PHP Key=>Value array using Static::Variables

Question

Can somebody tell me why this code is not working? It seems like the most efficient way to do the proposed task, I don't understand why I keep getting an error - even when I reverse the Key<>Value.

I am trying to replace #tags# within a text string/array with static::variables form an external class.

ERROR:

Parse error: syntax error, unexpected T_VARIABLE, expecting T_STRING in /home/content/57/10764257/html/marketing/includes/ProcessEmail.class.php on line 5

EXTERNAL CLASS:

class MyClass {
    public static $firstName = "Bob";    // Initally set as "= null", assigned
    public static $lastName = "Smith";   // statically through a call from
}                                        // another PHP file.

MAIN PHP FILE:

// This is the array of find/replace strings

private static $tags = array("#fistName#", MyClass::$firstName,
                             "#lastName#", MyClass::$lastName);

// This jumps trough the above tags, and replaces each tag with
// the static variable from MyClass.class.php

public static function processTags($message) {

    foreach ($tags as $tag => $replace) {
        $message = str_replace($tag, $replace, $message);
    }

}

But I keep getting that error...?

Thank you!

Answer 1

From http://php.net/manual/en/language.oop5.static.php

Like any other PHP static variable, static properties may only be initialized using a literal or constant; expressions are not allowed. So while you may initialize a static property to an integer or array (for instance), you may not initialize it to another variable, to a function return value, or to an object.

So you cannot use MyClass::$firstName as value for a static property.

Another solution is to use const instead of static. (PHP > 5.3)

class MyClass {
    const firstName = "Bob";
    const lastName = "Smith";
}

class MyClass2 {
    public static $tags = array(
        'firstName' => MyClass::firstName,
        'LastName'  => MyClass::lastName
    );
}

print_r(MyClass2::$tags);

Answer 2

Try replacing your code for:

<?php 
class MyClass {
    private static $tags = array(
        '#firstName#' => 'Bob',
        '#lastName#'  => 'Smith'
    );

    public static function processTags(&$message) {
        foreach (self::$tags as $tag => $replace) {
            $message = str_replace($tag, $replace, $message);
        }
    }
}


$message = 'Hello, my name is #firstName# #lastName#';
MyClass::processTags($message);
echo($message);

Result:

Hello, my name is Bob Smith