Iterator support esoteric behavior (keys)

[ktomk]

I just run over this yesterday while using Mustache. I think it's worth to share if someone runs into the same problem. I had an iterator that was keyed starting with 1.

While using it for a Mustache section, the section was rendered (once) but did not contain any sub values (Not using a pragma).

I wondered about that and checked out the tests in specific the one which iterates over an array. I rebuild that test scenario in my template and used the testdata as a comparison which did work. The testdata array is default keyed.

As this was the only difference I changed my keying to start with 0 instead of 1. This did the trick for the moment.

While I wanted to reproduce this yesterdays behavior to make a more specific issue report here today, I was not able to reproduce this any longer (!).

So if someone runs over a similar problem, in the end the fix was easy for me. I'm a bit disappointed because I can not reproduce it right now even when I revoke the changes I made to fix the problem.

[Yahasana]

In the implicit_iterator/ImplicitIterator.php, make a little change to the start key of the array. it'll not work.
class ImplicitIterator extends Mustache {
protected $data = array(1 => 'Donkey Kong', 'Luigi', 'Mario', 'Peach', 'Yoshi');
}

[bobthecow]

The current functionality is by design: Because PHP uses the same primitive for hashes and arrays, Mustache needs some way of determining whether a variable is iterable (i.e. an indexed array) or not (i.e. an associative array).

The current implementation assumes that if an array does not have consecutive, zero-based array keys, it must be an associative array. And, if an array is an associative array, it is not "iterable" in the mustache sense of the word.

[Yahasana]

Why not let the associative array iterated ? I cannt see the syntax {{%IMPLICIT-ITERATOR}}{{.}} in the mustache manual. however, you have implemented in mustache.php, you do good job. why not let that much more powerful? I just want to know that it's a technique problem or is going against the muastache philosophy.

[bobthecow]

Actually, it's not a matter of letting this implementation of Mustache be 'more powerful'. The current functionality is fundamental to Mustache. Given this view:

$view = array(
    'things' => array(
        array('name' => 'foo'),
        array('name' => 'bar'),
        array('name' => 'baz'),
    ),
    'stuff' => array(
        'name' => 'qux',
    ),
);

And this template:

{{things}}
 * {{name}}
{{/things}}

You'll get something like:

 * foo
 * bar
 * baz

But if you use the stuff variable instead:

{{stuff}}
 * {{name}}
{{/stuff}}

You would get:

 * qux

This is because, in Mustache, a section is either for or if, depending on the value of the variable referenced. The templates above resolve to (approximately) this in PHP:

<?php foreach ($things as $thing): ?>
 * <?php echo $thing['name']; ?>
<?php endforeach; ?>

and

<?php if (!empty($view['stuff'])): ?>
 * <?php echo $view['stuff']['name']; ?>
<?php endif; ?>

In the case of {{stuff}}, if we iterated over associative arrays it would render this instead:

 *

You could see how this is a problem, right?