Question

我在jquery和ajax方面不是很有经验，但我需要以下内容。用户成功登录后，可以从页面下载pdf文件。该网站有一个崩溃div，他们可以从中选择要下载的文件。一切都在PHP完成，工作正常。但是，如果找不到该文件，则会关闭折叠div。换句话说，网页被重新加载。因此，用户必须重新进行新的选择，这是不方便的。所以我会这样做。如果找不到该文件，那么div应该保持折叠状态，并且输入字段中的前一个值应该是＆＃39; s＆＃39;在表格上。我知道这应该通过jquery或javascript来完成。我尝试过以下但是没有用。

         //PHP

  <?php
    //if download is clicked
     if (isset($_POST["download"])) {
    $data = $_POST["s"];

     //if file is found
     if (fileexists($data){
    // We'll be outputting a PDF 
    header('Content-type: application/pdf'); 

    // It will be called downloaded.pdf 
    header('Content-Disposition: attachment; filename="downloaded.pdf"'); 

    // The PDF source is in original.pdf 
    readfile($data); 
    }
    //else the div should remain open
    else{  
         echo "<script> if ($('#collapseOne').is(':hidden')) {
               $('#collapseOne').show();
              }</script>";
     }
   } 
     ?>              

         <div id="collapseOne" class="panel-collapse collapse">
            <div class="panel-body">
                <form id='searchForm' method="post" action=''>
                <p><label>Select Month</label></p>
                <input id='s' name = 's' type='text' required><br><br>
                <button type="submit" id='download' name='download' class='btn btn-default btn-lg'>
                    <span class='glyphicon glyphicon-download-alt'></span> Download
                </button>
                <br> <br>
                <button id='download1' name = 'download1' class='btn btn-default btn-lg'>
                    <span class='glyphicon glyphicon-download-alt'></span> Download All
                </button>
               </form>              
              </div>
        </div>

Answer 1

尝试使用它！

$.ajax({
    url:"/path/to/your/script/",
    type: "post",
    data: //fetch the data which you want to pass
}).done(function(status){
    //status is the data returned from the script called
});

Answer 2

简而言之，您将PHP回复到Javascript

<script> 
    $(document).ready(function(){
        var hasDownload = "<?php echo $_POST['download']; ?>";
        var oldInput = "<?php echo $_POST['s']; ?>";
        if(hasDownload == false) {
           $('#collapseOne').show();
           $('input#s').val(oldInput);
        }
    })        
</script>

当服务器为您的文件提供服务时，这些值将出现在您的Javascript中。把你的jQuery放在另一个if语句的底部。一个doc ready块，以便首先加载dom并将PHP变量回显到Javascript变量中以执行jQuery逻辑。

<?php

    if (isset($_POST["download"]) && fileexists($_POST["s"]) {
        header('Content-type: application/pdf'); 
        header('Content-Disposition: attachment; filename="downloaded.pdf"'); 
        readfile($_POST["s"]); 

    } 

?>              

<div id="collapseOne" class="panel-collapse collapse">
    <div class="panel-body">
        <form id='searchForm' method="post" action=''>
            <p><label>Select Month</label></p>
            <input id='s' name = 's' type='text' required><br><br>
            <button type="submit" id='download' name='download' class='btn btn-default btn-lg'>
                <span class='glyphicon glyphicon-download-alt'></span> Download
            </button>
            <br> <br>
            <button id='download1' name = 'download1' class='btn btn-default btn-lg'>
                <span class='glyphicon glyphicon-download-alt'></span> Download All
            </button>
       </form>              
    </div>
</div>

<?php if(isset($_POST["download"]) == false && fileexists($_POST["s"] == false) : ?>  
    <script> 
        $(document).ready(function(){
            var hasDownload = "<?php echo $_POST['download']; ?>";
            var oldInput = "<?php echo $_POST['s']; ?>";
            if(hasDownload == false) {
               $('#collapseOne').show();
               $('input#s').val(oldInput);
            }
        })        
    </script>
<?php endif; ?>

在php post方法中使用jquery

2 个答案: