Entities
March 29, 1999
To a large degree, much of the discussion of entities is more
relevant in the next section, writing "valid" documents,
rather than in this section, writing "well-formed"
documents.
As such, we will discuss entities in greater details in the
next section.
Nevertheless, some issues make sense within this section,
because entities must be well-formed as well as valid. So,
in this section, we will introduce entities in terms of
their basic syntax and leave the nitty-gritty for a little bit
later.
As we said before, entities are essentially aliases that allow
you to refer to large sections of text without having to type
them out every time you want to use them.
Suppose you have your letterhead saved as an entity in a shared
file. Then, every time you write a letter in XML, you might
say something like:
<LETTER>
&letterhead;
<TO>Bob Frog</TO>
<BODY>
blah blah blah
</BODY>
<FROM>Kevin Kelly</FROM>
</LETTER>
Notice that the letterhead might expand out to
My Company
1234 Fifth Ave.
Suite 1256
Los Angeles, California 90026
However, instead of typing that out in every letter, you just use
&letterhead;
There are two types of entities, general and parameter entities,
and each entity has two parts, the declaration and the entity
reference.
Processing Instructions
Introduction to XML For Web Developers | Table of Contents
General Entities
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