Magic __get method fails for data()

[cxj]

Accessing object properties via the magic __get() method does not work. Note that no exception is thrown, hence I don't think it is even called. This might be a PHP syntax special case, such as described in this block part way down the PHP Overloading page (php.net/__get):

Note:
The return value of __set() is ignored because of the way PHP processes the assignment operator. Similarly, __get() is never called when chaining assignments together like this:
$a = $obj->b = 8;

Can this be made to work? Is there a variation on calling data() in the TSS that can make it work in the current code? I tried a few variations, and can call __get explicitly via data(__get) but don't know how to pass the argument.

<?php
require_once "vendor/autoload.php";

$xml = '<h1>Original Title</h1>';

class Data {
    protected $data = array();
    public    $baz = 'Baz';

    public function __construct() {
        $this->data['foo'] = 'Foo';
        $this->data['bar'] = 'Bar';
    }

    public function __get($name) {
        if (array_key_exists($name, $this->data)) {
            return $this->data[$name];
        }
        throw new Exception("no such property");
    }

    public function getBar() {
        return $this->data['bar'];
    }
}

$output = new Data;

// this fails, using __get magic method.
$tss      = 'h1 {content: data(foo); }';
$template = new \Transphporm\Builder($xml, $tss);
echo $template->output($output)->body . PHP_EOL;

// this works, using explicit method.
$tss      = 'h1 {content: data(getBar); }';
$template = new \Transphporm\Builder($xml, $tss);
echo $template->output($output)->body . PHP_EOL;

// this works, using public property.
$tss      = 'h1 {content: data(baz); }';
$template = new \Transphporm\Builder($xml, $tss);
echo $template->output($output)->body . PHP_EOL;

[solleer]

When it checks to see if the method exists the check doesn't validate magic methods. I remember when this was removed a while ago. I will see why I requested that support be removed.

[cxj]

I grabbed a copy of the new-parser branch and ran my sample above against it.

The magic get of property foo via data(foo) stills fails as before, but now the data(getBar) calls also fails to return anything. I'm assuming there is an intentional backward compatibility break in the new parser.

If I change the data(getBar) to data(getBar()), then it works. That is an acceptable change.

Interestingly, that also means I can now call __get() directly via data(__get("foo")) and it works. It's kind of a hack to do that, but at least there is way to display my object's properties via Transphporm now with the new parser.

[solleer]

Correct. With the new parser, function calls must be explicit.

[cxj]

Thank you for the responses. I'd like to see the new parser merged to master. :)

[cxj]

Would still like to see PHP magic methods work, too.

[solleer]

I think this may have caused an issue with maphper earlier with magic methods being called at the wrong time

[solleer]

I think the problem before was that since functions weren't explicit it would call properties

[solleer]

This test passes

public function testDataObjCallMagicMethod() {
    $xml = "
    <div></div>
    ";

    $data = new Foo;

    $tss = "div { content: data(testCall()); }";

    $template = new \Transphporm\Builder($xml, $tss);

    $this->assertEquals('<div>test</div>', $template->output($data)->body);
}

class Foo {
    public $model;

    public function __construct() {
        $this->model = new Bar();
    }
    public function getBar($bar) {
        return $bar;
    }

    public function returnFalse() {
        return false;
    }

    public function returnTrue() {
        return true;
    }

    public function returnOne() {
        return 1;
    }

    public function add($a, $b) {
        return $a+$b;
    }

    public function __call($name, $args) {
        if ($name == "testCall") return "test";
        throw new \Exception();
    }
}

[solleer]

I assume this can be closed

[cxj]

I'm not completely sure. What's the proper syntax to access an object's public property under the new parser? That is, if I have:

    class Foo {
        public $bar = "bar";
    }
    $data = new Foo;

How do I write TSS to ask for $bar to be used as the content?

[solleer]

If foo is being passed as root data then
data(bar)

[cxj]

Does not work with magic method __get(). I admit it may be impossible, or more difficult than is worth the trouble to make it work. Here is my test case:

require 'vendor/autoload.php';

class getTest {

    private $data = array('a' => 'a', 1 => 1);

    public function __get($name) {
        echo " >>  Getting property '$name'\n";

        if (array_key_exists($name, $this->data)) {
            return $this->data[$name];
        }

        throw new Exception("no such property");

        return null;
    }
}

$data = new getTest;

$xml = "<div></div>\n";

$tss = "div { content: data(__get('a')); }";        // this works
$tss = "div { content: data(__get(1)); }";          // this works
$tss = "div { content: data(a); }";                 // fails
$tss = "div { content: data(1); }";                 // fails

$template = new \Transphporm\Builder($xml, $tss);

echo $template->output($data)->body;

[solleer]

The reason __get isn't called is because when traversing it uses isset to check if the property exists and isset doesn't call __get it does call __isset though

[cxj]

Ah! Thanks! Adding an __isset() magic method to my class makes my test work. :-)

    public function __isset($name) {
        if (array_key_exists($name, $this->data)) {
            return true;
        }
        return false;
    }

[cxj]

I just added __isset() functions to my production code. My unit testing passes. So I think this can be closed now.

[solleer]

This should definitely be documented to avoid future confusing.

[solleer]

I added some light documentation