图像上传前有多个缩略图

Question

I am very unexperienced in Javascript/Jquery therefore I use the JavaScript Load Image plugin to handle the front end of my image upload process.

The Problem:
I would like to upload multiple images , not just one, and therefore also would like to display all the images, which are to be uploaded as a thumbnail . At the moment just one image is shown as a thumbnail.


The Fiddle: https://jsfiddle.net/r7s3n64b/1/ (displaying just one thumbnail)


HTML (the relevant parts)

<!-- FILE INPUT -->
<p><input type="file" name="images[]" id="upload-post-images" multiple></p>

<!-- THUMBNAILS -->
<div id="result" class="result">
    <p>This only works in browsers with support for the <a href="https://developer.mozilla.org/en/DOM/window.URL">URL</a> or <a href="https://developer.mozilla.org/en/DOM/FileReader">FileReader</a> API.</p>
</div><br>

My attempt to loop through the to be uploaded images:

replaceResults = function (img) {
        var content;
        var imageFiles = document.getElementById("upload-post-images"),
        filesLength = imageFiles.files.length;

        // Loop through the FileList and render image files as thumbnails.
        for (var i = 0; i < filesLength; i++) {
            if (!(img.src || img instanceof HTMLCanvasElement)) {
                content = $('<span>Die Bilddatei konnte nicht geladen werden.</span>');
            } else {
                content = $('<a target="_blank">').append(img)
                    .attr('download', currentFile.name)
                    .attr('href', img.src || img.toDataURL());
            }
            result.children().replaceWith(content);
            if (img.getContext) {
                actionsNode.show();
            }
        } // end for loop
    },

I would be very thankful for any kind of help!!

=== EDIT ===

In your fiddle the thumbnails are placed after the closing form tag:

 </form>
 <img src="blob:https%3A//fiddle.jshell.net/001bd1f5-1cce-4618-bc83-9c8bd24f9e90" width="200" height="150">
 <img src="blob:https%3A//fiddle.jshell.net/001bd1f5-1cce-4618-bc83-9c8bd24f9e90" width="200" height="150">

In my project (using your code) the thumbnail is placed within the result div:

<div id="result" class="result">
    <a target="_blank" download="image.jpg" href="data:image/png;base64,iVBO3sSxiFIz6LUNoB9b27d/p9/HzNSojY7M+FCmPOnGAsrVBWlKSGsSfG4GBNOzbIWtW38xtqwSLsTpzHF7/N4n7PwQgrIo5fh...></a>
    <canvas width="265" height="354"></canvas>
</div>

Is there any chance that you would happen to have an idea why this is or how I could change that?!

Thank you so much for your tremendous help!

Answer 1

You need to change your on change function to this:

document.getElementById('upload-post-images').onchange = function (e) {
    for(i = 0; i<=e.target.files.length; i++)
    {
       loadImage(
          e.target.files[i],
          function (img) {
              document.body.appendChild(img);
          },
          {maxWidth: 200} // Options
       );
    }
};

Here is updated jsFiddle: https://jsfiddle.net/r7s3n64b/2/

Earlier your event handler looked like this:

document.getElementById('upload-post-images').onchange = function (e) {
    loadImage(
        e.target.files[0],
        function (img) {
            document.body.appendChild(img);
        },
        {maxWidth: 200} // Options
    );
};

So beacuse of this line:

e.target.files[0]

You always pass only one image (first) from image array.

Enjoy! :)

UPDATE

Regarding your update - so basically it's all about the second parameter in loadImage function.

Answer 2

Change your upload-post-images change event like following.

document.getElementById('upload-post-images').onchange = function (e) {
    $.each(e.target.files, function () {
        loadImage(
          this,
          function (img) {
              document.body.appendChild(img);
          }, {
              maxWidth: 200
          } // Options
        )
    });
};

UPDATED FIDDLE