NewsRog Tutorial 13: Display Filters

Tutorial 13: Display Filters

Contents:	Display Filters	Filter Scope
	Adding & Removing Filters	Editing Filters
	Common Filter Features	Global Filter Data
	Summary

What are Display Filters?

Display filters modify the way in which articles are displayed in the group window's article view area. The original article is not modified in any way, only its presentation is affected. Display filters might do things such as trim excess quoted text, colorize various aspects of an article, hide unwanted header fields, and so on. It's possible to make display filters group specific, or to apply them to any subset of groups, such as "comp.*".

This section of the documentation discusses general display filter topics. The specifics of each different type of filter are covered in the reference section of this documentation.

Filter Scope

Filters can be defined within the context of a particular group, in which case they apply only to that group, or they can be defined globally to apply to groups matching any particular pattern (set in the Group Patt area of the filter list). Global filters are defined in the configuration editor for NewsRog. Group specific filters are defined from within the group reader window. Generally, if a filter is to apply to more than one group (for example, to comp.*) it is best to define it once in the configuration editor instead of duplicating the filter in each group.

Adding and Deleting Filters

In each filter list there is an Add button that, when pressed, will display a popup list of available filters. Filters are plug-ins, so the list may change depending on which filters are currently installed. The popup filter list looks like this:

A filter may be added by double clicking on it's name in the popup list. The list may be closed without adding a filter by clicking the Add button again.

Removing filters is a simple matter of selecting those to be removed and using the Delete button.

Editing Filters

Each filter provides a user interface for customizing its operation. For example, a quoted text hilighting filter might let you chose the font and color for text of different quoted indent levels, while a header hiding filter might let you specify a pattern indicating which headers to hide and which to show.

The user interface for any filter may be called up by either double clicking on the name of the filter in the filter list, or by using the Edit button.

Common Filter Features

Certain information is available in every type of selection filter. Calling up the editor for a particular filter reveals three main click tabs:

Filter Settings - This is where you edit information specific to this particular filter. What appears here will differ depending on the type of filter in question.
Global Info - This area edits data common to all types of filters.

Global Info

The global info area looks like this:

The following features are available here:

The filter description is any short string that will remind you of the purpose of this filter. Filters can be toggled on and off individually to change the presentation of articles in the group, and this name can serve to remind you what a particular filter does.
The Enable checkbox toggles this filter on or off. Filters that are not enabled have no effect on the displayed article presentation.

The filte description may also be changed by typing into the name box in a filter list when a particular filter is selected. The Enabled option may be toggled on and off from the filter list by clicking in the appropriate column of the list. Back to Top

Summary

By this point in the tutorial you should understand:

What display filters are.
That display filters change only the presentation of articles, not the article itself.
What filter scope refers to, and the difference between global and group specific filters.
How to add and remove filters.
How to edit a particular filter's parameters.
How to change a filter's description.
How to enable and disable filters.