I few months ago I posted on RenderPatterns and how they are used when creating custom fields for SharePoint. In that post the point I was trying to make was that when viewing data in a list nothing else matters except the render pattern. None of your highfalutin C# SPField derived classes can save you from the madness that is the render pattern. Never mind what MSDN says about using an .ascx control - there is no other way. So with that said, given that we’re stuck with the render pattern, it would be good to know a bit...

When you upload images to a SharePoint picture library three images are actually stored. Firstly there's the actual image that you uploaded then there are two others with specific sizes. There’s a thumbnail image that’s scaled to a particular width and is used in the default ‘All Pictures’ view then there’s a web image that’s resized to a specific width and height. The thumbnails are saved to a hidden folder in the picture library named _t and the web images are saves to a hidden folder named _w. Let’s say you have a few web parts that make use...

Ever tried to add a custom field control to a Custom List Form in SharePoint Designer? You’d think it’d be simple, just drag the field from the toolbox and stick it on the form. Nah! We haven’t heard much from Ernő Rubik in recent years. I’m convinced he’s at Microsoft working on the SharePoint team (and doing a bit of work in the WF team when he’s got a chance) You’ll come across a few problems when trying to add your custom field control (or any other type of custom control) to a custom list form. As you may...

The source code for this article is available on CodePlex Introduction If you’ve been developing applications for SharePoint for any length of time you’ll undoubtedly have come into contact with the security model. Based on the asp.net provider model, SharePoint itself does not authenticate users, it merely provides authorisation. That is to say that SharePoint does not verify that users are who they claim to be, it simply makes use of the users identity to determine what resources should be available to the user. Of course this does not mean that user identities are not verified, just that...

December’s looking a bit bare on my blog calendar. I thought I’d better add something before the festivities begin. In truth I’ve been pretty busy over the past few weeks. I spent a few days doing an excellent CTT+ course at Rezound in Sheffield plus I’ve also just started work on a new SharePoint 2010 book for McGraw-Hill. That’s not to mention my outstanding commitment to Wrox to deliver a short e-book on SharePoint 2007 Packaging and Deployment, my ongoing development work and the joys of having two children, one of which hasn’t quite grasped the concept of sleeping yet!...

A few weeks ago I promised to post a few articles about extending CAML to deal with some of the elements that you’d normally have to write code in order to package. To be honest I’ve been putting it off in the hope that SharePoint 2010 and VisualStudio 2010 would make all these problems go away but it seems that that isn’t going to happen, at least not completely. So no more excuses, I may as well get on with it! I wanted to cover Lookup fields in this post. Somebody recently asked about this on the forums and...

Have you ever thought “it would be really cool if I could create a field control for my publishing page that would interact with all the other field controls"? I’ll bet you have, I know you don’t want to admit it because the idea is madness but I’ll bet you have! (No? I guess I’m out on my own with that one then?) I’ve only really gotten into the latest version of Silverlight in the past few weeks and I have to say I’m impressed. The potential for integration with SharePoint is huge and that’s before we consider the...

I’ve been following a few forum posts about modifying the built-in navigation providers in SharePoint and thought I’d knock up a quick post explaining, step-by-step how this can be done. Unfortunately, the documentation at MSDN is a bit cryptic (Although you’ll see by the end of this article that it makes perfect sense!) As usual, I won’t get into details about creating and deploying features. WSPBuilder is your man. (Although I’m finding SPVisualDev to be a handy wee tool as well these days) So what’s the plan then? On the default master page, you’ll see code...

I thought I’d have a read through the technical preview docs for SP2010 and came up against this problem: I’ve seen this problem a few times before when tying to access .CHM files. It often happens when you download SDK documentation from the web. (Unsurprisingly since it’s a security feature designed to prevent downloaded content from causing mayhem on your PC!) To fix it: Find the file that you’re trying to view, in my case: SPPT2010TP.CHM Right click then select Properties: Hit the Unblock button...

Ever wanted to be read the Status text displayed on WrkStat.aspx programmatically so that you can make use of it elsewhere? No? Can’t blame you! However, let’s say that you do fancy a bit of masochism. Here’s how it works: The status value is stored in a field of type SPFieldWorkflowStatus. Generally this field has the same display name as your workflow although it’s internal name will be different. Getting the internal name is a pain, for some bizarre reason Microsoft decided to expose this as an internal property rather than public. (See SPWorkflowAssociation.InternalNameStatusField). After...