Saturday, November 26, 2011

Dynamic class system in C# 4.0

The "dynamic" type (rather pseudo-type or keyword) is a new feature in the latest version of C# - 4.0. Its purpose is to enable an easier interoperability with dynamic type languages and COM components and is part of the new DLR system introduced in the .NET Framework 4.0. In addition to the new "dynamic" type there are two interesting new built-in .NET classes that allow you to do some sort of dynamic type programming with C# - the ExpandoObject class and the DynamicObject class. Using the "dynamic" type/keyword and the ExpandoObject you can do things like this:
dynamic sampleObject = new ExpandoObject();
sampleObject.number = 10;
sampleObject.Increment = (Action)(() => { sampleObject.number++; });

You can add dynamically member variables to the "dynamic" instance and also methods by assigning delegates or anonymous methods to instance members (you can also assign and use events in the same manner). These tricks are possible and the C# compiler doesn't raise compilation errors exactly because of the "dynamic" keyword. It ensures that  these assignments, member variable usages and method invocations are not checked during compile time but all that happens at run time. The dynamic dispatching semantics are implemented by the ExpandoObject class. It implements a special .NET interface called IDynamicMetaObjectProvider which is used as a bridge by the DLR for the correct routing of all these dynamic invocations and references at run time. It is possible to create custom classes implementing this interface but it is actually easier to do that by inheriting the second class that I mentioned - the DynamicObject class. The DynamicObject class is an abstract class and if you inherit your class from it you will be able to easily implement your custom dynamic member dispatching logic by overriding one or more of its virtual methods.
I will not go into further detail about the "dynamic" type/keyword and the ExpandoObject as this is quite a broad subject and there are many in depth articles already available in MSDN. Instead I will go directly to the subject of this posting which is the simple dynamic class system for C# 4.0 that I implemented.
First, let me briefly explain as to why I came with the idea of implementing a dynamic class system in C#. The main reason was to do it just for fun and to prove (at least to myself) the expression power of C#. As a side note this means that this implementation is not intended for any serious usage, I coded the whole thing in just a couple of hours, so it lacks any performance optimizations whatsoever, it doesn't support multi threading and is not thoroughly tested. So, basically the answer to the question, why would there be any need to add dynamic classes support to a powerful static type language like C# is the plainly sounding - just to demonstrate that it is possible.
And the immediate reason to do this was that when I was reading the MSDN documentation about the ExpandoObject class I started wondering why they made it only possible to add dynamically members to a single instance/object only instead of providing support for dynamic classes with which to enable the creation of many instances having a predefined set of members simultaneously. Of course, this can be somehow emulated with the ExpandoObject itself - one only needs to create a "factory" method that creates and returns instances of the ExpandoObject "initialized" with the desired set of members but I wanted something more coherent and self-contained. And also some real class support with at least some of the standard class system features like inheritance, polymorphism, etc.
You can download the implementation of the dynamic class system from here - this is a small console application that defines two public classes - "Class" and "ClassDefinition" (quite descriptive names) which contain the whole logic of the dynamic class system. The application contains also a big demonstration section with lots of verbose comments describing the details of the usage of the dynamic classes - I will have this entire section pasted at the end of this posting, so that you can get an idea of the syntactic peculiarities of these "dynamic classes". But before doing that let me quickly list the main features of this custom dynamic class system:
  • uses only C# 4.0 syntax without any external or extra language declarations or configurations
  • supports simple class inheritance - a class can inherit only one base class
  • classes are defined with imperative statements (as opposed to the declarative syntax for normal/static C# classes)
  • supports simple polymorphism - all methods are treated as virtual
  • supports class constructors and constructor overloading
  • supports method overloading - you can have two or more member methods with the same name but with different set of parameters
  • supports the "self" keyword for referencing member variables/methods from member methods (analogue to the C#'s native "this" keyword)
  • supports the "super" keyword for referencing methods defined in the parent class (if available)
  • objects (class instances) are "open" - you can initialize and use additional member variables and methods that are not defined in the class (similarly to the objects in JavaScript and the ExpandoObject itself)
  • class definitions are also "open" - you can extend the definition of any class at any later moment adding new member variables and methods (slightly influenced by Ruby). The new methods are immediately available in all class instances even those created before the extension of the class definition.
  • relaxed rules for uninitialized member variables and methods. You can reference not initialized member variables and this will not raise an error - but the value returned will be null. You can call not initialized (not existing) methods and this will not raise an error either - the invocation will do nothing and will return null.
  • doesn't support events
  • doesn't support access modifiers - all members are treated as public and accessible from any context
And here is the demonstration section describing the "syntax" of the dynamic class system:

// 'Class' is a static class with one static method - you can define dynamic classes with it: Class.DefineClass
// you specify the class name, the base class (null for none) and an Action delegate (lambda expression) that defines the class' members
Class.DefineClass(new ClassDefinition()
    ClassName = "BaseClass", 
    Variables = (def) =>     {
         // two member variables
         def.Register1 = 1;
         def.Register2 = 2;
     Methods = (def, self) =>     {
         // the Init method is used as a constructor
         def.Init = new Action<intint>((a, b) => { self.Register1 = a; self.Register2 = b; });
         // define an Add method
         def.Add = new Func<intintint>((a, b) => a + b);
         // define an overload of the Add method that sums the member properties Register1 and Register2 - note the usage of the "self" lambda parameter
         def.Add = new Func<int>(() => self.Register1 + self.Register2);
         def.ProxyAdd = new Func<int>(() => { Console.Write("BaseClass.ProxyAdd calling Add(): "); return self.Add(); });
// now have a look at the static property "New" of the Class class, which is of type ... dynamic
// and we can call methods on this "New" dynamic object which will return instances of our custom dynamic classes with the same name // let's create an instance of the dynamic class Test calling its constructor that accepts a string paramter
// but ... we haven't defined a class named "Test" let alone a constructor of the "Test" class
// still the local variable c1 gets initialized with a "dynamic" instance which behaves pretty much like the standard ExpandoObject class
dynamic c1 = Class.New.Test("test");
// it doesn't have any properties but we can add one
c1.var1 = "test";
// this will print "test"
// what about the "var2" property - it hasn't been initialized so c1.var2 is simply null
Console.WriteLine(c1.var2 ?? "this is null");
// we don't have any methods in c1, but we can call whatever methods we want - they will all return null (and will do nothing of course)
Console.WriteLine(c1.test(1, 2) ?? "this is null");
// let's now create an instance of the "BaseClass" class, which we have already declared. This would call the parameterless Init method of the class (if it existed)
dynamic c2 = Class.New.BaseClass();
// call its Add(int, int) method with two integer parameters - result is 2 + 2 = 4
Console.WriteLine(c2.Add(2, 2));
// call the Add() overload with no parameters - this sums the object's properties Register1 and Register2 which have their initial values: 1 + 2 = 3
// let's create another instance of the BaseClass class. This will call its Init(int, int) method that takes two integer parameters.
dynamic c3 = Class.New.BaseClass(7, 8);
// calling the parameterless Add() overload will sum the Register1 and Register2 properties which were initialized to 7 and 8 respectively: 7 + 8 = 15
// the same: 7 + 8 = 15
// now let's define a new class that inherits the BaseClass class
ClassDefinition() {
     ClassName = "DerivedClass",
     BaseClassName = "BaseClass",
     Variables = (def) =>     {
         // declare a new property
         def.Register3 = 3;
     Methods = (def, self) =>     {
         // declare a constructor that accepts three integers
         // note the usage of the self.super expression - we can call methods from the base class this way (not necessary in this case since the base method accepts two parameters and the new method - three, so the new method doesn't hide the overload in the base class and it can be called simply with self.Init(int, int))
         // note that the constructor of the base class is called explicitly
         def.Init = new Action<intintint>((a, b, c) => { self.super.Init(a, b); self.Register3 = c; });
         // redefining the parameterless Add() method, this one will hide the parameterless Add() method in BaseClass - to call the base class implementation we need to use self.super.Add()
         // we call both Add overloads of BaseClass - first to sum Register1 and Register2 and then to sum the result with Register3
         def.Add = new Func<int>(() => self.super.Add(self.super.Add(), self.Register3));
// here is an instance of the DerivedClass class (no constructor will be called since we don't have a parameterless Init() method)
dynamic c4 = Class.New.DerivedClass();
// this will invoke the DerivedClass.Add() implementation which sums Register1, Register2 and Register3: 1 + 2 + 3 = 6
// this will invoke the BaseClass.Add method(int, int) with two integer parameters (it hasn't been redefined in DerivedClass): 4 + 4 = 8
Console.WriteLine(c4.Add(4, 4));
// create an instance of DerivedClass ... using BaseClass.Init (int, int), which hasn't been redefined in DerivedClass
dynamic c5 = Class.New.DerivedClass(10, 11);
// calling DerivedClass.Add() will return: 10 + 11 + 3 = 24
// create another instance of DerivedClass - this will call Init(int, int, int) which was declared in DerivedClass
dynamic c6 = Class.New.DerivedClass(100, 200, 300);
// calling DerivedClass.Add() will return: 100 + 200 + 300 = 600
// calling BaseClass.ProxyAdd which calls Add() which is the DerivedClass.Add() version since c6 is DerivedClass
// Declare the DerivedClass class again? No, this will only extend the definition of DerivedClass - additional members can be added. No need to specify the base class again.
Class.DefineClass(new ClassDefinition {
     ClassName = "DerivedClass",
     Variables = (def) =>      {
         // add a new member property
         def.Register4 = 4;
     Methods = (def, self) =>     {
         // add a new constructor accepting 4 integer parameters - this one calls the constructor (with three integer parameters) from the first DerivedClass declaration
         def.Init = new Action<intintintint>((a, b, c, d) => { self.Init(a, b, c); self.Register4 = d; });
         // redefine again the parameterless Add method - this one will sum all properties: Register1, Register2, Register3 and Register4
         // note the tree calls to self.super.Add - two to self.super.Add(int, int) and one to self.super.Add()
         def.Add = new Func<int>(() => self.super.Add(self.super.Add(), self.super.Add(self.Register3, (self.Register4 ?? 0))));
// the c6 instance was created before the extending of the DerivedClass definition - but it will use the new version of DerivedClass.Add()
// it doesn't have the Register4 property initialized - it's value will be null (the Add() will add it as 0)
// 100 + 200 + 300 + 0 = 600
// set Register4 explicitly
c6.Register4 = 400;
// 100 + 200 + 300 + 400 = 1000
// again 100 + 200 + 300 + 400 = 1000
// c7 is created calling the constructor DerivedClass.Init(int, int, int) declared in the first definition of DerivedClass
dynamic c7 = Class.New.DerivedClass(1000, 2000, 3000);
// its Add method will now (as defined in the extension of DerivedClass) sum Register1, Register2, Register3 and Register4: 1000 + 2000 + 3000 + 4 = 6004
// c8 is created with the constructor DerivedClass.Init(int, int, int, int) defined in the second definition (extension) of DerivedClass
dynamic c8 = Class.New.DerivedClass(1000, 2000, 3000, 4000);
// its Add method will now sum Register1, Register2, Register3 and Register4: 1000 + 2000 + 3000 + 4000 = 10000
// we can call the parameterless constructor without the parenthesis
dynamic c9 = Class.New.DerivedClass;
// it's possible to call the Init method afterwards
c9.Init(10000, 20000);
// let's check that it's a different instance from c9 - see below
dynamic c10 = Class.New.DerivedClass;
// a built-in diagnostics method - dumping all member properties of the dynamic objects

Sunday, October 30, 2011

Deploy user controls in the SharePoint content database

Normally user controls (*.ascx files) in SharePoint are deployed with farm solutions and the preferred system  (hive) folder for that is the CONTROLTEMPLATES one. User controls can be used for various purposes – for form templates in SharePoint lists, with the new visual web part in SharePoint 2010 or simply to provide reusable visual bits that can be placed in more than one master page files of page layouts. User controls can be quite handy since they provide a nice separation of the presentation logic which is not directly available in the regular web controls – you can use the WebForms markup to produce your HTML output instead of having to deal with that in the code itself.

And to the subject of this posting – is it possible to have user controls (*.ascx) files directly in the content database of your SharePoint web application (site) instead of in the SharePoint hive folder (12/TEMPLATE/CONTROLTEMPLATES or 14/TEMPLATE/CONTROLTEMPLATES). The answer to this question is yes and I am going to demonstrate that shortly. But before that I would want to briefly discuss the motives and reasons that could justify the usage of user controls in the content database and also some possible advantages and disadvantages of this approach. This topic is actually a bit broader than suggested by the posting’s title and it is about the possibility of having a SharePoint custom application that doesn’t use custom assemblies and files deployed to the SharePoint hive folder. Sounds a bit like the new sandbox solutions available in SharePoint 2010 – this is to some extent so, though the code that can be executed is the normal farm version of the SharePoint object model. Unlike the sandbox solutions, there is also a big security implication that I will discuss shortly. The main motivation here is to have a way to place your code directly in your master pages or page layouts by using say the SharePoint designer. So, opposed to the usual way of deploying SharePoint farm solutions with “wsp” files, this is sorts of “SharePoint designer” development and deployment (the boundary between development and deployment with the SharePoint designer is almost non-existing). The other advantage here is that you can push all you code and code updates using the simple content deployment paths and jobs built-in functionality. The bottom line here is that if you use extensively the SharePoint designer and have a SharePoint environment with a publishing and production server using content deployment paths for content synchronization you can consider using this approach.

As for the question of how to use code directly in your master page files and page layouts (maybe you’ve done that many times already with the SharePoint designer) – the answer is simple – inline code blocks:

<script runat="server">

Two big notes here – the first one is the security issue that I mentioned above. Since it is very easy to insert a code block in a page using the SharePoint designer, there is an internal protection in SharePoint – this is the so called “safe mode” for parsing and processing of un-ghosted pages (pages that are in the content database). By default if you have a code block in a page that is un-ghosted (or was created directly in the content database) you will receive an error if you try to open the page. This can be overridden by a setting in the web.config file:

<PageParserPaths><PageParserPath VirtualPath="/_catalogs/masterpage/*" CompilationMode="Always" AllowServerSideScript="True" IncludeSubFolders="true" />

but keep in mind that this can be a serious security hole. Note the value of the “VirtualPath” attribute containing the location of the Master Page gallery with a wild card meaning that all your master page files and page layouts will be allowed to have code blocks. If you have a site collection under this server relative URL – “/sites/test-site” you will have to specify the full path to its Master Page gallery: “/sites/test-site/_catalogs/masterpage/*” (unless you don’t want to put something as unsecure as “/*”). For a detailed treatment of the SharePoint “safe mode” page processing, the configuration of the “PageParsePath” elements (and also of the “SafeControl” elements) check this MSDN article.

The second note is that the usage of code blocks as opposed to having the code in a code-behind assembly is not considered the very best and recommendable code practice. Apart from that the SharePoint designer is far from Visual Studio in terms of providing good IDE support for code development.

The placing of code blocks inside master pages and page layouts is maybe nothing new for most of you but the main idea of this posting is to demonstrate the using of user controls inside master pages and page layouts. And it will be the user control that will contain the inline code block in this case. Remember that the ascx file of the user control will reside in the content database (it can be uploaded to the Master Page gallery for instance), so it will be subject to the SharePoint “safe mode” processing mode too. And you will need to add some extra configuration bits to the web.config file so that your pages are allowed to use the user controls. You have two ways to enable this in the web.config – the first one is to add a “SafeControl” element like this one:

<SafeControl Src="/_catalogs/masterpage/*" IncludeSubFolders="True" Safe="True" AllowRemoteDesigner="True" SafeAgainstScript="True" />

Note that the value of the “Src” attribute should contain the full server relative URL of the target library in your site collection (e.g. for the “/sites/test-site site collection it will be /sites/test-site/_catalogs/masterpage/*”). The other way (much more unsecure) is to add an extra attribute to the “PageParsePath” element:


In this case you won’t need an extra “SafeControl” element.

Note also that although you can deploy your code files (pages and user controls) directly to the content database unlike the SharePoint 2010 sandbox solutions you will need to modify the web.config file of the containing web application, which has its own serious security implication, that I already pointed out.

And let me now demonstrate a sample user control that can be deployed (uploaded) to the Master Page gallery and used by page layouts (wpzone.ascx):

<%@ Assembly Name="Microsoft.SharePoint, Version=,Culture=neutral,PublicKeyToken=71e9bce111e9429c" %>
<%@ Assembly Name="Microsoft.SharePoint.Publishing, Version=, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Control Language="C#"  %>
<%@ Import Namespace="System.Collections.Generic" %>
<%@ Import Namespace="Microsoft.SharePoint" %>
<%@ Import Namespace="Microsoft.SharePoint.WebPartPages" %>
<script runat="server">
    protected string _wpZoneID;          
    public string WPZoneID { get { return _wpZoneID; } set { _wpZoneID= value; } }
    protected override void OnLoad (EventArgs args)
    protected override void Render (HtmlTextWriter writer)
         if (string.IsNullOrEmpty(_wpZoneID)) return;
         Control c = this.NamingContainer.FindControl (_wpZoneID);
         WebPartZone _zone = c as WebPartZone;
         if (_zone == null) return;
         SPWebPartManager mngr = SPWebPartManager.GetCurrentWebPartManager(this.Page) as SPWebPartManager;
         if (mngr == null) return;
         if (!mngr.GetDisplayMode().AllowPageDesign)
             // if we are in display mode - hide the zone control itself
             _zone.Visible = false;
             // and render the web parts directly
             foreach (WebPart part in _zone.WebParts)

And here is how you can use this control in a page layout (the technique is identical for master pages and regular web part pages) – first you need the control “Register” directive at the top of the page:

<%@ Register TagPrefix="Test" TagName="WPZone" Src="~SiteCollection/_catalogs/masterpage/wpzone.ascx" %>

Note the value of the “Src” attribute – you can use the handy “~SiteCollection” URL token here instead of having to hard-code the server relative URL of the containing site collection. And then the declaration of the user control’s tag inside the markup of the page:

<Test:WPZone runat="server" WPZoneID="TopZone"/>

This simple user control modifies the default rendering of the WebPartZone control whose ID is specified in its “WPZoneiD” property. When the page is in display mode the control hides the web part zone and renders only the web parts that belong to this web part zone. This effectively hides the markup that is produces by the web part zone (several nested HTML table elements) and also the chrome (or frame) headers of the web parts. You should place the control just before the declaration of the web part zone control whose rendering you want to modify.

It is also possible to use user controls just as regular classes with helper methods that can be reused in various places – in this case the user control will not have visual behavior. For example you can create a user control like this (mylib.ascx):

<%@ Assembly Name="Microsoft.SharePoint, Version=,Culture=neutral,PublicKeyToken=71e9bce111e9429c" %>
<%@ Assembly Name="Microsoft.SharePoint.Publishing, Version=, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Control Language="C#" ClassName="MyLib" %>
<script runat="server">
 public static string SayHello(string who)
  return "Hello " + who;
 public string SayHi (string who)
  return "Hi " + who;

Note the “ClassName” attribute in the “Control” directive – this specifies the name of the class that will be generated from the ascx file. You will be able to use this generated class by this name in the code blocks of the pages that use the control (or in other user controls). To use the user control in this way you will only have to put the control “Register” directive at the top of the page. And then in a code block you can have something like:

<script runat="server">
protected override void OnLoad(EventArgs args)
 this.txtBox.Text = MyLib.SayHello("John");

Sunday, September 11, 2011

SharePoint 2010–activate features with feature properties

There are two ways to achieve this in SharePoint – specify the feature properties in the ONET.XML file of your site definition or web template (the new SharePoint 2010 feature) or put the properties directly in the FEATURE.XML definition file of the feature. The latter is almost useless since it almost defeats the purpose of having the type of parameterization that you can achieve with feature properties – which is a very simple and powerful concept – use one and the same feature which can act differently in different contexts. As for the ONET.XML usage of feature properties – I think that this is probably the only thing that justifies the usage of site templates at least for me. In this sense site definitions are not merely a set or a grouping of features that should be activated to a site, provisioning some SharePoint artifacts, but rather a grouping of specifically configured features with this configurability being possible with the usage of feature properties. So despite the numerous issues that one may encounter with site definitions in SharePoint especially when it comes to updating the definition in existing sites, site definitions still have this important and pretty useful bit to offer.

The next question is can this same thing be achieved programmatically. In the SharePoint object model we have the SPFeatureCollection.Add method which allows you to activate features to a site collection or a site. It actually comes with three overloads but none of them allows you to provide specific feature properties that should be used for the feature activation. Of course if you are the “hacker” type of developer and use frequently the .NET Reflector utility you will probably already know that there is an internal method in the aforementioned SPFeatureCollection class that actually accepts a parameter in which you can specify the feature properties for activation. If you Google this you will find that there are actually several blog articles describing this technique. There is one big problem with reflection though – apart from the fact that it is not one of the best practices to use, there is always the risk to get things broken with the next service pack or version of SharePoint. In fact the notation of this exact method changed in SharePoint 2010 as compared to SharePoint 2007.

But is reflection the only option that we have here? It turns out that there is one other way to get this working and you can get an idea of how this is possible again by using the .NET Reflector tool (quite popular for SharePoint development actually). If you use the “analyze” command for the SPFeatureCollection.AddInternal method (the internal method, that I mentioned above) in the .NET Reflector you will see that it is used directly by an internal class called FeatureSerializer from the Microsoft.SharePoint.Deployment namespace. The latter is a namespace in the core Microsoft.SharePoint.dll which contains the SharePoint Deployment API and this is an important clue. If you have done export and import operations for SharePoint site collections or sites you’ve probably noticed that the imported site collections and sites are pretty much exact replicas of the source site collections and sites and that they contain all features with exactly the same feature properties activated as their source counterparts. It is obvious that the deployment API handles not only SharePoint artifacts like SharePoint lists and list items but for sites and site collections the associated features as well. This is where the SPFeatureCollection.AddInternal internal method comes into play invoked by the deployment API.

So, we know that if you have an export package of a site or a site collection (created with the STSADM utility or PowerShell) it will activate the very same set of features in a target site or site collection (or will create them if they don’t exist) but it will also import a ton of other things like all SharePoint lists and list items in them. We face two questions here – one is – is it possible to create an export package that can activate only features to a target site or site collection and the second is – is it legal and allowed by SharePoint standards to create Deployment API packages manually, i.e. without using the Deployment API itself. Starting with the second – this is perfectly OK, the schema of the XML files in a SharePoint deployment package is described officially in MSDN - – the idea is that it can be used by third party providers who want to import content in SharePoint. If you check the article in MSDN you will see that there are eight deployment schema files that a deployment package should contain (although not all of them are actually required). For all deployment schema files there are XSD files which you can find in the 14/TEMPLATE/XML folder (all starting with “Deployment”) and which you can use to validate the XML of the deployment schema files that you create.

And to answer the first question – this can be achieved by creating three small deployment schema files that look like this:


<ExportSettings xmlns:xsi="" xmlns:xsd="" SiteUrl="http://mysite/sites/2" FileLocation="" BaseFileName="" IncludeSecurity="None" IncludeVersions="LastMajor" ExportPublicSchema="true" ExportFrontEndFileStreams="true" ExportMethod="ExportAll" ExcludeDependencies="false" xmlns="urn:deployment-exportsettings-schema">
    <DeploymentObject Id="ea0d5873-cf3a-4015-b015-db74f39db27a" Type="Web" ParentId="00000000-0000-0000-0000-000000000000" Url="" ExcludeChildren="false" IncludeDescendants="None" />


<SystemData xmlns="urn:deployment-systemdata-schema">
  <SchemaVersion Version="" Build="14.0.4762.1000" DatabaseVersion="3683" SiteVersion="0" ObjectsProcessed="1" />
    <ManifestFile Name="Manifest.xml" />
  <RootWebOnlyLists />


<SPObjects xmlns="urn:deployment-manifest-schema">
  <SPObject Id="04a18cb4-39d8-4371-8a21-d11f2b54a333" ObjectType="SPFeature" ParentId="" ParentWebId="" xmlns="urn:deployment-manifest-schema">
    <Feature Id="04a18cb4-39d8-4371-8a21-d11f2b54a333" FeatureDefinitionName="WTSample_SiteScopedFeature" Version="" IsUserSolutionFeature="false" Properties="&lt;Properties&gt;&#xD;&#xA;  &lt;Property Key=&quot;a&quot; Value=&quot;b&quot; /&gt;&#xD;&#xA;&lt;/Properties&gt;" />
  <SPObject Id="4edea5b8-7da5-46cc-b1c6-7a8ce4bcb899" ObjectType="SPFeature" ParentId="" ParentWebId="ea0d5873-cf3a-4015-b015-db74f39db27a" xmlns="urn:deployment-manifest-schema">
    <Feature Id="4edea5b8-7da5-46cc-b1c6-7a8ce4bcb899" FeatureDefinitionName="WTSample_WTMarkFeature" Version="" IsUserSolutionFeature="false" WebId="ea0d5873-cf3a-4015-b015-db74f39db27a" Properties="&lt;Properties&gt;&#xD;&#xA;  &lt;Property Key=&quot;c&quot; Value=&quot;d&quot; /&gt;&#xD;&#xA;&lt;/Properties&gt;" />

You see that the important bits are in the “manifest.xml” schema file – you can see two “SPObject” elements in it with one “Feature” element directly beneath each – these correspond to two features – one “Site” and one “Web” scoped. Have a look at the “Properties” attribute of the “Feature” element – you can see there a familiarly looking “Properties” XML fragment, exactly the same as you have in a standard feature.xml file.

After you have these three schema deployment files you can simply place them in a disc folder and use the deployment API with the SPImport.Run method to import the package as any normal deployment package (note that you will have an uncompressed package as opposed to the compressed packages that STSADM and PowerShell normally output).

An important note here – you can activate only features that are not already activated on the target site or site collection in this manner. If the features are already activated they won’t get reactivated as you can do with the STSADM utility or PowerShell using the “-force” parameter.

If you want to use this approach, instead of formatting the deployment schema files yourselves you can use a handy helper method that I created which nicely wraps the whole logic of the deployment package creation and the running of the SPImort.Run method. You can download the sample solution containing this method from here.

You can also see the source code of the helper method here (it uses some additional private helpers and helper classes whose definitions you can see in the full source code from the above link):

        // provide the target SPWeb and one or several FeatureInfo instances each containing a SPFeatureDefinition and Dictionary<string, string> (for the feature properties) pair

        // you can provide features with Site and Web scopes, Site scoped features are valid only for a root SPWeb

        public void EnableFeature(SPWeb web, params FeatureInfo[] infos)


            // check for valid feature scopes

            bool valid = infos.All(info => info.FeatureDefinition.Scope == SPFeatureScope.Web || (info.FeatureDefinition.Scope == SPFeatureScope.Site && web.IsRootWeb));

            if (!valid) throw new ArgumentException("Invalid feature scope.");


            // load the template SystemData.xml, ExportSettings.xml, Manifest.xml files which are stored as embedded resources

            XDocument systemDataDoc = XDocument.Parse(this.GetManifestResource("WTSample.Core.Xml.SystemData.xml"));

            XDocument exportSettingsDoc = XDocument.Parse(this.GetManifestResource("WTSample.Core.Xml.ExportSettings.xml"));

            XDocument manifestDoc = XDocument.Parse(this.GetManifestResource("WTSample.Core.Xml.Manifest.xml"));


            XNamespace ns = systemDataDoc.Root.Name.Namespace;

            XElement schemaVersionElement = systemDataDoc.Root.Element(ns + "SchemaVersion");

            // set the Build and DatabaseVersion attributes in the SystemData.xml

            schemaVersionElement.SetAttributeValue("Build", SPFarm.Local.BuildVersion.ToString());

            schemaVersionElement.SetAttributeValue("DatabaseVersion", web.Site.ContentDatabase.Version.ToString(CultureInfo.InvariantCulture));


            ns = exportSettingsDoc.Root.Name.Namespace;

            IXmlNamespaceResolver resolver = exportSettingsDoc.Root.CreateNavigator();

            // set the SiteUrl and Id attributes in the ExportSettings.xml

            exportSettingsDoc.Root.SetAttributeValue("SiteUrl", web.Url);

            XElement deploymentObject = exportSettingsDoc.Root.Descendants(ns + "DeploymentObject").FirstOrDefault();

            if (deploymentObject != null) deploymentObject.SetAttributeValue("Id", web.ID);


            ns = manifestDoc.Root.Name.Namespace;

            // extract the existing SPObject element from the Manifest.xml - we will use it as a template for adding the feature SPObject nodes

            XElement featureElement = manifestDoc.Root.Elements(ns + "SPObject").First();

            string featureElementStr = featureElement.ToString();



            foreach (FeatureInfo info in infos)


                // create a new feature SPObject element for every feature definition

                featureElement = XElement.Parse(featureElementStr);



                // set its Id and ParentWebId (the latter only for Web scoped features)

                featureElement.SetAttributeValue("Id", info.FeatureDefinition.Id.ToString());

                if (info.FeatureDefinition.Scope == SPFeatureScope.Web) featureElement.SetAttributeValue("ParentWebId", web.ID.ToString());


                // get the feature's name and the feature's parent solution type

                bool isUserSolution = false;

                string rootDirectory = info.FeatureDefinition.RootDirectory;

                int startIndex = rootDirectory.LastIndexOf(@"\") + 1;

                if (startIndex >= 0) { rootDirectory = rootDirectory.Substring(startIndex); }

                if (rootDirectory.Length == 0)


                    isUserSolution = true;

                    rootDirectory = info.FeatureDefinition.GetTitle(CultureInfo.InvariantCulture) ?? "";



                // create the child Feature element

                XElement contentElement = featureElement.Element(ns + "Feature");

                // set its Id, FeatureDefinitionName, Version, IsUserSolutionFeature and WebId attributes

                contentElement.SetAttributeValue("Id", info.FeatureDefinition.Id.ToString());

                contentElement.SetAttributeValue("FeatureDefinitionName", rootDirectory);

                contentElement.SetAttributeValue("Version", info.FeatureDefinition.Version.ToString(4));

                contentElement.SetAttributeValue("IsUserSolutionFeature", isUserSolution.ToString().ToLower());

                if (info.FeatureDefinition.Scope == SPFeatureScope.Web) contentElement.SetAttributeValue("WebId", web.ID.ToString());

                if (info.Properties != null && info.Properties.Count > 0)


                    // create Properties XML fragment

                    XElement propertiesElement = new XElement("Properties", info.Properties.Select(kv => new XElement("Property", new XAttribute("Key", kv.Key), new XAttribute("Value", kv.Value))));

                    // and assign its value to the Properties attribute

                    contentElement.SetAttributeValue("Properties", propertiesElement.ToString());



                if (string.IsNullOrEmpty(contentElement.Attribute("WebId").Value)) contentElement.Attribute("WebId").Remove();

                if (string.IsNullOrEmpty(contentElement.Attribute("Properties").Value)) contentElement.Attribute("Properties").Remove();


            // create a temporary folder to store the export schema files

            string tempFolder = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());




                // create the export schema files

                systemDataDoc.Save(Path.Combine(tempFolder, "SystemData.xml"));

                exportSettingsDoc.Save(Path.Combine(tempFolder, "ExportSettings.xml"));

                manifestDoc.Save(Path.Combine(tempFolder, "Manifest.xml"));

                // set up the SPImportSettings for the created export batch

                SPImportSettings importSettings = new SPImportSettings()


                    FileCompression = false,

                    FileLocation = tempFolder,

                    SiteUrl = web.Site.Url,

                    WebUrl = web.Url


                // run the SPImport.Run methods to import the batch

                SPImport import = new SPImport(importSettings);






                // clean up - delete the temporary folder

                try { Directory.Delete(tempFolder, true); }

                catch { }



The code contains pretty verbose comments, so that you can easily see how the three deployment schema XML files are formatted and how the input bits from the target SPWeb instance and the feature or features to be activated are fitted in XML elements or attributes inside them. The method accepts a SPWeb input parameter but you can use it for activating “Site” scoped features as well, as long as the SPWeb instance represents the root site of the target site collection.

One last thing to mention – this approach (at least its implementation) may seem a bit complicated and overly verbose as opposed to the one-liner solution when you use reflection. Another thing is that the deployment schema files can hardly be seen as a sort of a contract and we cannot expect that their format won’t get changed in the future in some next release of version of SharePoint. Still, one thing that I find important is that the very same approach of constructing manually deployment packages can as well be used to provision other types of SharePoint artifacts that we thought so far are possible only with XML in feature element files which I think can reveal the great potential of the SharePoint deployment API in this field.