PHP instance AJAX Vote
AJAX Vote
In the following examples, we will demonstrate a voting procedure through which the voting results are displayed in the case where the page is not refreshed.
Do you like PHP and AJAX do?
Examples explain - HTML page
When the user selects an option above to execute named "getVote ()" function. This function is triggered by the "onclick" event.
poll.html file code is as follows:
<html> <head> <meta charset="utf-8"> <title>本教程(w3big.com)</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; } } xmlhttp.open("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>
getVote () function performs the following steps:
- Create XMLHttpRequest object
- Create function when the server is ready to perform the response
- File on the server to send requests
- Please note added to the end of the URL parameter (q) (contains the contents of the drop-down list)
PHP File
Above this server page called by the JavaScript is called "poll_vote.php" PHP files:
<?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"); fputs($fp,$insertvote); fclose($fp); ?> <h2>结果:</h2> <table> <tr> <td>是:</td> <td> <span style="display: inline-block; background-color:green; width:<?php echo(100*round($yes/($no+$yes),2)); ?>px; height:20px;" ></span> <?php echo(100*round($yes/($no+$yes),2)); ?>% </td> </tr> <tr> <td>否:</td> <td> <span style="display: inline-block; background-color:red; width:<?php echo(100*round($no/($no+$yes),2)); ?>px; height:20px;"></span> <?php echo(100*round($no/($no+$yes),2)); ?>% </td> </tr> </table>
When the selected value is sent from JavaScript to PHP file will occur:
- Get Content "poll_result.txt" file
- The contents of the file into a variable, the variable selected to be incremented by 1
- Writes "poll_result.txt" File Results
- Graphical output of poll results
Text File
Text File (poll_result.txt) storing data from the voting procedure.
It stores the data as follows:
3||4
The first number indicates "Yes" vote count, and the second number represents the "No" vote count.
Note: Remember to only allow your Web server to edit the text file.Do not let other people get access, in addition to Web server (PHP).