PHP - AJAX voting

AJAX Voting

In the following example, we will demonstrate a voting program through which the voting results are displayed without refreshing the web page. show.

<!DOCTYPE html>
 <html lang="en">
     <meta charset="UTF-8">
         function getVote(int) {
             if (window.XMLHttpRequest) {
                 // IE7+, Firefox, Chrome, Opera, Safari 执行代码
                 xmlhttp=new XMLHttpRequest();
             } else {
                 // IE6, IE5 执行代码
                 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
             xmlhttp.onreadystatechange=function() {
                 if (xmlhttp.readyState==4 && xmlhttp.status==200)
 <div id="poll">
     <h3>你喜欢 PHP 和 AJAX 吗?</h3>
         <input type="radio" name="vote" value="0" onclick="getVote(this.value)">
         <input type="radio" name="vote" value="1" onclick="getVote(this.value)">


When the user selects one of the above options, a function named "getVote()" will be executed. This function is triggered by the "onclick" event.

getVote() function will perform the following steps:

· Create an XMLHttpRequest object

· Create a function that is executed when the server response is ready

· Send a message to the server File send request on

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

PHP file

The server page called above through JavaScript is a PHP file named "poll_vote.php":

 $vote = htmlspecialchars($_REQUEST['vote']);
 // 获取文件中存储的数据
 $filename = "poll_result.txt";
 $content = file($filename);
 // 将数据分割到数组中
 $array = explode("||", $content[0]);
 $yes = $array[0];
 $no = $array[1];
 if ($vote == 0)
     $yes = $yes + 1;
 if ($vote == 1)
     $no = $no + 1;
 // 插入投票数据
 $insertvote = $yes."||".$no;
 $fp = fopen($filename,"w");
   <span style="display: inline-block; background-color:green;
       width:<?php echo(100*round($yes/($no+$yes),2)); ?>px;
       height:20px;" ></span>
             <?php echo(100*round($yes/($no+$yes),2)); ?>%
   <span style="display: inline-block; background-color:red;
       width:<?php echo(100*round($no/($no+$yes),2)); ?>px;
             <?php echo(100*round($no/($no+$yes),2)); ?>%

When the selected value is sent from JavaScript to the PHP file, What will happen:

1. Get the contents of the "poll_result.txt" file

2. Put the file contents into a variable and add 1 to the selected variable

3. Write the results to the "poll_result.txt" file

4. Output the graphical voting results

##Text file

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

The data it stores is as follows:


The first number represents The number of votes for "Yes", the second number represents the number of votes for "No".

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

Next Section

<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>PHP中文网(</title> <script> function getVote(int) { if (window.XMLHttpRequest) { // IE7+, Firefox, Chrome, Opera, Safari 执行代码 xmlhttp=new XMLHttpRequest(); } else { // IE6, IE5 执行代码 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } xmlhttp.onreadystatechange=function() { if (xmlhttp.readyState==4 && xmlhttp.status==200) { document.getElementById("poll").innerHTML=xmlhttp.responseText; } }"GET","poll_vote.php?vote="+int,true); xmlhttp.send(); } </script> </head> <body> <div id="poll"> <h3>你喜欢 PHP 和 AJAX 吗?</h3> <form> 是: <input type="radio" name="vote" value="0" onclick="getVote(this.value)"> <br>否: <input type="radio" name="vote" value="1" onclick="getVote(this.value)"> </form> </div> </body> </html>
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