SharePoint 2010: Create a Content Type with Lookup Field by writing declarative XML

Create a content type with a lookup field in the Elements.xml file is not easy how you can think.

To accomplish this task you need to:

• define the new field
• specify Name, DisplayName, StaticName
• set at TRUE the Overwrite attribute
• set at ~sitecollection the WebId attribute
• set at TheLookupList the List attribute
• set at http://schemas.microsoft.com/sharepoint/v3 the SourceID attribute

for example:

<!-- CT Sotto Reparto -->
<Field ID="{2AAD1044-89E9-4C88-8234-424A4B739C1C}" Name="LookupToList" DisplayName="LookupToList" StaticName="LookupToList"
       Type ="Lookup"
       Required="TRUE"
       Group="Custom Columns"
       Overwrite="TRUE"
       WebId="~sitecollection"
       EnforceUniqueValues="FALSE"
       List="Lists/MyList"
       SourceID="http://schemas.microsoft.com/sharepoint/v3"
       ShowField="MyLookupField" />

bye!