PHP - How to replace special characters for url

Question

I am trying to convert special characters (eg. +, /, &, %) which I will use them for a GET request. I have constructed a

Answer 1

There is a built-in PHP function for this, which is a far better option than doing it manually.

urlencode - built in function from php

However, if you still want to do it manually:

function convert_text($text) {

$t = $text;

$specChars = array(
    '!' => '%21',    '"' => '%22',
    '#' => '%23',    '$' => '%24',    '%' => '%25',
    '&' => '%26',    '\'' => '%27',   '(' => '%28',
    ')' => '%29',    '*' => '%2A',    '+' => '%2B',
    ',' => '%2C',    '-' => '%2D',    '.' => '%2E',
    '/' => '%2F',    ':' => '%3A',    ';' => '%3B',
    '<' => '%3C',    '=' => '%3D',    '>' => '%3E',
    '?' => '%3F',    '@' => '%40',    '[' => '%5B',
    '\\' => '%5C',   ']' => '%5D',    '^' => '%5E',
    '_' => '%5F',    '`' => '%60',    '{' => '%7B',
    '|' => '%7C',    '}' => '%7D',    '~' => '%7E',
    ',' => '%E2%80%9A',  ' ' => '%20'
);

foreach ($specChars as $k => $v) {
    $t = str_replace($k, $v, $t);
}

return $t;
}

place the key and value in the last so that the last iteration of loop will be for spaces

Answer 2

Do not use a loop.

Use str_replace

str_replace($entities, $replacements, $string);

Or better use this native PHP function rawurlencode

Answer 3

You can use rawurlencode($url) builtin function.

<?php
$url='http://fb.com';
echo rawurlencode($url);

the output:

http%3A%2F%2Ffb.com

Answer 4

Because all your replacements have a percentage (%) character in them, you have to first replace all the occurrences of % with its equivalent %25. Afterwards you should replace other characters such as space and so on. An when you try to convert back the encoded url to its original state, % character should be the last character that you convert back. Convert back your array in reverse order. use array_reverse() function to reverse the order of elements of $specChars. In other words you have to use two separate functions for encoding and decoding your urls.

The following functions are the ones I have written myself to do the job.

   $arrayChrs = array('%',' ','!');
   $arrayChrs = array('%25', '%20','%21');

 function encodeData($subject)
    { //enode data
    global $arrayCodes;
    global $arrayChrs;
    if (!is_null($arrayChrs) && !is_null($arrayCodes)) {
        $arCnt1 = count($arrayChrs);
        $arCnt2 = count($arrayCodes);
        if ($arCnt2 == $arCnt1) {
            for ($x = 0; $x <= ($arCnt2 - 1); $x++) {
                $code1 = $arrayCodes[$x];
                $char1 = $arrayChrs[$x];
                $code_encoded = utf8_encode($code1);
                $char_encoded = utf8_encode($char1);
                $subject = str_replace($char_encoded, $code_encoded, $subject);

            }
        }
    }

    return $subject;
}

//[end function]




function decodeData($subject)
{ //decode data
    global $arrayCodes;
    global $arrayChrs;
    $outputStr = $subject;
    if (!is_null($arrayChrs) && !is_null($arrayCodes)) {
        $arCnt1 = count($arrayChrs);
        $arCnt2 = count($arrayCodes);
        if ($arCnt2 >= 1 and $arCnt2 == $arCnt1) {
            if ($arCnt2 >= 1) {
                for ($x = ($arCnt2-1); $x >=0; $x--) {
                    $code1 = $arrayCodes[$x];
                    $char1 = $arrayChrs[$x];
                    $code_encoded = utf8_encode($code1);
                    $char_encoded = utf8_encode($char1);
                    $outputStr = str_replace($code_encoded, $char_encoded, $outputStr);
                }

            }


        }

    }
    return $outputStr;
}

//[end function  ]

Notice that one for loop counts elements forward by using $x++, and the other one counts elements in reverse order by using $x--.

Elements in $arrayChrs are replaced by elements in $arrayCodes during encoding. During decoding the reverse replacement takes place.

Answer 5

Wouldn't you be better off using the PHP build in functionality to do this: rawurlencode?

Answer 6

There's already a function for this in the standard PHP library: rawurlencode.