1. Martin Kruliš 17. 12. 2015 by Martin Kruliš (v1.1)1

2.  HTTP Request Wrapper ◦ Data are automatically prepared in superglobal arrays  $_GET – parameters from request URL  $_POST – parameters posted in HTTP body (form data)  $_FILES – records about uploaded files  $_SERVER – server settings and request headers  $_ENV – environment variables  HTTP Response ◦ Script output is the response ( echo …) ◦ Headers can be modified by functions – e.g., header('header-line'); 17. 12. 2015 by Martin Kruliš (v1.1)2

3.  Example 17. 12. 2015 by Martin Kruliš (v1.1)3 'op' => 'update' 'id' => '42' 'op' => 'update' 'id' => '42' 'name' => 'Martin' 'surname' => 'Kruliš' 'age' => '19' 'name' => 'Martin' 'surname' => 'Kruliš' 'age' => '19' $_GET$_POST

4.  Request Information ◦ Decoded to the $_SERVER array  REQUEST_METHOD – used method (“ GET ”or “ POST ”)  SERVER_PROTOCOL – protocol version (“ HTTP/1.1 ”)  REQUEST_URI – request part of URL (“ /index.php ”)  REMOTE_ADDR – clients IP address  HTTP_ACCEPT – MIME types that the client accepts  HTTP_ACCEPT_LANGUAGE – desired translation  HTTP_ACCEPT_ENCODING – desired encodings  HTTP_ACCEPT_CHARSET – desired charsets  + more info about the server and the client’s browser 17. 12. 2015 by Martin Kruliš (v1.1)4 phpinfo()

5.  File Uploads ◦ In form as  Provide safe way to browse disk files ◦ HTTP wrapper handles the file  Stores it in temporary location  Provide related info in $_FILES[name]  'tmp_name' – path to the file in temp directory  'error' – error code (e.g., UPLOAD_ERR_OK )  'name', 'type', 'size', … ◦ File exists only as long as the script runs  is_uploaded_file() – verification  move_uploaded_file() – a safe way to move files 17. 12. 2015 by Martin Kruliš (v1.1)5 Example 1

6.  Redirect Mechanism in HTTP ◦ 3xx response code  301 Moved Permanently  302 Found (originally named Moved Temporarily)  303 See Other ◦ Additional header ' Location ' has the new URL ◦ Browser must try to load the new URL ◦ Loops in redirections are detected  Creating Redirect in PHP ◦ header("Location: my-new-url"); ◦ Automatically changes the response code (to 302) 17. 12. 2015 by Martin Kruliš (v1.1)6

7.  Problem with POST 17. 12. 2015 by Martin Kruliš (v1.1)7 Client (Browser) Web Server POST Request (a submitted form) Response (a HTML page) script add/change something Refresh Again!!!

8.  Redirect (303 See Other) after POST 17. 12. 2015 by Martin Kruliš (v1.1)8 Client (Browser) Web Server POST Request Redirect (new URL) add/change something Refresh GET (new URL) HTML Page read-only Redirects to a new URL (without updating history) Example 2

9.  Redirecting Asynchronous HTTP Requests ◦ Works transparently – i.e., in the same way as all HTTP requests handled by the browser ◦ Typically unnecessary after POST requests  A script should not be re-executed after reload, thus it can receive the updated HTML immediately ◦ Uncertain semantics  Is the redirect meant for the AJAX result or should the whole page load a new URL? ◦ Efficiency  AJAX typically optimizes network utilization – additional redirect may be suboptimal 17. 12. 2015 by Martin Kruliš (v1.1)9

10.  Example – Replacing Redirect with AJAX ◦ Let us have a data table, where each item has a delete button that triggers AJAX POST request ◦ Trivial solution  After successful request, JS triggers reload of the page  Optionally the POST may send an URL (for location.href ) ◦ Slightly more optimized solution  After successful request, JS triggers reload of affected components (table) via separate AJAX GET request ◦ Optimized solution  The POST response sends a HTML fragment or (better yet) a difference update for the data table 17. 12. 2015 by Martin Kruliš (v1.1)10

11.  Cookies ◦ A way to deal with stateless nature of the HTTP ◦ Key-value pairs (of strings) stored in the web browser  Set by special HTTP response header  Automatically re-sent in headers with every request  Each page (domain) has it own set of cookies ◦ Cookies in PHP  Cookies sent by browser are loaded to $_COOKIE[]  Cookies are set/modified/removed by setcookie()  The function modifies HTTP response headers 17. 12. 2015 by Martin Kruliš (v1.1)11 Example 3

12.  Functions ◦ PHP have a huge arsenal of string functions  strlen(), substr(), trim(), split(), join(), … ◦ Libs for charset manipulation  Multibyte string lib  Iconv lib  Recode ◦ Functions for encoding (to URL, HTML, SQL, …)  urlencode(), urldecode()  htmlspecialchars(), htmlspecialchars_decode()  mysqli_real_escape_string() 17. 12. 2015 by Martin Kruliš (v1.1)12

13.  Regular Expressions ◦ String search patterns based on regular automata  Used for pattern matching, replacement, splitting, … ◦ POSIX syntax  Same syntax as in unix tools ( grep, sed, …)  Deprecated as of PHP 5.3 ◦ Perl (PCRE) syntax  Similar to POSIX syntax, but with more features  Separate set of functions in PHP ◦ Regular expression evaluation is implemented in C  May be faster than implementing string parsing in PHP 17. 12. 2015 by Martin Kruliš (v1.1)13

14.  MySQL ◦ Original mysql API is deprecated (as of PHP 5.5) ◦ MySQL Improved ( mysqli ) API  Dual object/procedural interface  Procedural interface is similar to original (deprecated) API  Advanced connectivity features  Persistent connections, compression, encryption  Directly supports transactions ◦ MySQL Native Driver ( mysqlnd ) extension  More direct access to MySQL server  Additional features (e.g., asynchronous queries) 17. 12. 2015 by Martin Kruliš (v1.1)14

15.  MySQLi Procedural API ◦ Establishing connection with MySQL server $mysqli = mysqli_connect("server", "login", "password", "db_name"); ◦ Performing queries $res = mysqli_query($mysqli, "SQL …"); ◦ Terminating connection mysqli_close($mysqli); ◦ MySQL statement wrapper functions mysqli_stmt_init($mysqli); mysqli_stmt_*(…) 17. 12. 2015 by Martin Kruliš (v1.1)15

16.  MySQL Results ◦ mysqli_query() result depends on the query type  On failure always returns false ◦ Modification queries return true on success ◦ Data queries ( SELECT, …) return mysqli_result obj  mysqli_fetch_assoc($res)  mysqli_fetch_obj($res)  mysqli_fetch_all($res, $format)  mysqli_fetch_fields($res)  mysqli_num_rows($res)  mysqli_free_result($res) 17. 12. 2015 by Martin Kruliš (v1.1)16 Example 4

17.  Zend Framework ◦ Developed by open community, supported by Zend ◦ Large and robust, based on MVC architecture  Build as independent modules (database, sessions, …)  Nette ◦ Popular PHP framework with Czech community ◦ Simple, easy to learn and use ◦ Modern approach (OO design, MVC, supports AJAX)  Dibi ◦ Database abstraction layer for PHP 17. 12. 2015 by Martin Kruliš (v1.1)17

18. 17. 12. 2015 by Martin Kruliš (v1.1)18