PHP关联数组：值的唯一函数

Question

So due to some nasty framework issues, I'm a little stuck here. Basically, I'm taking a string from user input, and replacing it with a value from my model that is only known at call time.

My structures are like so:

static public $placeholders = array("[REPLACE_STRING_1]"=>'firstName',
                                    "[REPLACE_STRING_2]"=>'DateTime->format(\'aa,bb\')');
//Problem line above.  Very messy, format is an arm long and painful

public function myfunction(ModelClass $master) {
    $body = $this->sampleService->get('samplebody'); // populate body from DB
    foreach(static::$placeholders as $key => $value){
        $body = str_replace($key, $master->value, $body);
    }
    return $body;
}

So this makes for some very ugly code. My boss would like to edit it to make for a function to be part of the array, assigned to each entry, that would run to filter/edit the code. Something like

function dateFormat($prop){
    return $prop->format('aa,bb');
}
function asIs($prop){
    return $prop;
}

static public $placeholders = array("[REPLACE_STRING_1]"=>['firstName', asIs]
                                    "[REPLACE_STRING_2]"=>['DateTime', dateFormat]);

Are there any existing structures or functions in PHP which make this possible, or is his code desire just a pipedream?

EDIT: I figured out a solution very similar to the answer posted below, but with a few modifications necessary to pass along variables.

function dateFormat ($prop, $master) {
    return $master->$prop->format('aabb');
}
function asIs ($prop, $master) {
    return $appointment->$prop;
}
static public $placeholders = array("[REPLACE_STRING_1]"=>['firstname','asIs'], 
                                    "[REPLACE_STRING_2]"=>['DateTime', dateFormat];

//instatiate service to get sampleService values

//main difference here
public function buildBody(ModelClass $master) {
    $body = $this->sampleService->get('samplebody');
    foreach(static::$placeholders as $key => $value){
        $body = preg_replace_callback('/'.preg_quote($key).'/',
        //Use closure here to pass in $master, otherwise laravel gets angry about strings instead of objects
        function ($matches) use ($master) {
            $placeholder = static::placeholders[$matches[0]];
            $func = $placeholder[1];
            $prop = $placeholder[0];
            return call_user_func(array($this, $func), $prop, $appointment);
        }, $body);
    }
    return $body;
}

All in all this was a very interesting problem for me, and I'm trying to find a way to clean it up even further. Going to mark your answer as correct, since it greatly helped get here.

Answer 1

If I got the question right, I'd go with preg_replace_callback and do it somewhat like this:

function dateFormat($prop){
    return $prop;
}

function asIs($prop){
    return $prop;
}

static public $placeholders = array(
    "[REPLACE_STRING_1]"=>['firstName', 'asIs'],
    "[REPLACE_STRING_2]"=>['DateTime', 'dateFormat']
);

private function replace($matches) {
    $placeholder = static::$placeholders[$matches[0]];
    $func = $placeholder[1];
    $prop = $placeholder[0];

    // this calls your class methods ('asIs', 'dateFormat')
    // with $prop = 'firstName' etc.
    return call_user_func(array($this, $func), $prop);
}

public function myfunction(ModelClass $master) {
    $body = $this->sampleService->get('samplebody');

    foreach(static::$placeholders as $key => $value) {
        // use a callback replace method instead of str_replace
        $body = preg_replace_callback('/' . preg_quote($key) . '/', array($this, 'replace'), $body);
    }

    return $body;
}