str_replace text with PHP - php

Question

My users want to be able to have a contact form on their website. Understandable. But it's not really working out.
<?php
function ubbreplace($text){
$text = str_replace("[contact-form]",'<?php include("contactform.php"); ?>',$text);
return $text;
}
?>
The include is not including the contact form. Why is that?

Answer 1

The str_replace function that you're using is working as expected. If you don't see anything in your browser, view the source code and you'll see a <?php tag within your HTML code.
The output is the stuff that normally goes to your browser. A buffer is a cache of data. Output buffer is a cache of data that would have normally gone to your browser, but didn't because you buffered it instead.
To get your desired results, we need to grab the contents of the contactform.php file and replace [contact-form] with those contents. We can do this by capturing the output from the contactform.php into a variable and using that variable as the replacement.
<?php
function ubbreplace($text){
if(strpos($text, '[contact-form]') !== false) {
ob_start();
require 'contactform.php';
$replace = ob_get_contents();
ob_end_clean();
$text = str_replace('[contact-form]', $replace, $text);
}
return $text;
}
$content = ubbreplace('Hello world! [contact-form]');
echo $content;
?>

Answer 2

You are approaching the concept entirely from the wrong end, what you are doing is working with strings, and these strings will not be processed by PHP as functions, or includes or other core markup.
you can insert variables into a string but this happens at execution time, and the string will not then be re-executed (and also ignores the fact the include is not a variable at all but is a language construct).
So, what can you do about this? Well - rearrange your code with the logic that:
You have a string you want to find, and then act once it's been found.
So, to do this try this code logic (customise, obviously). You want to find the "flag" you have set and then replace it with a correct marker,
<?php
if( stripos($text,"[contact-form]") !== false){
include("contactform.php");
}
?>
The above will maybe not do exactly as you intend, because its behaviour depends heavily on what is inside the included PHP file.
You will maybe have to rearrange your include contents (you can return data from an include if you really need to, but I don't really recommend that).
As a small improvement I would also recommend using mb_stripos() function instead of the standard stripos();.
So to get a cleaner more usable result, set the contents of the include to a variable such as $contactForm = "HTML contact form data"; and then always run the include, but only output the contents if the flag is found:
include contains:
$contactForm = "Some HTML contact data";
parent file contains:
<?php
include("contactform.php");
if( stripos($text,"[contact-form]") !== false){
print $contactForm;
}
?>
Or what is very probably easier for you to implement is:
<?php
include("contactform.php");
function ubbreplace($text){
$text = str_replace("[contact-form]",$contactForm,$text);
return $text;
}
?>
Include in the PHP manual, Please note references to return values
Splash58's Answer (and Brogans Answer) of using output buffering is also a perfectly
good solution and saves a lot of the effort of quantifying included output into
varaibles in my answer, although my answer is primarily to explain the
purpose and the failings of your original question.
Given a completely open option I would choose to use Output buffering
to solve this issue but you do need to know what's going on, so if
output buffering is new to you definitely read up on it first.

Answer 3

function ubbreplace($text){
if (strpos($text, "[contact-form]") !== false) {
ob_start();
include("contactform.php");
$replace = ob_get_contents();
ob_end_clean();
$text = str_replace("[contact-form]", $replace, $text);
}
return $text;
}