PHP development basic tutorial AJAX voting

     
  
 
你喜欢 PHP 和 AJAX 吗?
  
 是:  
否:  
 
  

element.

The form works like this:

• When the user selects "yes" or "no", an event is triggered

• When the event is triggered, the getVote() function is executed

• Surrounding the form is a

  named "poll". When data is returned from the getVote() function, the returned data replaces the form.

getVote() function will perform the following steps:

• Create XMLHttpRequest object

• Created in Function executed when the server response is ready

• Send a request to a file on the server

• Please note the parameter (q) added to the end of the URL ( Contains the contents of the drop-down list)

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PHP file:

The server called by JavaScript in the above paragraph The page is a PHP file named "2.php":

 
结果:
 
 
 
是:
 
  % 
 
 
 
否:
 
  % 
 
 

When the selected value is sent from JavaScript to the PHP file, what happens:

• Get" poll_result.txt" The contents of the file

• Put the file contents into the variable and add 1 to the selected variable

• Write the result" poll_result.txt" file

• Output graphical voting results

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##TXT file

The data from the voting program is stored in a text file (3.txt).

It looks like this:

0||0

The first number represents a "Yes" vote, and the second number represents a "No" vote.

Note: Remember to allow only your web server to edit this text file. Don't let anyone else gain access except the web server (PHP).

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##Learning experienceThis example mainly includes the following knowledge points:

Form basics: radio button

• ## onclick event: Occurs when the object is clicked

• Function call, function value passing

• Creation of AJAX XMLHttpRequest object, function executed when the server responds, sending request to the file on the server: See 1-5 for learning experience

• HTML DOM getElementById() method: Returns a reference to the first object with the specified ID

PHP related operations on files:

• file(): Read the entire file into an array

• fopen(): Open the file or URL

• fputs(): Write to file

• fclose(): Close an open file

Related functions:

• htmlspecialchars(): Convert predefined characters into HTML entities

• explode(): Break up the string For array