php从字段名称数组中获取对象数据

Question

I have a result set from a query that gives me an object that has dozens of fields, the below example is a subset:

[79] => stdClass Object
    (
        [name] => John Doe
        [email] => [e-mail]
        [ext] => 4004
        [options] => stdClass Object
            (
                [type] => friend
                [rating] => Excellent
                [context] => default
            )
        [address] => 123 Anywhere St
    )

Instead of plowing through each field, because I only want a handful of them, I am trying to use an array to get what i want:

$fields = array('name','email','options->type','options->rating','address');

so then i do:

foreach ($result as $k => $v){
    foreach ($fields as $kk => $vv){
        echo $kk. " - " . $v->$kk."<br>";
    }
}

Which gives me field name and its value.

name - John Doe
email - [e-mail]
address - 123 Anywhere St.

However, anything in that sub object(options) is giving me a blank result.

Answer 1

You can use a recursive function providing that you don't mind changing the format of your $fields var to include arrays. In my opinion this makes it easier to read anyway, and easier to handle in code.

The benefit of using a recursive function is that it will handle any depth.

$o = (object) [
    'name' => 'John Doe',
    'email' => '[e-mail]',
    'ext' => 4004,
    'options' => (object) [
        'type' => 'friend',
        'rating' => 'Excellent',
        'context' => 'default',
        'any' => (object) [
            'depth' => (object) [
                'will' => 'work'
            ]
        ]
    ],
    'address' => '123 Anywhere St'
];
$fields = [
    'name',
    'email',
    'options' => [
        'type',
        'rating',
        'any' => [
            'depth' => [
                'will'
            ]
        ]
    ],
    'address'
];

function getObjectProps($o, $fields, $parent = '') {
    if (strlen($parent)) {
        $parent .= '->';
    }
    foreach ($fields as $k => $v) {
        if (is_array($v)) {
            getObjectProps($o->{$k}, $v, $parent . $k);
        } else {
            echo $parent . $v . ' - ' . $o->{$v} . '<br/>';
        }
    }
}
getObjectProps($o, $fields);

Output:

name - John Doe
email - [e-mail]
options->type - friend
options->rating - Excellent
options->any->depth->will - work
address - 123 Anywhere St