ZPT Basics (part 2) - A Little Male Bonding
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Variables are the bread and butter of any programming language - and TAL is no exception. In TAL, variables are defined via the special "define" attribute, which must be provided with both a variable name and a value (which can be any valid TALES expression). Let's take a look at a simple example, which demonstrates:

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<h2>The name's <i tal:define="name string:Bond, James Bond" tal:content="string:$name">name here</i>.</h2>

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Here's how Zope renders it:

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The name's Bond, James Bond.

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In this case, the "define" attribute is used to define a variable named "name", and assign it the value "Bond, James Bond". The "string" keyword in the expression is used to indicate that the following text is - well - a string.

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<i tal:define="name string:Bond, James Bond" ... >name here</i>

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This value may then be accessed using a TAL "content" or "replace" attribute, in combination with the variable name (which must be prefixed by a dollar ($) symbol).

<i ... tal:content="string: $name">name here</i>

You can even set variable values dynamically, by using TALES expressions instead of hard-wired string values. Consider the following example, which illustrates:

<h1>The name's <i tal:define="whoami template/title_or_id"
tal:content="string:$whoami">name here</i>.</h1> 

Here's the output (assuming that the page title was "Agent007"):

The name's Agent007.

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