Using advanced C# features in Sharepoint development

USING OF ADVANCED C# FEATURES IN SHAREPOINT

DEVELOPMENT

Alexey Sadomov, PhD, Sharepoint MVPhttp://sadomovalex.blogspot.com/

Episode 1. Application _layouts pages with embedded server code

Efficient way to troubleshoot issues, which are not reproduced on dev environment

Page is opened in context of living site, e.g. http://example.com/_layouts/test.aspx

Do not require updates of wsp packages Do not require installations of dlls into the GAC Can be easily removed from production after

troubleshooting without leaving security holes C# 2.0 is available by default for server scripts

Episode 1. Application _layouts pages with embedded server code

Example: trace info about thread principal and currently logged Sharepoint user

Episode 1. Application _layouts pages with embedded server code

Example: trace info about thread principal and currently logged Sharepoint user

Episode 1. Application _layouts pages with embedded server code

Enable features of C# 3.0 in _layouts pages via web.config:

All features of C# 3.0 become available (e.g. lambdas, query expressions, etc.): see Overview of C# 3.0

Episode 1. Application _layouts pages with embedded server code

Sharepoint 2013 preview: Web sites are created with .Net 4.0 app pools Default compiler is set to version 4.0 It is possible to use features of C# 4 (e.g. dynamic

types) in embedded server scripts without additional configurations

Episode 2. Reflection: the last defense line

Use when can’t solve problem with standard tools

Requires preliminary investigation of Sharepoint code: JetBrains dotPeek Telerik JustCompile Reflector

Where to search Sharepoint dlls: GAC 14/ISAPI inetpub\...\mywebapp\_app_bin

Episode 2. Reflection: the last defense line

Real life example: Create instance of SPSite in

SPSecurity.RunWithElevatedPrivileges() method Open SPWeb Code is executed under SHAREPOINT\System account (app

pool identity) Call standard API which in turns uses

SPContext.Current.Site or SPContext.Current.Web Result: access denied page

Episode 2. Reflection: the last defense line

Analyzing code of SPContext:

Episode 2. Reflection: the last defense line

Analyzing code of SPContext:

Episode 2. Reflection: the last defense line

Use knowledge of Sharepoint code and reflection for solving the problem:

Episode 2. Reflection: the last defense line

ReflectionHelper code:

Episode 3. Dynamic methods: the dark side

Can be used for generating and executing a method at run time, without having to generate a dynamic assembly and a dynamic type to contain the method

The executable code created by the just-in-time (JIT) compiler is reclaimed when the DynamicMethod object is reclaimed

If the dynamic method is associated with specific type, it has access to all members of the type, regardless of access level

Dynamic methods and their parameters do not have to be named

Allows to avoid some limitations of C#: e.g. although dynamic methods are static methods the relaxed rules for delegate binding allow a dynamic method to be bound to an object, so that it acts like an instance method when called using that delegate instance

Episode 3. Dynamic methods: the dark side

Example: dynamic method for calculating factorial

Episode 3. Dynamic methods: the dark side

How it can be used in Sharepoint? Example: use Telerik RadEditor in all sub sites in web

application without feature activations RadEditorFeature – overrides rendering template for RichTextField

with Telerik control RadEditorFeatureIE – “flag” feature, depends on RadEditorFeature

Technically it is enough to activate RadEditorFeature once For new sites:

Activate features manually Use feature stappling for OTB site definitions Modify onet.xml file for custom site definitions

Episode 3. Dynamic methods: the dark side

Where problem is coming from? RadHtmlListField class:

Episode 3. Dynamic methods: the dark side

Solution: Define new class inheritor of RadHtmlListField Define OnLoad() by the same way as in RadHtmlListField using reflection Always return true from ShowEditorOnPage() method

Inheritance chain: AllBrowsersHtmlListField –> RadHtmlListField –> MOSSRadEditor

The problem: how to call MOSSRadEditor.OnLoad() from AllBrowsersHtmlListField.OnLoad() without caling RadHtmlListField .OnLoad()? I.e. we need to skip one tier in the inheritance chain and call virtual method

OnLoad(), but not from base class, but from base of base class Answer: no how in standard C# Can dynamic method help here? Yes

Episode 3. Dynamic methods: the dark side

Example: create dynamic method for skipping one tier in virtual members calls

Episode 4. Code generation, expression trees, CAML reverse engineering, Camlex online

Camlex – open source project which simplifies creating of CAML queries for SharePoint by using expression trees

Uses expression trees and lambda expressions for generating CAML Simplifies creation of dynamic CAML queries when conditions are

calculated in runtime Doesn’t require knowledge of CAML from developers Supports native .Net types and Sharepoint-specific types http://camlex.codeplex.com/

Episode 4. Code generation, expression trees, CAML reverse engineering, Camlex online

Example of usage:

Direct translator:

Episode 4. Code generation, expression trees, CAML reverse engineering, Camlex online

Camlex 3.0 Reverse Engineering – creates expression trees based on strings

Reverse Engineering translator:

Episode 4. Code generation, expression trees, CAML reverse engineering, Camlex online

Camlex Re + ExpressionToCode = Camlex Online: http://camlex-online.org/

Simplifies usage of Camlex for developers who didn’t have experience with it yet

Quick refactoring of existing hard-coded CAML queries to Camlex Fully reversible CAML query schema opens many interesting

applications in future Example of combining of several non-trivial OSS projects

Episode 4. Code generation, expression trees, CAML reverse engineering, Camlex online

Add conditions to existing string queries using lambda expressions:

Episode 4. Code generation, expression trees, CAML reverse engineering, Camlex online

Expand ViewFields, GroupBy, OrderBy:

Episode 5. Write C# code in PowerShell

Built-in to OS, doesn’t need VS for writing and running C# programs

May be useful: if you already have a code which want to reuse have existing C# code which is hard to move to PowerShell for developers who know C#, but only started work with PowerShell if you want to run quick test, but don’t want to run VS and compile

dll C# 3.0 can be used: -Language CSharpVersion3 Can specify existing assemblies or source code files

Episode 5. Write C# code in powershell

Example: enumerate sub-sites using C# code in PowerShell

Additional materials http://sadomovalex.blogspot.com/ Use C# 3.0 features in application layout pages in Sharepoint:

http://sadomovalex.blogspot.fi/2010/12/use-c-30-features-in-application-layout.html

Use Telerik Rad Editor Lite without features activation: http://sadomovalex.blogspot.fi/2011/12/use-telerik-rad-editor-lite-without.html

Generating Dynamic Methods with Expression Trees in Visual Studio 2010: http://blogs.msdn.com/b/csharpfaq/archive/2009/09/14/generating-dynamic-methods-with-expression-trees-in-visual-studio-2010.aspx

Camlex project site: http://camlex.codeplex.com/ Camlex online: http://camlex-online.org/ ExpressionToCode: http://code.google.com/p/expressiontocode/ Materials from followings sites are used for presentation:

http://newswallpapers1.blogspot.com, http://arts-wallpapers.com, http://www.fanpop.com, http://wallpaperswide.com, http://starwars.wikia.com