MOSS 2007 and Software Product Lines

Since my last post I've been busy extending the idea of generating features to the domain of list templates. This proved to be more difficult, since lists don't come with the nicely formatted xml in the content database, that provided me an easy solution generating content types.

On the other hand, the gains would also be bigger, since creating a list without the help of a generator involves modifying a schema.xml file, which has a rather intimidating complexity (to me at least).

What I wanted to do, is creating lists in a two or three step process:

1. Creating a list using the MOSS GUI;
2. Optionally editing the Forms, by using the Sharepoint Designer;
3. Generate a ListTemplate Feature with Feature.xml, Elements.xml, Schema.xml and Forms (typically AllItems.aspx, DispForm.aspx, EditForm.aspx and NewForm.aspx), and other forms that result from the creation of additional views in the MOSS gui.

Getting the generated schema.xml right wasn't particularly easy. I used the SchemaXml properties for views, forms etcetera, but none of them where usable right out of the box. In the end however, I succeeded. I've been testing against a dozen or so lists, and the features are generated without any problems. I have also not tested incorporating forms that are changed with the Sharepoint designer. This will be the topic for one of my next posts.

I think that generators should provide as much extensibility points as possible to be of real value in a product line. Although not optimal at this time, you'll be able to adjust/influence generation in the following ways (roughly from minor to major effort):

• Adjusting the list within the MOSS Gui, like creating views, altering sort-orders etcetera;
• Adjust attributes from the Feature Generator Gui. This includes the major attributes like name, description, FeatureID, and also paths/urls that are defined in the schema.xml;
• Adjusting forms in Sharepoint Designer;
• Altering generated files by hand (the painstaking process you know so well).
• Altering the code in the generator by using Visual Studio;

Below are the steps neede to create a list from the Gui in MOSS and then generate it as a feature.

1 Create a list in the MOSS GUI

2 Customize the list

In the settings page for a list you may add new columns, change their order or create new views. In the General settings, you can change the title and description, the versioning settings and the content types for the list (first allow content types under advanced settings). Changes to items under the Permissions and Management and the Communication sections are not supported at this time.

3 Select creating a New List  Template

Select File, then New, then List Feature

.

4 Select a List Instance

Paste the URL to your top level site in the SiteCollection Url box. Then Select one of the sites in the Site dropdown.

From the Lists, select the instance for which you want to create a feature.

5 Create the Feature files

The properties of the selected list will now appear in the List Feature Creation Form. You can alter Title, Description, Scope and Version.

For the FeatureID you have a few options. By default, a new GUID is generated for the FeatureID. If you want to keep the original FeatureID, uncheck the Create New Feature Checkbox. If you want to control the creation of the GUID yourself (if you need the GUID in other features, for example) you can do so by pressing the New button to the right of the FeatureID textbox.

In the middle section, you can customize the creation of the schema a little. To do this, check the Override Defaults CheckBox. Note that this section does not show the attributes of the List instance, because the values provide in a List instance are not valid for a schema.xml for a List Template.

The defaults in this section will create a Folder with the same name as the the rootfolder for the feature. The Schema.xml and the Forms will be created in this directory.

You can't change the document template, fields or contents types at this time. It is assumed that you do this in the MOSS GUI. In fact, if the properties are not what you would have liked, you can change the list in the MOSS GUI, and return to step 4. All your changes will be visible right away.

Finally, change the path, and press Create Features. In the specified direction you will now find you Feature.xml, Elements.xml and in the subfolder below, a schema.xml, and files for manipulating the items and the views. This typically includes an AllItems.aspx, a DispForm.aspx, an EditForm.aspx and a NewForm.aspx, and an extra form for each view you added in the MOSS GUI.

Wrap up

I do not provide extensive customization options in the MOSS Feature Generator Gui, since the idea of it all is that you will do the editing withing the MOSS GUI.

 Since I have now generators for Content Types (Columns included) and List Templates, I changed the solution to support both. And ofcourse I had to rename Content Type Feature Creator to something more generic like MOSS Feature Generator.

In the next few days I'll be concentrating on the integration of the features. A problem at this time is that the generation of the Fields and the ListTemplate is not related. So you will have to adjust FeatureID's by hand when you want to export both Fields and ListTemplate.

A dozen of lists to test is not nearly enough. So if you have functionality that is not supported (or downright errors), please drop me a line. I think that, if we combine forces, we should be able to drastically reduce development time for Sharepoint 2007 solutions, making it an even better alternative for customers. In the attachment ( the rather tiny link below) you will find the executable. I'll put the Visual Studio solution in my next post. The attachment, by the way, will only appear if you select this article, not if you view this article in the blog.

Alfred 

Features for Content Types and Site Columns can be quickly generated by using CTFC. There are basically two main steps involved:

1. Create features by using the MOSS 2007 User Interface
2. Generate features based on what I had created.

Please note however that in this version (1.1) is not tested rigidly. It is more a prove of concept, to demonstrate and evaluate the possibilities and limitations.

I will now explain the steps in a little more detail.

1       Create features by using the MOSS 2007 User Interface

This is the process by which a power user might create a user from the MOSS 2007 user interface. A number of different options exist for creating the Content Type,  some of which are supported out of the box, and some are not.

Supported are the inheritance of existing Content Types, and the usage of newly created Custom Site columns, for which a separate feature will be generated.

Some other advanced properties have not been tested, for instance the coupling to a workflow.

The creation of custom site columns and content types in the user interface is described by a number of people, for instance Shady KhorShed at http://shadiesm.blogspot.com/2007/11/moss-create-site-column.html, or Jan Tielens at http://weblogs.asp.net/jan/archive/2006/05/09/445763.aspx

2 Generate features based on what I had created.

The generation of features from the stuff you created in the MOSS user interface involves two steps.

Database form

In the database form, data for columns and content types is retrieved from the database by following steps:

• a) Specify the path to your content database, You can find this path by opening the Central Administration, selecting Application Management, then "Create New Web Application" and finding the server name. This is a bit counterintuitive, but you can not find the server by inspecting the existing web application(s). Then, again from the Application Management tab, select Content Databases. Select the web application, and you'll get the content database(s). If you provided logical names, you'll see here which one is your target.
• b) Press "Load", and if your connectionstring was OK, you'll see content types and columns you created in step 1, appear in the lists.
• c) Select the content type for which you want to create a feature and press the Next button. The feature form will now open.

Feature form

In the features form, you see the properties of both the custom columns and the content type features.

• a) Optionally you may change the settings supplied;
• b) Select a path to create the feature to
• c) Press the Create Features button and the features will be created to the specified path

 In the attachment you will find the executable program, help file and sources

 Alfred

Update: In my new post, I show you a new tool for both the creation of features for content types and columns as for lists

 Alfred

I was looking for information on the generation of features, but I could not find any information yet. Splendid! Good start for some coding. What I wanted to do is:

1. Create features by using the MOSS 2007 User Interface
2. Generate features based on what I had created.

By the way, if you have never created a Content Type feature, it would help you understand the text below to glance over how its done, for example by reading this post by Ton Stegeman: /tonstegeman/archive/2006/07/19/creating-contenttypes-in-sharepoint-2007-by-using-a-feature.aspx

Using custom site columns and custom content types as a start, it appeared to be possible to decrease development time significantly. I've not gone through a formal testing process, and I needed some hacks. So I expect that some more issues will come up. But I do not think I'll ever code columns or content type features from scratch again. It's also a handy tool for to study more complex content types like those inheriting from other content types.

Looking in the content database, I noticed that with a "select definition from ContentTypes where definition is not null" I could retrieve both columns I had create in the MOSS user interface, and content types I had created there. I was a little surprised that there was actually XML in the table, resembling closely the XML I used to type in to create my custom site columns and custom content types.It was easy enough to grab the data from the content database and generate feature.xml and elements.xml files from it (never try to write to the content database!). The files thus generated however refused to be activated. I had to tidy up the XML to get them working.

Well to describe what I did in a more organized manner:

1 Use Sql Server to retrieve the URL for the MOSS content database.

I used this connectionstring: "Data Source=VPCWIN2003R2;Initial Catalog=WSS_Content_8080;Integrated Security=SSPI";

2 Read the relevant data from the database, and fill two lists

Since both columns and content types are in the same table, I filtered them based on thier element name.

                SqlCommand cmd = new SqlCommand("select definition from ContentTypes where definition is not null", connection);
                SqlDataReader rdr = cmd.ExecuteReader();

                while (rdr.Read())
                {
                    string xmlString = (string)rdr[0];

                    string nodeType = XmlHelper.GetElementName(xmlString);
                    if (nodeType.Equals("Field"))
                    {
                        lstColumns.Items.Add(xmlString);
                    }
                    else
                    {
                        this.lstContentTypes.Items.Add(xmlString);
                    }
                }

3 Create a feature.xml file for the columns 

I used values I keyed in from a form to generate a valid feature.xml (more on the little tool I created below)

4 Create an elements.xml file for the columns

From all columns I created in the Moss User Interface, I had to filter those relevant for the selected content type. For this I could just iterate over the the <FieldRef> elements in the content type and verify select the column if there was a match.

         //returns the columns that are relevant for the content type
        private static string GetRelevantFields(string contentType, string[] columns)
        {
            string retVal = "";
            XPathNodeIterator it = GetRootNodeIteratorFromString(contentType);
            XPathNodeIterator it2 = it.Current.SelectDescendants("FieldRef","",false);
            while (it2.MoveNext())
            {
                string id=it2.Current.GetAttribute("ID", "");
                for (int i = 0; i < columns.Length; i++)
                {
                    if (columns.Contains(id))
                    {
                        string fieldString = columns.Insert(6, " xmlns = "http://schemas.microsoft.com/sharepoint/"");
                        retVal += fieldString;
                    }
                }
            }
            return retVal;
        }

Unfortunately, when I added the XML thus obtained to my elements.xml file, I received an error when installing the feature. It appeared that, when you do not add a xml namespace, an empty one is added to the xml when you add the node. That is why I had to insert the right namespace to the columns, before adding them to the return value.

 5 Create the content type feature.xml file

This was equivalent to the columns feature.xml file

6 Create the content type elements.xml file

This would have been just the creation of a xml file from the data in the content database, but then there proved to be some issues:

a) An empty namespace was added, as decribed in (4). I added a namespace as a property (I have not been doing XML in code for some years, there'll be a more elegant way, I bet)

b) For content types that derived from the Page content type, or a sub type of Page, a number of attributes were introduced with empty values (Customization, PIAttribute, PITarget, to name some). I did not understand these properties, so I removed them by using a regular expression

c) There seemed to be a problem with the xml of the <XmlDocument> nodes, so I removed them by using a regular expression

7 Install features

I copied the feature directories to Features folder and installed them by using stsadm as described on http://msdn2.microsoft.com/en-us/library/ms442691.aspx. I have not automated this part yet.

I tried a dozen or so content types, which could all be created and activated. I did not try using each and every column or content type from the User Interface, so just consider this a prove of concept. 

Since increasing productivity of MOSS solutions is one of my main interests, any feedback would be welcome.

Alfred