Comments on: Custom Lookup Fields http://chrisforbesblogs.net/2009/03/15/custom-lookup-fields/ Developers chat on SharePoint and .NET Tue, 29 Jun 2010 13:51:55 +0000 hourly 1 http://wordpress.com/ By: pholpar http://chrisforbesblogs.net/2009/03/15/custom-lookup-fields/#comment-77 pholpar Thu, 28 Jan 2010 08:47:13 +0000 http://chrisforbesblogs.wordpress.com/2009/03/15/custom-lookup-fields/#comment-77 You can read a workaround for this issue here (see comment from Alex Hekstra): WSS 3.0 SPField derrived classes http://willemboere.blogspot.com/2007/04/wss-30-spfield-derrived-classes.html The trick from Alex worked me too, thanks for that, but here is the official hotfix for the issue: Description of the Windows SharePoint Services 3.0 Cumulative Update Server hotfix package (Sts-x-none.msp): December 15, 2009 http://support.microsoft.com/default.aspx/kb/977022/ "You develop a custom field type that inherits from the SPFieldLookUp class. You want to store multiple values in a field of that custom field type. Therefore, you set the AllowMultipleValues property to True. However, after you set the AllowMultipleValues property to True, the field type is displayed as Lookup instead of the custom field type." Hope that helps. Peter You can read a workaround for this issue here (see comment from Alex Hekstra):

WSS 3.0 SPField derrived classes
http://willemboere.blogspot.com/2007/04/wss-30-spfield-derrived-classes.html

The trick from Alex worked me too, thanks for that, but here is the official hotfix for the issue:

Description of the Windows SharePoint Services 3.0 Cumulative Update Server hotfix package (Sts-x-none.msp): December 15, 2009
http://support.microsoft.com/default.aspx/kb/977022/

“You develop a custom field type that inherits from the SPFieldLookUp class. You want to store multiple values in a field of that custom field type. Therefore, you set the AllowMultipleValues property to True. However, after you set the AllowMultipleValues property to True, the field type is displayed as Lookup instead of the custom field type.”

Hope that helps.

Peter

]]> By: Stuart Fieldhouse http://chrisforbesblogs.net/2009/03/15/custom-lookup-fields/#comment-70 Stuart Fieldhouse Tue, 10 Nov 2009 09:05:04 +0000 http://chrisforbesblogs.wordpress.com/2009/03/15/custom-lookup-fields/#comment-70 ...the schemaXml I pasted in didn't come through in the message... The schema contains Type, DisplayName, Required, List, ShowField, UnlimitedLengthInDocumentLibrary, ID, SourceID, StaticName, BaseRenderingType (="Lookup"), Name, ColName and RowOrdinal …the schemaXml I pasted in didn’t come through in the message…

The schema contains Type, DisplayName, Required, List, ShowField, UnlimitedLengthInDocumentLibrary, ID, SourceID, StaticName, BaseRenderingType (=”Lookup”), Name, ColName and RowOrdinal

]]> By: Stuart Fieldhouse http://chrisforbesblogs.net/2009/03/15/custom-lookup-fields/#comment-69 Stuart Fieldhouse Tue, 10 Nov 2009 09:01:18 +0000 http://chrisforbesblogs.wordpress.com/2009/03/15/custom-lookup-fields/#comment-69 Thanks for the reply Chris. My field type is deployed via a WSP, so the feature receiver looked like a good route. However, I'm not assigning the type to any site columns - I'm simply trying to create a new user-creatable type which they can assign to a column in any list, just like a standard lookup column. In the receiver, since there is no actual field yet, I am looking at the SPFieldTypeDefinition and the FieldInfo but neither of these contain any schema info. When the user actually creates a column of my type, I intercept the OnAdded, but at that point the schemaXml contains only this: ... no mention of LookupMulti. Any ideas? Thanks for your help, Stuart. Thanks for the reply Chris. My field type is deployed via a WSP, so the feature receiver looked like a good route. However, I’m not assigning the type to any site columns – I’m simply trying to create a new user-creatable type which they can assign to a column in any list, just like a standard lookup column. In the receiver, since there is no actual field yet, I am looking at the SPFieldTypeDefinition and the FieldInfo but neither of these contain any schema info. When the user actually creates a column of my type, I intercept the OnAdded, but at that point the schemaXml contains only this:

… no mention of LookupMulti. Any ideas? Thanks for your help, Stuart.

]]> By: Chris Forbes http://chrisforbesblogs.net/2009/03/15/custom-lookup-fields/#comment-68 Chris Forbes Mon, 09 Nov 2009 21:01:07 +0000 http://chrisforbesblogs.wordpress.com/2009/03/15/custom-lookup-fields/#comment-68 Hi Stuart, Well in my case I added this to a feature receiver which was stapled to a site def. When a user clicked a button I had a new sub site created which then created a bunch of libraries and lists etc. It was at this point that the feature receiver code got a handle on the look up fields and modified the SchemaXML. This approach is probably not appropriate for your scenario? Let me know who you intend using the field and I'll have a think Chris Hi Stuart,

Well in my case I added this to a feature receiver which was stapled to a site def. When a user clicked a button I had a new sub site created which then created a bunch of libraries and lists etc. It was at this point that the feature receiver code got a handle on the look up fields and modified the SchemaXML.

This approach is probably not appropriate for your scenario? Let me know who you intend using the field and I’ll have a think

Chris

]]> By: Stuart Fieldhouse http://chrisforbesblogs.net/2009/03/15/custom-lookup-fields/#comment-67 Stuart Fieldhouse Mon, 09 Nov 2009 18:03:25 +0000 http://chrisforbesblogs.wordpress.com/2009/03/15/custom-lookup-fields/#comment-67 Chris, could you please tell me at what point you are changing the SchemaXml to get over the LookupMulti problem? I tried putting it into the OnAdded override in the field class, but to no avail. Many thanks, Stuart. Chris, could you please tell me at what point you are changing the SchemaXml to get over the LookupMulti problem? I tried putting it into the OnAdded override in the field class, but to no avail. Many thanks, Stuart.

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