Wednesday, March 01, 2006

Extreme SharePoint Design: Modifying 'Grouped By' Headers, Part 2

Creating a grouped list in SharePoint is easy – just Modify Settings and Columns, Create View, and select the column(s) to group on; however, getting the grouping to sort and display the way you want isn’t quite so simple. By default, SharePoint sorts alphabetically and there aren’t any options to hide group headers, style them individually, or change the layout.

One of the most common requirements for grouped listings is to create a manual sort mechanism to circumvent the built-in alphabetical sort. This is easily done by adding a new field with a numerical value and assigning each list entry to the appropriate identifier. When a new view is created, the list is first grouped by the sort field and next by whatever content field is appropriate. The problem is that the user sees the sort field in the first group header and there’s no way to turn it off in the list settings.

There are two ways to solve this problem. You can modify the SCHEMA.XML file for the list type and change the CAML to render the groupings the way you want them (read this post to learn how). The issue with this method is that it is a global change; all lists of the same type in the site definition will be changed. Alternatively, you can override the default styles using a web part which hides or alters the appearance of the stock group header on a page by page basis.

Each header level is contained within a table row that inherits the ‘ms-gb’ (first group header) or ‘ms-gb2’ (second group header) style from OWS.CSS. To override these styles, add a Content Editor Web Part (CEWP) to the page, open the Source Editor in the tool pane, and add your own stylesheet entry. For example, to hide the first group header row entirely (dark gray bar in default theme), enter the following:


Disable the CEWP’s ‘Display on page’ setting (under ‘Layout’ in the tool pane) to hide the web part, save it and the group header disappears. Because the CEWP is rendered after the default stylesheet references in the site definition page, it overrides the settings in OWS.CSS following the cascading rules of CSS (last reference takes precedence). Technically, the header still exists, users just can’t see it. Use the same method to apply font colors, background images, margins, and any other CSS style properties.

Unfortunately, this method doesn’t work as well for altering the actual text of the header entry (i.e. removing the ‘[Group Name] :’ prefix). You can use JavaScript to achieve this effect by altering the innerHTML property of each header and using the getElementById method, but you’ll have to apply it individually to each header ID and they’re not always the same from page to page. Plus, JavaScript in CEWP’s often causes unpredictable results (such as preventing web parts from being saved or disabling tool bar functions). If you do plan to use JavaScript on a web part page, it’s always best to store the script in a document library as a .js file or as part of an HTML page then call that page using a Page Viewer Web Part.