Display Custom Field in a Content Query Web Part

Today I struggled with a problem when trying to display a custom field into my CQWP. I tried to display a custom field whose internal field consist of two parts. eg. News Date.

When I filled in the internal field name this way:
<.property name="CommonViewFields" type="string".>News Date,Text;<./property.>" the field didn't render.

Solution
<.property name="CommonViewFields" type="string".>News_x0020_Date,Text;<./property.>"

The characters _x0020_ represent the blank space.

Retrieve List Guids, Internal Field Names & ContentTypeIDs

When you are in want of some Guids, Internal Fieldnames or ContenttypeIDs during the development... you don't have to look that far. I just realized that the info is available in the URL.

So when you need a List Guid, just navigate to the list settings page and copy the Guid after the "List=" string. Be aware of that the GUID is URL encoded. For that reason you have to decode the Guid or just remove the special characters and add braces.

For a ContenttypeID, navigate to the contenttype in the site contenttype gallery and copy the ID after the "ctype=" string out of the URL.

For an internal Fieldname, navigate to the site column page for a particular column and copy the fieldname after the "field=" string out of the URL.

Automatically activate a Site/Web Scoped Feature

I'm wondering if there is a way to automatically activate Site or Web scoped features after the feature installation. I did some research and found a XML attibute "ActivateOnDefault", which you can place in the feature definition file (feature.xml).

I placed the attribute into the feature.xml to force the feature to activate himself after installing, with no results...

Reason:
The ActivateOnDefault attribute does not apply to site collection (Site) or Web site (Web) scoped Features.

In general, Farm-scoped Features become activated during installation, and when a new Web application is created, all installed Web application-scoped Features in it become activated.

So I think the only way to accomplish this is to write some code within the "FeatureInstalled" method of the FeatureEventHandler: Activate features through code.

Problem with deleting a solution

For once I got an error when trying to remove an existing SharePoint Solution (.wsp) from the SharePoint Server.

The solution cannot be removed when a job is scheduled or running

Also when you go to the Central Administration > Operations > Solution Management, you will notice that an error shows up in the list of solutions.

Off course there is a way to fix this. Alex Thissens wrote a nice blogpost of this issue. Maybe there are other ways to fix this, but Alex' way worked for me.