Loop(3)

NAME
HTML::Macro::Loop - looping construct for repeated HTML blocks

SYNOPSIS
  use HTML::Macro;
  use HTML::Macro::Loop;
  $ifp = HTML::Macro->new();
  $loop = $ifp->new_loop('loop-body', 'id', 'name', 'phone');
  $loop->push_array (1, 'mike', '222-2389');
  $loop->push_hash ({ 'id' => 2, 'name' => 'lou', 'phone' => '111-2389'});
  $ifp->print ('test.html');

DESCRIPTION
  HTML::Macro::Loop processes tags like
<loop id="loop-tag"> loop body </loop>

    Each loop body is treated as a nested HTML::Macro within which variable
substitutions, conditions and nested loops are processed as described under
HTML::Macro.
    Each call to push_array and push_hash inserts a new loop iteration.
When the loop is evaluated these iterations are used (in the order they
were inserted) to create HTML::Macros that are applied to the loop body.
push_hash is analogous to HTML::Macro::set_hash; it sets up multiple variable
substitutions.  push_array must be used in conjunction with declare.
declare provides the list of keys that are implicitly associated with the
values in the corresponding positions in the argument list of push_array.
    An HTML::Macro::Loop object is associated with a loop tag by setting it to
the value of the loop tag in an HTML::Macro.  This has the effect that the
name spaces of page variables and loop tags overlap.
For example:

    $ifp->set ('loop-tag', $loop);
Ordinarily, however, loops are created using the HTML::Macro::new_loop function. This first argument to new_loop is the loop tag; all subsequent arguments are loop keys.

Each iteration of the loop, created by calling push_arry or push_hash, sets a value for each of the declared loop keys. If keys are not declared explicitly using new_loop, they may be declared implicitly by the first call to push_hash. The number of elements in the arrays passed to push_array must match the number of declared loop keys.

HTML::Macro::Loop::pushall_arrays is a shortcut that allows a number of loop iterations to be pushed at once. It is typically used in conjunction with DBI::selectall_arrayref.

Variable substitution within a loop follows the rule that loop keys take precedence over "global" variables set by the enclosing page (or any outer loop(s)).

AUTHOR
Michael Sokolov, sokolov@ifactory.com

SEE ALSO HTML::Macro
perl(1).