[eZ publish] fetch_alias() and fetch()

When going through the manual, we can know that, fetch_alias() can be thought of as a configuration-file based version of the fetch() operator.

But the fetch_alias() must be defined in configuration override for "fetchalias.ini", 

[fetch_alias_name]
Module=module_name
FunctionName=function_name
Parameter[parameter1]=fetch_alias_name1
Parameter[parameter2]=fetch_alias_name2
...
Constant[parameter3]=<any value>
Constant[parameter4]=<any value>
...

Directive	Description
Module	The name of the target module (for example "content").
FunctionName	The name of the target fetch function (for example "list").
Parameter	The "Parameters" array may be used to specify variables that will beset in the template(s). The "parameter_name" maps to the parameter nameused in normal fetch functions. The "fetch_alias_name" will be theparameter name used in the template(s).
Constant	Parameters that are defined as constants within the regular fetch function(s).

For example:

Configuration block:

[object]
Module=content
FunctionName=object
Parameter[object_id]=id

Template code:

{def $object=fetch_alias( 'object', hash( 'id', 1 ) )}

We can consider it Template code to be as follow:

{def $object = fetch(
                           "content",
                           "object",
                           hash(
                               "object_id", 1
                           )
                       )
}

More details, please click to view: http://ez.no/doc/ez_publish/technical_manual/4_x/reference/template_functions/miscellaneous/fetch_alias