Corey Roth [MVP] : LINQ, SharePoint, LINQ to XML

A simple way to programmatically create SharePoint security groups

CoreyRoth — Mon, 08 Mar 2010 17:12:50 GMT

When it comes to SharePoint deployments, I try to automate everything I can. I don’t like manual steps especially when it comes to setting up security. A common task when deploying any sites is setting up security in some manner. Today I am going to cover how to easily store definitions your SharePoint security groups in an XML file. We’ll use LINQ to XML to make reading the file a breeze, and then we’ll use the SharePoint object model to create the groups and add users (or AD groups). I’ve blogged on how to create a group before, but we’re going to take this a step further by giving you code that you can easily add to a feature receiver or console application. First let’s take a look at the XML file we’re going to use.

<?xml version="1.0" encoding="utf-8" ?>
<Groups>
  <Group Name="My Custom Read Group" Owner="SHAREPOINT\GroupOwner" Description="Readonly Permission Group" PermissionLevel="Read">
    <User Name="SHAREPOINT\TestUser1" />
    <User Name="SHAREPOINT\TestGroup1" />
    <User Name="SHAREPOINT\TestGroup2" />
  </Group>
  <Group Name="My Custom Contributors Group" Owner="SHAREPOINT\GroupOwner" Description="Contributors Permission Group" PermissionLevel="Contribute">
    <User Name="SHAREPOINT\TestGroup3" />
  </Group>
</Groups>

In this file, I am defining two SharePoint groups. One that will have read access and one that will have contribute access. I store the required information needed by the Add method on the SPGroupCollection object. I then have one or more User elements with the name of my Active Directory user or group. I tried to keep my XML schema pretty simple. You can customize it obviously how you want, you would just have to alter your LINQ queries.

Let’s take a look at the code we need to make this happen. I won’t go into as much detail of the object model since I went into it pretty well on my last post. We’ll just focus on how we use LINQ to XML to read the information we need and then have it create our groups. My method is called CreateGroups and it takes an SPWeb object and a string with the filename of the XML document.

private void CreateGroups(SPWeb currentSite, string groupsFilename)
{
    // get the xml document from the feature folder
    XDocument groupsXml = XDocument.Load(groupsFilename);
 
    // create a new anoynmous type with the group data
    var groups = from sharePointGroup in groupsXml.Root.Elements("Group")
                select new
                {
                    Name = sharePointGroup.Attribute("Name").Value,
                    Owner = sharePointGroup.Attributes("Owner").Any() ? sharePointGroup.Attribute("Owner").Value : null,
                    Description = sharePointGroup.Attributes("Description").Any() ? sharePointGroup.Attribute("Description").Value : string.Empty,
                    PermissionLevel = sharePointGroup.Attributes("PermissionLevel").Any() ? sharePointGroup.Attribute("PermissionLevel").Value : null,
                    Users = sharePointGroup.Elements("User").Any() ? sharePointGroup.Elements("User") : null
                };
 
    // iterate through the groups and create the groups
    foreach (var sharePointGroup in groups)
    {
        // only create the group if it does not exist
        if (!ContainsGroup(currentSite.SiteGroups, sharePointGroup.Name))
        {
            // add the owner to the web site users
            currentSite.EnsureUser(sharePointGroup.Owner);
 
            // add the group
            currentSite.SiteGroups.Add(sharePointGroup.Name, currentSite.SiteUsers[sharePointGroup.Owner],
                currentSite.SiteUsers[sharePointGroup.Owner], sharePointGroup.Description);
        }
 
        // add the users to the group
        AddUsersToGroup(sharePointGroup.Name, sharePointGroup.Users, currentSite, sharePointGroup.PermissionLevel);
    }
}

This seems like kind of a big method at first, but it’s really not that bad. To keep things simple, I haven’t included any exception handling code. We are really just querying the XML document, iterating through each group element inside of it, creating the groups, and then adding the users to the group. The first line of code just creates an XDocument object. We then construct a LINQ to XML query. What we want is to return data from each Group element in the document. The Add method doesn’t like nulls, so we check for them and use string.Empty if the value does not exist in the file. The one case where I don’t do this is for the Name of the group. If that is not present, I would rather the process throw an exception. As for the Users assigned to the group, I grab all of them and add them to our anonymous type like this.

Users = sharePointGroup.Elements("User").Any() ? sharePointGroup.Elements("User") : null

This gives us an IEnumerable<XElement> that we can pass to a method later to add each Active Directory user (or group) to the SharePoint group. Once we execute the query, we iterate through each group element. The first thing we have to do is make sure that the group does not exist. Of course there is no way to do that other than using the try/catch technique. I will usually wrap this in an extension method, but for today’s purpose, we’ll just call a method to check.

private bool ContainsGroup(SPGroupCollection groupCollection, string index)
{
    try
    {
        SPGroup testGroup = groupCollection[index];
        return true;
    }
    catch (SPException e)
    {
        return false;
    }
}

Lame I know. I’m so happy there are ways to get around this in SharePoint 2010. Then this starts to look like code from the previous post. We call .EnsureUser to make sure the domain account of the group owner is registered with the site. We then just call the Add method with the Name, Owner, default user, and description. Again there is more info on the previous post about that method call. Assuming the group is created, we can then add the users to the group. We call a new method AddUsersToGroup which takes the groupName, the users element, an SPWeb, and the permission level.

The first thing we do is query the names of the Active Directory users (or groups). Here we are just grabbing it from the Name attribute of the User element. I probably could have condensed this query, but at least it’s easy to read. We then add each user (or group) from the User elements to the group. If you are curious about the empty parameters, take a look at the previous post. If you are going to run into an exception, it’s going to be here. If the group failed to be created or if the user does not exist (i.e.: you typed it in the XML file wrong), this line will throw an exception.

private void AddUsersToGroup(string groupName, IEnumerable<XElement> users, SPWeb currentSite)
{
    // select the username from the xml document
    var userList = from user in users
                   select new
                   {
                       Name = user.Attribute("Name").Value
                   };
 
    // add the users to the sharepoint group
    foreach (var user in userList)
    {
        currentSite.SiteGroups[groupName].AddUser(user.Name, string.Empty, user.Name, string.Empty);
    }
}

Now, we’re almost done. The last thing we need to do is set the permission level on the group. This is where we specify whether the group has readonly, contribute, full control, etc access to the site. Be sure and get the name on the permission level right otherwise you will get an exception. I’ve also blogged about how to assign permission levels before. Today’s post is really just a great practical use of putting together the things I have posted on before.

private void SetRoleDefinitionBinding(string groupName, SPWeb currentSite, string permissionLevel)
{
    // add the read role definition to the site group
    SPRoleAssignment roleAssignment = new SPRoleAssignment(currentSite.SiteGroups[groupName]);
    roleAssignment.RoleDefinitionBindings.Add(currentSite.RoleDefinitions[permissionLevel]);
    currentSite.RoleAssignments.Add(roleAssignment);
    currentSite.Update();
}

Effectively you create a new SPRoleAssignment by passing it a SPGroup object. You then add a binding using the existing RoleDefinitions on the site. You then add the assignment to the site and of course call .Update() so things get saved.

That’s really all there is to it. This is a great use of combining information from my previous posts into something that you can use everyday to set security on your sites. How you execute this code is up to you. I’ve used it in a feature receiver and in a console application before. Setting up security through the UI is very slow and painful. Once you create it on one server, there is no way to move it to another server and that’s not a lot of fun. This should help you with that and eliminate those nasty manual steps in your deployment process.

Linq to XML and Deleting Lists on Feature Deactivation

CoreyRoth — Thu, 24 Sep 2009 20:04:04 GMT

A few months ago, I discussed how to use LINQ to XML to parse your elements.xml file to delete any files that you may have deployed on feature activation. Today I have decided to reuse this concept to delete any lists that I have created when I deactivate a feature? Now you may ask, “why would I want to delete a list when a feature is deactivated? I’ll lose all of my data in that list!” My answer is: Yes, of course you will, but sometimes when building a feature to deploy a list(s), you want to delete the list each time before you deploy a new version of it. During development this is a huge time saver. Right now, I am working on a feature that deploys four document libraries. This means I have to manually delete each one. That is a huge waste of time, but what is nice is that we can reuse the concept above with LINQ to XML and delete lists instead.

The code is quite similar. Have a look. We first, write some code to get the path to the elements.xml file. This code snippet assumes, it is always named Elements.xml. Maybe in the future, I will have it look in the feature.xml file, get all of the ElementManifest definitions and then delete whatever it finds in each file. For now though, we assume, you can change the path as needed.

public override void FeatureDeactivating(SPFeatureReceiverProperties properties)
{
    using (SPWeb currentSite = (SPWeb)properties.Feature.Parent)
    {
        string elementsPath = string.Format(@"{0}\FEATURES\{1}\Elements.xml", SPUtility.GetGenericSetupPath("Template"), properties.Definition.DisplayName);
        DeleteLists(currentSite, elementsPath);
    }
}

From here, it passes a reference to the current SPWeb and the path to the XML document. The path to the elements.xml file is used to populate an XDocument which we can then query with LINQ to XML.

private void DeleteLists(SPWeb currentSite, string elementsPath)
{
    try
    {
        XDocument elementsXml = XDocument.Load(elementsPath);
        XNamespace sharePointNamespace = "http://schemas.microsoft.com/sharepoint/";
 
        // get each URL to each list
        var listInstances = from module in elementsXml.Root.Elements(sharePointNamespace + "ListInstance")
                        select new
                        {
                            ListUrl = (module.Attributes("Url").Any()) ? module.Attribute("Url").Value : null,
                        };
 
        // iterate through each list and delete it
        foreach (var listInstance in listInstances)
        {
            try
            {
                SPList currentList = currentSite.GetList(string.Format("{0}/{1}", currentSite.Url, listInstance.ListUrl));
                currentList.Delete();
            }
            catch (System.IO.FileNotFoundException e)
            {
                // this exception is thrown if the list does not exist
            }
        }
 
        // update the site
        currentSite.Update();
    }
    catch
    {
    }
}

This code is quite similar to that used in my other post, however instead of looking for Module elements we are looking for ListInstance elements. It creates a list of those Urls to each list and iterates through them. For each list it finds, it deletes the list. I’ve written code in the past to manually delete lists, I create by name. That works fine, but the name of each list has to be maintained. Now, I just attach this to any feature I am working on and it deletes any list (or lists) that I throw at it. More than likely this isn’t something you want once you go to production, but it will save you a ton of time during development.

How I used LINQ to XML to Create Document Library Folders

C-Dog's .NET Tip of the Day — Thu, 17 Jan 2008 23:29:24 GMT

I have been doing a lot of document library work lately and in my work I had a need to create a series of subfolders in the document library using a particular custom content type. This meant I was going to need to write a little code. I decided to keep...(read more)