This tutorial shows you how you can create a tag library for your own needs. It makes sense to add a custom library if some functionality recurs in your project(s). We will create a simple tag library ("font") with a tag with the ability to format text as bold (bold).

Setting up

Every tag library needs a unique namespace (like xeb or page). We create a folder in $FONT_TAG_LIBRARY where we put all our configuration and tag library files. The API of our tag library is defined in a file called config.taglib and has to be located in $FONT_TAG_LIBRARY. Since we don't have any tags yet, the file will just contain a skeleton:

<taglib id="font">
</taglib>

With this configuration we created a tag library with the namespace "font" and no tags. Since tag libraries are used as libraries we need to add a font_tag_library.ecf in the same folder as well:

<?xml version="1.0" encoding="ISO-8859-1"?>
<system xmlns="http://www.eiffel.com/developers/xml/configuration-1-5-0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.eiffel.com/developers/xml/configuration-1-5-0 http://www.eiffel.com/developers/xml/configuration-1-5-0.xsd" name="font_tag_library" uuid="491B4344-79AF-43CB-891B-47EDEAC11056" library_target="font_tag_library">
	<target name="font_tag_library">
		<root all_classes="true"/>
		<option full_class_checking="true" syntax="transitional">
			<assertions precondition="true" postcondition="true" check="true" invariant="true" loop="true" supplier_precondition="true"/>
		</option>
		<library name="base" location="$ISE_LIBRARY\library\base\base.ecf"/>
		<library name="xebra_ast_elements" location="$XEBRA_DEV\eiffel_projects\library\xebra_ast_elements\xebra_ast_elements-voidunsafe.ecf"/>
		<library name="xebra_tags" location="$XEBRA_DEV\eiffel_projects\library\xebra_tags\xebra_tags-voidunsafe.ecf"/>
		<library name="xebra_utilities" location="$XEBRA_DEV\eiffel_projects\library\xebra_utilities\xebra_utilities-voidunsafe.ecf"/>
		<cluster name="font_tag_library" location=".\" recursive="true">
			<file_rule>
				<exclude>/EIFGENs$</exclude>
				<exclude>/.svn$</exclude>
				<exclude>/CVS$</exclude>
			</file_rule>
		</cluster>
	</target>
</system>

Adding Tags