The easiest way to install a new mode locally is to use the Editing dialog found under Utilities - Global Options. At the bottom of this dialog is an "Add Mode" button. Clicking this button shows a dialog to add a mode to jEdit. Simply fill in the blanks and the mode file will be put in the proper place and the catalog file will be updated appropriately. Modes added this way can be removed by selecting the mode in the Editing dialog, then clicking the "Delete Mode" button. This button will only appear for modes that exist in the user settings directory. Core modes, that is, those modes distributed with jEdit cannot be deleted this way. The details of adding a mode by hand are below.

jEdit looks for edit modes in two locations; the modes subdirectory of the jEdit settings directory, and the modes subdirectory of the jEdit install directory. The location of the settings directory is system-specific; see the section called “The jEdit Settings Directory”.

Each mode directory contains a catalog file. All edit modes contained in that directory must be listed in the catalog, otherwise they will not be available to jEdit.

Catalogs, like modes themselves, are written in XML. They consist of a single MODES tag, with a number of MODE tags inside. Each mode tag associates a mode name with an XML file, and specifies the file name and first line pattern for the mode. A sample mode catalog looks as follows:

<?xml version="1.0"?>
<!DOCTYPE CATALOG SYSTEM "catalog.dtd">

<MODES>
    <MODE NAME="shellscript" FILE="shellscript.xml"
        FILE_NAME_GLOB="*.sh"
        FIRST_LINE_GLOB="#!/*sh*" />
</MODES>

In the above example, a mode named “shellscript” is defined, and is used for files whose names end with .sh, or whose first line starts with “#!/” and contains “sh”.

The MODE tag supports the following attributes:

Glob pattern syntax is described in Appendix D, Glob Patterns.

When a buffer is opened, jEdit must choose an edit mode for that buffer. It checks conditions in this order to decide which edit mode to use: