PHP Output Buffer

0-PHP-OUTPUT-BUFFER.MD

PHP OUTPUT BUFFER

https://code-boxx.com/php-output-buffering/

LICENSE

Copyright by Code Boxx

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

1-ob-start-flush.php

<?php
// (A) START BUFFERING
ob_start();

// (B) HOLD "HELLO" AND " WORLD" IN THE BUFFER
echo "hello";
echo " world";

// (C) RELEASE "HELLO WORLD" AS SINGLE OUTPUT
// NOTE: PHP WILL AUTO-FLUSH AT END-OF-SCRIPT EVEN IF OB_FLUSH() IS OMITTED
ob_flush();

2-ob-clean.php

<?php
// (A) START BUFFERING
ob_start();

// (B) HOLD "HELLO" AND " WORLD" IN THE BUFFER
echo "hello";
echo " world";

// (C) CLEAN THE BUFFER
ob_clean();

// (D) NOTHING WILL OUTPUT SINCE THE BUFFER IS EMPTY NOW
ob_flush();

3-ob-no-stop.php

<?php
// (A) START BUFFERING
ob_start();

// (B) BUFFER NOW HOLDS "HELLO WORLD"
echo "hello";
echo " world";

// (C) CLEAN - BUFFER NOW EMPTY
ob_clean();

// (D) OUTPUT BUFFERING IS STILL ON!
// BUFFER NOW HOLDS "FOO BAR"
echo "foo";
echo " bar";
ob_flush();

4-ob-end.php

<?php
// (A) HOLD "HELLO WORLD" IN BUFFER
ob_start();
echo "hello ";
echo "world";

// (B) STOP BUFFERING
// (B1) END CLEAN
// EMPTY BUFFER + STOP STOP BUFFERING (NOTHING WILL OUTPUT)
// ob_end_clean(); 

// (B2) END FLUSH
// OUTPUT "HELLO WORLD" + STOP BUFFERING
ob_end_flush();

// (C) BACK TO "NORMAL OUTPUT"
echo "foo bar"; // IMMEDIATELY OUTPUT "FOO BAR"

5-ob-get.php

<?php
// (A) HOLD "HELLO WORLD" IN BUFFER
ob_start();
echo "hello world";

// (B) GET BUFFER LENGTH (IN BYTES)
echo " - ".ob_get_length()." bytes";

// (C) GET OUTPUT BUFFER
// (C1) GET - SIMPLY "COPY" BUFFER INTO VARIABLE
$buff = ob_get_contents();

// (C2) GET CLEAN  - "MOVE" BUFFER INTO VARIABLE, EMPTY BUFFER
// $buff = ob_get_clean();

// (C3) GET FLUSH - OUTPUT BUFFER + COPY TO VARIABLE
// $buff = ob_get_flush();

// (D) WHAT'S IN $BUFF?
ob_end_clean();
echo $buff;

6a-products.php

<?php
$products = [
  [
    "name" => "Foo Bar",
    "price" => "12.34"
  ],
  [
    "name" => "Poo Bar",
    "price" => "22.33"
  ],
    [
    "name" => "Goo Bar",
    "price" => "33.44"
  ]
];

6b-html.php

<?php
// (A) USE STATIC HTML PAGE IF EXISTS
if (file_exists("products.html")) { require "products.html"; }

// (B) GENERATE + SAVE PAGE IF NOT
else {
  // (B1) GET PRODUCTS
  require "6a-products.php";

  // (B2) START BUFFERING
  ob_start();

  // (B3) OUTPUT PRODUCTS HTML
  foreach ($products as $p) {
    echo "<div>".$p["name"]."</div>";
    echo "<div>".$p["price"]."</div>";
  }

  // (B4) SAVE AS STATIC HTML
  file_put_contents("products.html", ob_get_contents());
  ob_end_flush();
}