ZPT-JS reference - Attributes

Syntax

argument       ::= declare_item [';' declare_item]*
declare_item   ::= ('required') variable_name (variable_type (expression))
variable_name  ::= Name
variable_type  ::= Name

Description

The data-declare statement declares a list of variables and some settings about them.

Each declaration can define:

The required reserved word declares a required variable. It is optional. The default value is false.
The variable name. It is the only mandatory item.
The variable type (optional). It declares the type of the variable.
An expression working as default value (optional). It is evaluated only if the value of the variable is undefined.

Some example of types:

Type	Value example
number	NaN
number	5
array	[]
string	'any string'
function	function(){}
regexp	/a/
date	new Date()
object	{}
myconstructor	new MyConstructor()

Any value matches undefined or null types.

A strict mode is set to true inside the node with this attribute. Strict mode makes it easy to force to declare variables. If strict mode is true and ZPT-JS finds a not declared variable an error occurs. Strict mode can be defined in two ways:

Using a data-declare attribute. All the variables used in this node must be declared.
Using zpt.context.setStrictMode( true ). All the variables used in the root node must be declared.

An error occurs if:

A non declared variable is found.
The value of a required variable is undefined.
The type of a variable does not match with the declared one.

If an error occurs ZPT-JS stop processing the nodes and show the error (using a javascript alert by default). ZPT-JS uses the errorFunction defined in context. To customize it use the setErrorFunction in context.

Differences with ZPT

This statement does not exist in ZPT.

Examples

Declaring a number, a string, an array and a date:

data-declare="aNumber number;
              aText string;
              anArray array;
              aDateValue date"

Declaring a number, a string, an array and a date (all required):

data-declare="required aNumber number;
              required aText string;
              required anArray array;
              required aDateValue date"

Declaring a required variable (no type):

data-declare="required myVar"

Declaring some default values:

data-declare="aNumber number 99;
              aText string 'a default value'"

ZPT-JS reference - Attributes - TALDeclare

Syntax

Description

Differences with ZPT

Examples