Category / Sharepoint 2010

by Simon Doy

Creating List Instance: Object Reference not set to an instance of an object


Introduction

This one is a bit of an old issue but some of my posts are just to remind me of a time that I got stuck in the past. Also if it helps someone else then great.

It is possible to create a feature which creates an instance of a SharePoint List when its activated. However, sometimes you only want a list to be created on the Root Web of a site collection.

Issue

Well the XML for specifying a ListInstance as a feature has an attribute called RootWebOnly which I thought I could use to only allow the ListInstance to be created on the RootWeb.

Unfortunately when you do that you get a message like the following in your SharePoint ULS Logs when the feature is activated:-

Feature Activation: Threw an exception, attempting to roll back. Feature ‘FeatureName’(ID: ‘xxxxxxxx-xxxx-xxxx-xxxxxxxx). Exception: System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.SharePoint.SPListInstanceElement.ElementActivated(SPFeaturePropertyCollection props, SPSqlCommand sqlcmdAppendOnly, SPWebApplication webApp, SPSite site, SPWeb web, Boolean fForce)
at Microsoft.SharePoint.Administration.SPElementDefinitionCollection.ProvisionListInstances(SPFeaturePropertyCollection props, SPSite site, SPWeb web, Boolean fForce)
at Microsoft.SharePoint.Administration.SPElementDefinitionCollection.ProvisionElements(SPFeaturePropertyCollection props, SPWebApplication webapp, SPSite site, SPWeb web, Boolean fForce)
at Microsoft.SharePoint.SPFeature.ProvisionElements(SPFeaturePropertyCollection props, SPWebApplication webapp, SPSite site, SPWeb web, Boolean fForce)
at Microsoft.SharePoint.SPFeature.Activate(SPSite siteParent, SPWeb webParent, SPFeaturePropertyCollection props, Boolean fForce)

The offending Feature ListInstance element is below:-

 1: <?xmlversion="1.0" encoding="utf-8"?>
 2: <Elements
 3: xmlns="http://schemas.microsoft.com/sharepoint/">
 4: <ListInstance
 5: Id="AListId"
 6: Title="A List"
 7: Description="A List 
 8: Description”
 9: Url="Lists/ListUrlHere"
 10: OnQuickLaunch="FALSE"
 11: RootWebOnly=”TRUE”
 12: FeatureId="xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxx"
 13: TemplateType="45100"></ListInstance>
 14: </Elements>

Solution

To fix the feature activation remove the RootWebOnly=”TRUE” from your ListInstance element manifest file and instead move the RootWebOnly=”TRUE” into your List’s schema.xml.

To ensure that the list is only provisioned at the root web of the site collection change the Feature.xml to use Scope=”Site”

Update:

Thanks to Dennis who picked up my mistake in this post which stated that the RootWebOnly attribute should be moved to the feature.xml.

by Simon Doy

Fix: Content Editor Web Part Rich Text Editor Popup fails to display


 

Introduction

This problem has been bugging me for the past 3 days and so I thought I’d be kind and document it just in case it has been causing someone else problems.

So the issue is with the SharePoint 2007 Content Editor Web Part and when you edit the web part and click the button to show the Rich Text Editor you get a JavaScript error.

There does seem to be another post on MSDN (http://social.msdn.microsoft.com/Forums/en-NZ/sharepointcustomization/thread/90e14ff3-7003-44fd-9b4c-d9e654f7d8e1 that was showing the same issue and although the fix was related, the fixes that were specified in this post didn’t help me.

 

Issue

So as I have already mentioned when using the SharePoint 2007 Content Editor Web Part’s Rich Text Editor Dialog you get the following JavaScript error:-

Invalid Argument in HtmlEditor.js at line 5740, character position 2

On further investigation it is this line in the HtmlEditor.js file that is causing the problem.

elem=document.getElementByid(containerId);

Actually if you follow the JavaScript code then the issue seems to be down to the piece of JavaScript where the web parts are registered on the page. At the bottom of each SharePoint page is a section of JavaScript that looks something like this:-

 1: <script LANGUAGE='Javascript'>


  

 2: <!--


  

 3: WPSC.Init(document);


  

 4: var varPartWPQ1 = WPSC.WebPartPage.Parts.Register('WPQ1','[GUID]',document.all.item('WebPartWPQ1'));


  

 5: WPSC.WebPartPage.WebURL = 'http:\u002f\u002fsharepointurl';


  

 6: WPSC.WebPartPage.WebServerRelativeURL = '\u002f';


  

 7: //-->


  

 8: </script>

It seems that the JavaScript which creates the varPartWPQ1 variable does not work properly as the varPartWPQ1 is created without populating its ID property. This ID property is the value that is assigned to containerId in the line:-

elem=document.getElementByid(containerId);

 

The Solution

After a lot of trial and error I found that it was to do with the master page and a <meta> tag within the master page’s <head> tag.

The tag causing the problem is this one:-

 1: <meta http-equiv="X-UA-Compatible" content="IE=8" />

Removing this line and redeploying the master page fixed the JavaScript error.

This meta tag tells IE to run in IE 8 Standards mode which seems to cause a problem with the browser when its trying to get a document item using the function document.all.item([itemid]).

For more information on the <meta> tag please see the following article on Defining Document Compatability (http://msdn.microsoft.com/en-us/library/cc288325(VS.85).aspx)

 

Further Information

The reason for this happening was actually that the master page was being ported back from a SharePoint 2010 master page to a SharePoint 2007 master page.

This tag was left in from the SharePoint 2010 master page.

I really do hope this helps someone as it drove me mad for a while.