1. PHP A very brief introduction PHP1

2. PHP = PHP: Hypertext Processor A recursive acronym! PHP scripts are executed on the server side Executed by (a plugin to) an application server An HTTP server + more We will use the Apache HTTP server PHP can help developers make dynamic web pages As opposed to static web pages PHP is open source PHP competitors Microsoft ASP.NET Oracle JavaServer Faces (JSF) Python Ruby on Rails … many others PHP2

3. Application stacks Application stack Application server + Database + programming language AMP stack Apache, MariaDB/MySQL, PHP LAMP = Linux + AMP WAMP = Windows + AMP XAMP = any OS + Amp We will use XAMP MEAN stack MongoDB, Express JS, Angular JS, Node JS Microsoft IIS, Microsoft SQL Server, ASP.NET PHP3

4. PHP basic syntax PHP is (small) pieces of code written inside ordinary HTML …. … … The PHP code is executed by the application server. The resulting (echo) HTML etc. is sent to the client. The PHP code is not sent to the client Browsers cannot execute PHP PHP comments // The rest of the line is a comment /* multi-line comment …. */ PHP4

5. PHP variables PHP variables start with $ A variable can have a short name (like x and y) or a more descriptive name (age, carName, total_volume). Rules for PHP variables: A variable starts with the $ sign, followed by the name of the variable A variable name must start with a letter or the underscore character A variable name cannot start with a number A variable name can only contain alpha-numeric characters and underscores (A-z, 0- 9, and _ ) Variable names are case-sensitive ($age and $AGE are two different variables) Source http://www.w3schools.com/php/php_variables.asp PHP5

6. PHP data types Variables can store data of different types, and different data types can do different things. PHP supports the following data types: String “content of the string” Integer Float (floating point numbers - also called double) Boolean: true, false Array Object NULL Resource Arrays PHP6

7. Type systems Strongly typed language Each variable, identifier, etc. has a type Variable etc. do not change type at run-time Explicit type conversion C#, Java Weakly typed language Variables, etc. may have a type Variables, etc. can change type at run- time Type conversion generally not needed PHP, JavaScript Example: phpTypes Static type checking Types are checked at compile-time Bugs are caught early C#, Java Dynamic type checking Types are checked at run-time Bugs are caught late Help from IDEs IDES like Visual Studio, NetBeans, etc. provide more help for programmers of a strongly + statically typed language. PHP7

8. PHP forms A form is a place for the user to submit some data to the system. Usually 2 pages are involved The page with the input form Another page to handle the input Example: firstform PHP8

9. PHP super globals PHP offers a number of so-called super globals. They are defined automatically Examples $_POST: Access to data from forms send with the POST HTTP method $name = $_POST[“name”]; $_GET: Access to data from forms send with the GET HTTP method http://www.w3schools.com/php/php_superglobals.asp PHP9

10. PHP conditions If statements Similar to C#, with an extra elseif If If … else If … elseif http://www.w3schools.com/php/php_if_else.asp Switch statement Similar to C# http://www.w3schools.com/php/php_switch.asp PHP10

11. PHP loops While and do … while Similar to C# While has test at the entry Do … while has test at the exit At least one turn in the loop http://www.w3schools.com/php/php_looping.asp For and foreach Similar to C# Foreach element in an arrays http://www.w3schools.com/php/php_looping.asp PHP11

12. PHP functions Comparable to C# methods Functions can return a value Many API functions return False if there is no proper result In C# the method would throw an exception Something of a different type if there is a proper result Functions can have parameters Functions can have local variables Only visible inside the function (like C# methods) Example: phpTypes PHP12

13. PHP classes PHP classes are similar to C# classes Private + public fields Private + public functions Constructors The syntax for referring to member (field or function) is slightly different C# obj.method(param) PHP obj -> function(param) Example: ClassExample PHP13

14. PHP arrays Stores multiple values in a single variable Basic syntax (http://www.w3schools.com/php/php_arrays.asp) Iteration foreach ($array as $value) { code to be executed; } Three types of arrays Indexed arrays: Indexes 0, 1, 2, … Associative arrays: (key, value)-pairs Alias Map alias Dictionary Multi-dimensional arrays: arrays containing arrays PHP14

15. PHP exception handling Syntax Try { …. } Catch (Exception ex) Throw new Exception(“….”); Similar to C# Exception classes Class MyException extends Exception { … } PHP15

16. Cookies in HTTP Cookies are part of the HTTP standard. Cookies are small pieces of information Generated on the server and send to the client in a response Stored on the client Sent back to the same server in sub- sequent requests HTTP state The server is stateless The client can store state as cookies Cookie content Name, value, expiration, domain, etc. Cookies can be attached to all kinds of documents Text, CSS, images, even 1x1 pixel images! Usages To identify users ID cookie: Used as a key to a database on the server side Users preferences, etc. Watch your cookies Firefox: Options -> Privacy -> remove individual cookies PHP16

17. Cookies in PHP Set cookie Setcookie(name, value, expiration) Make a new cookie Change an existing cookie Same name Get the value of a cookie $_COOKIE[$cookie_name] Ask if a cookie exists isset($_COOKIE[$cookie_name]) Useful before you try to get the value If you try to get the value of a non- existing cookie your program fails Delete a cookie Unset($_COOKIE[$cookie_name]) Example cookieExample PHP17

18. Sessions in general Most application servers are not totally stateless. Session state is kept on the server Each user has a session Many users = many sessions The session is alive as long a the user is using the web site In real life there is a timeout, typically 30 minutes The session is like a map / dictionary / associative array List of (key, value)-pairs The key is a string The value might be anything Time Number Shopping cart Sessions are usually implemented using a session cookie The server finds your session based on your session cookie PHP18

19. Sessions in PHP Set $_SESSION[“name”] = $value; Get $value = $_SESSION[“name”]; Ask if there is an entry in the session If (isset($_SESSION[“name”]) { …} Example: sessionExample Starting the session Put this in the top of the PHP file using sessions Clean the session Session_unset() You are left with an empty session Remove the session Session_destroy() You are left with no session PHP19

20. PHP consuming SOAP/WSDL web services The tool wsdl2php reads WSDL file and produces PHP classes according to the file. Import the generated PHP file into your PHP file Require_once $filename. Use the generated classes Example PhpCurrencySoapConsumer PHP20

21. PHP consuming REST web services Two stages 1.Make a GET request and get the response body (XML or JSON) 2.Read the response body and convert it into a more useful format GET request can be send in two ways With curl $client = curl_init($uri); curl_setopt($client, CURLOPT_RETURNTRANSFER, true); // default: false, curl_exec returns true/false $response = curl_exec($client); curl_close($client); With file_get_contents $response = file_get_contents($uri); Make a useful format: associative arrays $convertToAssociativeArray = true; $arr= json_decode($jsondata, $convertToAssociativeArray); echo $arr['Title']; Example PhpConsumeRestService PHP21