使用PHP将链接的动态href分配给另一个链接

Question

I have this problem. On my website I want to show the content of a folder with links. And if I click this link i want it to assign the source of the file to another link/button. So if I click the download button it downloads the file I clicked on.

this is what i got to show the files as links:

PHP

<?php
$path = "./files";

$dir_handle = @opendir($path) or die("Unable to open $path");

while ($file = readdir($dir_handle)) {
  if($file == "." || $file == ".." || $file == "index.php" )
  continue;
    echo "<a href=\"".$path."/".$file."\">$file</a><br />";
}

closedir($dir_handle);
?>

so this makes a link of every file in the folder but I cant figure out how to assign the source of the file I click on to a download button/link. Atleast I don't know a way that doesn't make a download link for every file.

Answer 1

Try this and note that this may not work depending on server and php settings. I am assuming you are using properly configured Apache (or Apache-comparable) server:

<?php

// Get the document root the server or virtual host is pointing to
$docroot = $_SERVER['DOCUMENT_ROOT'];
$docrootLen = strlen($docroot);

// realpath to get the full/expanded path to the files directly
$path = realpath('./files');

$dir_handle = @opendir($path) or die("Unable to open $path");

while ($file = readdir($dir_handle)) {
    if($file == "." || $file == ".." || $file == "index.php" )
        continue;

    // Create fileUrl by removing $docroot from the beginning of $path
    $fileUrl = substr($path, strpos($path, $docroot) + $docrootLen) . '/' . $file;

    echo '<a href="' . $fileUrl . '">', $file, '</a><br />';
}

?><a id="download-button"></a><?php

closedir($dir_handle);

For the "another link" part, notice I added an extra anchor tag above with the ID "download-button". This will be the download button. At the end of your HTML (before the closing body tag), you can add this script inside a <script> tag:

var links = document.getElementsByTagName("a"), linkIdx;
for( linkIdx in links ) {
    if( links[linkIdx].getAttribute("id") == "download-button" ) {
        // These are not the anchor tags you are looking for...
        continue;
    }
    links[linkIdx].addEventListener("click", function(e){
        // When the user clicks the link, don't allow the browser go to the link:
        e.preventDefault();
        document.getElementById("download-button").setAttribute("href", this.getAttribute("href"));
        document.getElementById("download-button").innerHTML = this.innerHTML;
    });
}