User Guide

Building Tag Editors 177

Populating dialog boxes with tag data

Once the layout of controls is completed, you need to define the way in which the

editor controls are populated when you are editing an existing tag. This is done in the

attributes block of the main tag editor template.

The

attributes block can contain attrib and event tags. The attrib tag defines

the way in which tag attribute values are inserted into the dialog controls.

</attributes>

The name attribute of the attrib tag specifies the name of the attribute, while

control specifies which control the value of that attribute should be assigned to. You

can have multiple

attrib tags with the same name. This is common for more

complex tag editor dialog boxes where a single attribute value may have to be filled

into multiple controls.

Special attrib tag variable names

The following special variables can be used:

• $$TAGBODY This special tag attribute name is used when a control needs to

be populated by the body of a tag. An example of such a tag editor is the editor for

the HTML tag

textarea. The body of the textarea tag is filled into the

txtTextAreaContent control using the following attrib code:

• $$TAGSTRING and $$WHOLETAGSTRING These attributes can be used to

populate controls with the start tag string or the whole tag including its start tag,

body and the end tag. This allows ActiveX controls to be passed to the entire tag

for custom processing and specialized tag editor behavior.

• $$EmbeddedCodeString Represents just the text within a tag. It excludes the

tag name, delimiters, and white space outside the text block.

Generating a tag

The final stage in the process of building a tag editor is defining how a tag gets

generated from the date entered in the editor controls. The tag generation logic is

stored in the

taglayout block. This block contains a short template used to generate

the final tag string.

A good way to get started is to have a look at the taglayout sections of existing HTML

tag editors located in the \Extensions\TagDefs\HTML directory.