Upload multiple image using AJAX, PHP and jQuery

Question

I have a lot of problem to upload multiple images using AJAX. I write this code:

HTML

<form id="upload" method="post" enctype="multipart/form-data">
    <div id="drop" class="drop-area">
        <div class="drop-area-label">
            Drop image here
        </div>
        <input type="file" name="file" id="file" multiple/>
    </div>

    <ul class="gallery-image-list" id="uploads">
    <!-- The file uploads will be shown here -->
    </ul>
</form>
<div id="listTable"></div>

jQuery/AJAX

$(document).on("change", "input[name^='file']", function(e){
    e.preventDefault();
    var This    =   this,
        display =   $("#uploads");

    // list all file data
    $.each(This.files, function(i, obj){
        // for each image run script asynchronous
        (function(i) {
            // get data from input file
            var file = This.files[i],
                name = file.name,
                size = file.size,
                type = file.type,
                lastModified        =   file.lastModified,
                lastModifiedDate    =   file.lastModifiedDate,
                webkitRelativePath  =   file.webkitRelativePath,
                slice               =   file.slice,
                i = i;

            // DEBUG
       /*
            var acc = []
            $.each(file, function(index, value) {
                acc.push(index + ": " + value);
            });
            alert(JSON.stringify(acc));
        */

            $.ajax({
                url:'/ajax/upload.php',
                contentType: "multipart/form-data",
                data:{
                        "image":
                        {
                            "name":name,
                            "size":size,
                            "type":type,
                            "lastModified":lastModified,
                            "lastModifiedDate":lastModifiedDate,
                            "webkitRelativePath":webkitRelativePath,
                            //"slice":slice,
                        }
                    },
                type: "POST",
                // Custom XMLHttpRequest
                xhr: function() {
                    var myXhr = $.ajaxSettings.xhr();
                    // Check if upload property exists
                    if(myXhr.upload)
                    {
                        // For handling the progress of the upload
                        myXhr.upload.addEventListener("progress",progressHandlingFunction, false); 
                    }
                    return myXhr;
                },
                cache: false,
                success : function(data){
                    // load ajax data
                    $("#listTable").append(data);
                }
            });
            // display progress
            function progressHandlingFunction(e){
                if(e.lengthComputable){
                    var perc = Math.round((e.loaded / e.total)*100);
                    perc = ( (perc >= 100) ? 100 : ( (perc <= 0) ? 0 : 0 ) );
                $("#progress"+i+" > div")
                    .attr({"aria-valuenow":perc})
                        .css("width", perc+"%");
                }
            }
            // display list of files
            display.append('<li>'+name+'</li><div class="progress" id="progress'+i+'">'
                    +'<div class="progress-bar" role="progressbar" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100" style="width: 0%;">'
                    +'</div></div>');
        })(i);
    }); 
});

I've tried a various versions and I never succeed to send multiple data through ajax. I have tried in this way what you see above, and now I get only POST informations. I understand why i get POST but I need to send FILES information and I do not know where I'm wrong.

I not work the first time with ajax and often use it for most projects but I have never used to send multiple files and that bothering me now.

Thanks!

Barbiturism

Please clarify: 1. contentType is multipart/form-data but data is not (jQuery.param will convert js object into x-www-form-urlencoded instead), so data will be lost in translation. What do you want to transfer and how? 2. Actual image data is not uploaded, is this intentional? 3. One ajax is called for each file, causing lots of connection and conflict in progress handler, is this intentional? 4. I do not see any drag drop code. Do you want it? – Vaginectomy

Answer 1

Try utilizing json to upload , process file object

html

<div id="drop" class="drop-area ui-widget-header">
  <div class="drop-area-label">Drop image here</div>
</div>
<br />
<form id="upload">
  <input type="file" name="file" id="file" multiple="true" accepts="image/*" />
  <ul class="gallery-image-list" id="uploads">
    <!-- The file uploads will be shown here -->
  </ul>
</form>
<div id="listTable"></div>

css

  #uploads {
      display:block;
      position:relative;
  } 

  #uploads li {
      list-style:none;
  }

  #drop {
      width: 90%;
      height: 100px;
      padding: 0.5em;
      float: left;
      margin: 10px;
      border: 8px dotted grey;
  }

  #drop.hover {
      border: 8px dotted green;
  }

  #drop.err {
      border: 8px dotted orangered;
  }

js

var display = $("#uploads"); // cache `#uploads`, `this` at `$.ajax()`
var droppable = $("#drop")[0]; // cache `#drop` selector
$.ajaxSetup({
    context: display,
    contentType: "application/json",
    dataType: "json",
    beforeSend: function (jqxhr, settings) {
        // pre-process `file`
        var file = JSON.parse(
                   decodeURIComponent(settings.data.split(/=/)[1])
                   );
        // add `progress` element for each `file`
        var progress = $("<progress />", {
                "class": "file-" + (!!$("progress").length 
                         ? $("progress").length 
                         : "0"),
                "min": 0,
                "max": 0,
                "value": 0,
                "data-name": file.name
        });
        this.append(progress, file.name + "<br />");
        jqxhr.name = progress.attr("class"); 
    }
});

var processFiles = function processFiles(event) {
    event.preventDefault();
    // process `input[type=file]`, `droppable` `file`
    var files = event.target.files || event.dataTransfer.files;
    var images = $.map(files, function (file, i) {
        var reader = new FileReader();
        var dfd = new $.Deferred();
        reader.onload = function (e) {
            dfd.resolveWith(file, [e.target.result])
        };
        reader.readAsDataURL(new Blob([file], {
            "type": file.type
        }));
        return dfd.then(function (data) {
            return $.ajax({
                type: "POST",
                url: "/echo/json/",
                data: {
                    "file": JSON.stringify({
                            "file": data,
                            "name": this.name,
                            "size": this.size,
                            "type": this.type
                    })
                },
                xhr: function () {
                    // do `progress` event stuff
                    var uploads = this.context;
                    var progress = this.context.find("progress:last");
                    var xhrUpload = $.ajaxSettings.xhr();
                    if (xhrUpload.upload) {
                        xhrUpload.upload.onprogress = function (evt) {
                            progress.attr({
                                    "max": evt.total,
                                    "value": evt.loaded
                            })
                        };
                        xhrUpload.upload.onloadend = function (evt) {
                            var progressData = progress.eq(-1);
                            console.log(progressData.data("name")
                                    + " upload complete...");
                            var img = new Image;
                            $(img).addClass(progressData.eq(-1)
                            .attr("class"));
                            img.onload = function () {
                                if (this.complete) {
                                  console.log(
                                      progressData.data("name")
                                      + " preview loading..."
                                  );
                                };

                            };
                        uploads.append("<br /><li>", img, "</li><br />");
                        };
                    }
                    return xhrUpload;
                }
            })
            .then(function (data, textStatus, jqxhr) {
                console.log(data)
                this.find("img[class=" + jqxhr.name + "]")
                .attr("src", data.file)
                .before("<span>" + data.name + "</span><br />");
                return data
            }, function (jqxhr, textStatus, errorThrown) {
                console.log(errorThrown);
                return errorThrown
            });
        })
    });
    $.when.apply(display, images).then(function () {
        var result = $.makeArray(arguments);
        console.log(result.length, "uploads complete");
    }, function err(jqxhr, textStatus, errorThrown) {
        console.log(jqxhr, textStatus, errorThrown)
    })
};

$(document)
.on("change", "input[name^=file]", processFiles);
// process `droppable` events
droppable.ondragover = function () {
    $(this).addClass("hover");
    return false;
};

droppable.ondragend = function () {
    $(this).removeClass("hover")
    return false;
};

droppable.ondrop = function (e) {
    $(this).removeClass("hover");
    var image = Array.prototype.slice.call(e.dataTransfer.files)
        .every(function (img, i) {
        return /^image/.test(img.type)
    });
    e.preventDefault();
    // if `file`, file type `image` , process `file`
    if (!!e.dataTransfer.files.length && image) {
            $(this).find(".drop-area-label")
            .css("color", "blue")
            .html(function (i, html) {
            $(this).delay(3000, "msg").queue("msg", function () {
                $(this).css("color", "initial").html(html)
            }).dequeue("msg");
            return "File dropped, processing file upload...";
        });
        processFiles(e);
    } else {
            // if dropped `file` _not_ `image`
            $(this)
            .removeClass("hover")
            .addClass("err")
            .find(".drop-area-label")
            .css("color", "darkred")
            .html(function (i, html) {
            $(this).delay(3000, "msg").queue("msg", function () {
                $(this).css("color", "initial").html(html)
                .parent("#drop").removeClass("err")
            }).dequeue("msg");
            return "Please drop image file...";
        });
    };
};

php

<?php
  if (isset($_POST["file"])) {
    // do php stuff
    // call `json_encode` on `file` object
    $file = json_encode($_POST["file"]);
    // return `file` as `json` string
    echo $file;
  };

jsfiddle http://jsfiddle.net/guest271314/0hm09yqo/

Unreeve

Question, in PHP, string $file I use for handling with data and can do upload like with $_FILE[] ? – Kliber

@IvijanStefanStipić You are welcome:) $file at php portion at post not same as $_FILES . $_FILES appear to require <form> element , with enctype="multipart/form-data" attribute. Approach at post utilizes JSON data type to post , process response. See php.net/manual/en/features.file-upload.post-method.php , w3.org/TR/html401/interact/forms.html#h-17.13.4.2 , sitepoint.com/handle-file-uploads-php , #3587419 . – Unreeve

I'm asking because I want to resize the image, rename, make thumb and save in folders. I'll look this links and try. Thanks again. – Kliber

@IvijanStefanStipić The actual image should be a data-uri developer.mozilla.org/en-US/docs/Web/HTTP/data_URIs at file.file , image name at file.name . – Unreeve