Optional API arguments cannot be skipped

[ewinslow]

I have exposed the following function:

function rest_test($one = 1, $two = 2)
{
	return $two/$one;
}

expose_function(
	'system.api.test',
	'rest_test',
	array(
		'one' => array('type' => 'int', 'required' => FALSE),
		'two' => array('type' => 'int', 'required' => FALSE),
	)
);

If I call

...?method=system.api.test&two=1&one=2

it does what you think it should, returns 0.5. However,

...?method=system.api.test&two=1

does not do what you think it should. Instead of returning 1, it still returns two, because the argument for one is completely missing.

Right now to get around this I'm having my users do

?method=api.func&opts[arg1]=val1&opts[arg2]=val2

but this is hardly ideal. It seems so unnecessary when they're already named arguments to have to specify them as an array like that.

[cash]

There is no way to call your function in php only specifying the second parameter.

To support this kind of use of optional parameters, we would have to change all exposed methods so that they support a single parameter similar to the new elgg_get_entities() function.

This is very important so I'll give it some more thought. If anyone has a suggestion, please share. Right now I'm leaning toward adding a version parameter to expose_function. If a developer specifies the new version, the function must support the parameters passed as an associative array. Otherwise, it works as before. This would allow us to support your usage while not breaking everyone else's code. I'd deprecate the old usage after a few releases.

[ewinslow]

Why not just pass NULL into arguments that weren't specified? Or better yet, allow expose_function to specify a default.

expose_function(
    'func.name',
    'func_name',
    array(
        'param1' => array('type' => 'int', 'required' => 'false', 'default' => 10),
        'param2' => array('type' => 'string', 'required' => 'false', 'default' => ''),
        'param3' => array('type' => 'array', 'required' => 'false', 'default' => array()),
    ),
)

You could even default 'required' to FALSE if 'default' is specified.

[cash]

I agree!

[cash]

Huh, I should have checked the code before commenting on this. It already works with default parameters. I added 8 months ago and forgot that I did this.