed to add field "
                              + sourceFieldLink.DisplayName + " on list "
                              + list.ParentWebUrl + "/" + list.Title
                              + " field does not exist (in .Fields[]) on "
                              + "source content type", false);
                          }
                          else {
                            if (!FieldExist(listCT, sourceFieldLink)) {
                              //Perform double update, just to be safe
                              // (but slow)
                              Log("Adding field \""
                                 + sourceFieldLink.DisplayName
                                 + "\" to contenttype on "
                                 + list.ParentWebUrl + "/" + list.Title,
                                   false);
                              if (listCT.FieldLinks[sourceFieldLink.Id]
                                                                != null) {
                                listCT.FieldLinks.Delete(sourceFieldLink.Id);
                                listCT.Update();
                              }
                              listCT.FieldLinks.Add(new SPFieldLink(
                                      sourceCT.Fields[sourceFieldLink.Id]));
                              listCT.Update();
                            }
                          }
                        }

                      if (RemoveFields) {
                            //Find the fields to delete
                            //WARNING: this part of the code has not been
                            // adequately tested (though
                            // what could go wrong?   ... )

                            //Copy collection to avoid modifying enumeration
                            // as we go through it
                            List listFieldLinks =
                                                  new List();
                            foreach (SPFieldLink listFieldLink in
                                                     listCT.FieldLinks) {
                                listFieldLinks.Add(listFieldLink);
                            }

                            foreach (SPFieldLink listFieldLink in
                                                        listFieldLinks) {
                                if (!FieldExist(sourceCT, listFieldLink)) {
                                    Log("Removing field \""
                                       + listFieldLink.DisplayName
                                       + "\" from contenttype on :"
                                       + list.ParentWebUrl + "/"
                                       + list.Title, false);
                                    listCT.FieldLinks.Delete(
                                                        listFieldLink.Id);
                                    listCT.Update();
                                }
                            }
                        }
                    }
                }
            }

            //Process sub webs
            foreach (SPWeb subWeb in web.Webs) {
                ProcessWeb(subWeb, sourceCT);
                subWeb.Dispose();
            }
        }

      ///
      /// Updates the fields of the list content type (listCT) with the
      /// fields found on the source content type (courceCT).
      ///
      ///
      ///
      ///
      private void UpdateListFields(SPList list, SPContentType listCT,
                                    SPContentType sourceCT) {
        Log("Starting to update fields ", false);
        foreach (SPFieldLink sourceFieldLink in sourceCT.FieldLinks) {
          //has the field changed? If not, continue.
          if (listCT.FieldLinks[sourceFieldLink.Id]!= null
               && listCT.FieldLinks[sourceFieldLink.Id].SchemaXml
                  == sourceFieldLink.SchemaXml) {
            Log("Doing nothing to field \"" + sourceFieldLink.Name
                + "\" from contenttype on :" + list.ParentWebUrl + "/"
                + list.Title, false);
            continue;
          }
          if (!FieldExist(sourceCT, sourceFieldLink)) {
            Log(
              "Doing nothing to field: " + sourceFieldLink.DisplayName
               + " on list " + list.ParentWebUrl
               + "/" + list.Title + " field does not exist (in .Fields[])"
               + " on source content type", false);
            continue;

          }

          if (listCT.FieldLinks[sourceFieldLink.Id] != null) {

            Log("Deleting field \"" + sourceFieldLink.Name
                + "\" from contenttype on :" + list.ParentWebUrl + "/"
                + list.Title, false);

            listCT.FieldLinks.Delete(sourceFieldLink.Id);
            listCT.Update();
          }

          Log("Adding field \"" + sourceFieldLink.Name
              + "\" from contenttype on :" + list.ParentWebUrl
              + "/" + list.Title, false);

          listCT.FieldLinks.Add(new SPFieldLink(
                                     sourceCT.Fields[sourceFieldLink.Id]));
          //Set displayname, not set by previus operation
          listCT.FieldLinks[sourceFieldLink.Id].DisplayName
                      = sourceCT.FieldLinks[sourceFieldLink.Id].DisplayName;
          listCT.Update();
          Log("Done updating fields ");
        }
      }

      private static bool FieldExist(SPContentType contentType,
                                                     SPFieldLink fieldLink)
        {
            try
            {
                //will throw exception on missing fields
                return contentType.Fields[fieldLink.Id] != null;
            }
            catch(Exception)
            {
                return false;
            }
        }

        private void Log(string str, bool verboseLevel) {
            if (Verbose || !verboseLevel) {
                Console.WriteLine(str);
            }
        }

        private void Log(string str) {
            Log(str, true);
        }

        ///
        /// Parse the input settings
        ///
        ///
        ///
        private bool GetSettings(StringDictionary keyValues) {
            try {
                ProvidedUrl = keyValues["url"];
                //test the url
                new Uri(ProvidedUrl);

                ContentTypeName = keyValues["contenttype"];
                if (string.IsNullOrEmpty(ContentTypeName)) {
                    throw new ArgumentException("contenttype missing");
                }

                if (keyValues.ContainsKey("removefields")) {
                    RemoveFields = true;
                }

                if (keyValues.ContainsKey("verbose")) {
                    Verbose = true;
                }

                if (keyValues.ContainsKey("updatefields"))
                {
                    UpdateFields = true;
                }
                return true;
            }
            catch (Exception ex) {
                Console.Out.WriteLine("An error occuring in retrieving the"
                    + " parameters. \r\n(" + ex + ")\r\n");
                return false;
            }
        }

        ///
        /// Output help to console
        ///
        ///
        ///
        public string GetHelpMessage(string command) {
            StringBuilder helpMessage = new StringBuilder();

            // syntax
            helpMessage.AppendFormat("\tstsadm -o {0}{1}{1}", command,
                                                 Environment.NewLine);
            helpMessage.Append("\t-url " + Environment.NewLine);
            helpMessage.Append("\t-contenttype " + Environment.NewLine);
            helpMessage.Append("\t[-removefields]" + Environment.NewLine);
            helpMessage.Append("\t[-updatefields]" + Environment.NewLine);
            helpMessage.Append("\t[-verbose]" + Environment.NewLine);

            // description
            helpMessage.AppendFormat("{0}This action will propagate a site"
                + " content type to all list content types within the "
                + "site collection.{0}Information propagated is field "
                + "addition/removal.{0}{0}", Environment.NewLine);
            helpMessage.AppendFormat("{0}Søren Nielsen (soerennielsen."
                + "wordpress.com){0}{0}", Environment.NewLine);

            return helpMessage.ToString();
        }
    }
}

Final Comments

I’ve made zero attempts to optimize the code. It doesn’t really matter how long it takes, does it? Give it 10 minutes till a couple of hours for huge site collection (I’ve tested with about 400 sub sites).

I recommend that you use the verbose flag and pipe the output to a file, so that you can review that it did everything correctly.

The code does not handle site content types on sub sites I’ll probably add it fairly soon if I need it or time permits (does it ever?)

License

Use the above code freely, with two conditions:

1. Leave my name and link in there
2. Report bug and improvements back to me

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