Creating a Plug-in 101
Posted October 3rd, 2008 by Michael Scovetta
So you’ve downloaded and installed Yasca, and like the results, but you want it to write your own plugin. This tutorial will show you how easy it is to do.
First, you should understand how Yasca is designed. Yasca is basically a file scanning engine with the ability to run plug-ins that find interesting things in those files and report the results back to the engine for inclusion into the report. Everything that goes into a report comes from a plugin. (Yasca can do nothing without them.)
Yasca comes with a number of plug-ins by default, including FindBugs, PMD, Jlint, and Grep. The first three are external tools that are maintained by others, but included because I think they provide great information. I wrote the Grep plugin to make it easy to create simple rules that only require regular expression matching. In the first part of this tutorial, we’ll create a new Grep plugin to search for something interesting.
Additional parameters are also available, including:
You can also specify multiple grep patterns, which are logically ‘ORed’ during evaluation.
Place the file you created in the plugins directory and start Yasca. The Grep plugin will automatically find all .grep files within the plugins directory and use them.
In our next tutorial, you’ll learn how to write more complex plugins.
Writing a New Grep Plugin
Writing a Grep plug-in requires you to have a few pieces of information (and a few more optional pieces):- the regular expression to search for, and
- the category (single-line description) of the plug-in
category = Social Security Number Found grep = /\d{3}-\d{2}-\d{4}/
- file_type - a comma-separated list of file extensions to apply this plug-in to
- category_link - a URL containing more information about this particular plug-in
- severity - the severity (1=critical down to 5=informative)
- description - a multi-line description of the plug-in, ending with a line containing only the string “END;”
name = Missing AM or PM in Time Format file_type = java,jsp grep = /hh:mm:ss\"/ category = Formatting: Missing AM/PM in Time Format severity = 2 description = <p> When specifying time formatting in Java, the phrase "hh:mm:ss" is based on 12-hour time, so 5:00 AM and 5:00 PM would both be rendered as "05:00:00", possibly confusing the user. Instead, use either "HH:mm:ss", which is based on 24-hour time, or include either AM or PM by using "hh:mm:ss a". </p> <p> <h4>References</h4> <ul> <li>TODO</li> </ul> </p> END;