How to prevent echo in PHP and catch what it is inside?

Question

I have a function ( DoDb::printJsonDG($sql, $db, 1000, 2) ) which echos json. I have to catch it and then use str_replace() before it is send to the user. However I cannot stop it from doing echo. I don't want to change printJsonDG because it is being used in several other locations.

Answer 1

You can use the ob_start() and ob_get_contents() functions in PHP.

<?php

ob_start();

echo "Hello ";

$out1 = ob_get_contents();

echo "World";

$out2 = ob_get_contents();

ob_end_clean();

var_dump($out1, $out2);
?>

Will output :

string(6) "Hello "
string(11) "Hello World"

Answer 2

You can do it by using output buffering functions.

ob_start();

/* do your echoing and what not */ 

$str = ob_get_contents();

/* perform what you need on $str with str_replace */ 

ob_end_clean();

/* echo it out after doing what you had to */

echo $str;

Answer 3

Perhaps you can refactor DoDb:

class DoDb
{
    public static function getJsonDG( $some, $parameters )
    {
        /*
            original routine from printJsonDG without the print statement
        */

        return $result;
    }

    public static function printJsonDG( $some, $parameters )
    {
        print self::getJsonDG( $some, $parameters );
    }
}

That way you don't have to touch the code elsewhere in you application.

Answer 4

Check out output buffering, but I'd rather change the function now that it seems it'll be used for two things. Simply returning the string would be best.