php- 更新 fwrite 提交后不刷新

php- update fwrite without any refresh after submit

我正在使用此 php 代码来编辑 .txt 文件并更新它。

<?php
    $fichier=text.txt";

        if(isset($_POST['update'])) {    
        $ouverture=fopen("$fichier","w"); 
        fwrite($ouverture,"$_POST[modif]"); 
        fclose($ouverture); 
        echo '<h2>Modification effectue</h2>'; // validation
        }
?>
<form method="post" action=""> 
<textarea name="modif">
<?php 
if(is_file($fichier)) echo file_get_contents($fichier); 
?>
</textarea>
<input type="submit" name="update">update</input>
</form>

代码独立运行,但一旦在我的最终网站结构上实施,提交后的刷新效果将我带到网站的根目录(+脚本未保存)。

有没有不用刷新页面就可以用fwrite更新的方法?

/已找到解决方案/ 从那个问题推导出

index.php

    <script>
    //when you click save changes, we get its id="save"
    //and prevent default submission    
    $(document).on("click", "#save", function(e){   
            e.preventDefault();
            //get the textarea data bu its id="demo"
            var textdata = $('#demo').val();
            mydata= 'testdata='+textdata;
            $.ajax({
                type:'POST',
                data:mydata,
                url:'update.php',
                success:function(data) {                
                    if(data){
                      alert('Saved!');
                      $("#demo").html(data);//load data from update.php
                    }else{
                      alert('Update failed');
                    }
                  }
            });
        });
    </script>

    <form method="POST">
            <?php
            $myfile = fopen('test.txt', 'r');
              echo "<textarea id='demo'>";
            // go through each line in the file, print its contents.
            while(!feof($myfile)) {
              echo fgets($myfile);
            }
              echo "</textarea><br>";
            ?>    
        <input type="submit" id="save" value="Save changes" />    
    </form>

update.php

<?php
$data_to_write = $_POST['testdata'];
$file_path = 'test.txt';
$file_handle = fopen($file_path, 'w'); 
fwrite($file_handle, $data_to_write);
fclose($file_handle);
$myfile = fopen('test.txt', 'r');
 while(!feof($myfile)) {
          echo fgets($myfile);
    }
fclose($myfile);
?>

text.txt "lorem ipsum"