jQuery Ajax Datei-Upload

Question

Kann ich den folgenden jQuery-Code verwenden, um Datei-Upload mit POST-Methode einer Ajax-Anfrage durchzuführen?

$.ajax({
    type: "POST",
    timeout: 50000,
    url: url,
    data: dataString,
    success: function (data) {
        alert('success');
        return false;
    }
});

Wenn dies möglich ist, muss ich dann die data Teil? Ist das der richtige Weg? Ich POSTe die Datei nur an die Serverseite.

Ich habe herumgegoogelt, aber was ich gefunden habe, war ein Plugin, während ich es in meinem Plan nicht verwenden möchte. Zumindest für den Moment.

Answer 1

Ich habe eine Mehrfach-Dateiauswahl mit sofortiger Vorschau und Upload nach dem Entfernen unerwünschter Dateien aus der Vorschau über Ajax implementiert.

Eine ausführliche Dokumentation finden Sie hier: http://anasthecoder.blogspot.ae/2014/12/multi-file-select-preview-without.html

Demo: http://jsfiddle.net/anas/6v8Kz/7/embedded/result/

jsFiddle: http://jsfiddle.net/anas/6v8Kz/7/

Javascript:

    $(document).ready(function(){
    $('form').submit(function(ev){
        $('.overlay').show();
        $(window).scrollTop(0);
        return upload_images_selected(ev, ev.target);
    })
})
function add_new_file_uploader(addBtn) {
    var currentRow = $(addBtn).parent().parent();
    var newRow = $(currentRow).clone();
    $(newRow).find('.previewImage, .imagePreviewTable').hide();
    $(newRow).find('.removeButton').show();
    $(newRow).find('table.imagePreviewTable').find('tr').remove();
    $(newRow).find('input.multipleImageFileInput').val('');
    $(addBtn).parent().parent().parent().append(newRow);
}

function remove_file_uploader(removeBtn) {
    $(removeBtn).parent().parent().remove();
}

function show_image_preview(file_selector) {
    //files selected using current file selector
    var files = file_selector.files;
    //Container of image previews
    var imageContainer = $(file_selector).next('table.imagePreviewTable');
    //Number of images selected
    var number_of_images = files.length;
    //Build image preview row
    var imagePreviewRow = $('<tr class="imagePreviewRow_0"><td valign=top style="width: 510px;"></td>' +
        '<td valign=top><input type="button" value="X" title="Remove Image" class="removeImageButton" imageIndex="0" onclick="remove_selected_image(this)" /></td>' +
        '</tr> ');
    //Add image preview row
    $(imageContainer).html(imagePreviewRow);
    if (number_of_images > 1) {
        for (var i =1; i<number_of_images; i++) {
            /**
             *Generate class name of the respective image container appending index of selected images, 
             *sothat we can match images selected and the one which is previewed
             */
            var newImagePreviewRow = $(imagePreviewRow).clone().removeClass('imagePreviewRow_0').addClass('imagePreviewRow_'+i);
            $(newImagePreviewRow).find('input[type="button"]').attr('imageIndex', i);
            $(imageContainer).append(newImagePreviewRow);
        }
    }
    for (var i = 0; i < files.length; i++) {
        var file = files[i];
        /**
         * Allow only images
         */
        var imageType = /image.*/;
        if (!file.type.match(imageType)) {
          continue;
        }

        /**
         * Create an image dom object dynamically
         */
        var img = document.createElement("img");

        /**
         * Get preview area of the image
         */
        var preview = $(imageContainer).find('tr.imagePreviewRow_'+i).find('td:first');

        /**
         * Append preview of selected image to the corresponding container
         */
        preview.append(img); 

        /**
         * Set style of appended preview(Can be done via css also)
         */
        preview.find('img').addClass('previewImage').css({'max-width': '500px', 'max-height': '500px'});

        /**
         * Initialize file reader
         */
        var reader = new FileReader();
        /**
         * Onload event of file reader assign target image to the preview
         */
        reader.onload = (function(aImg) { return function(e) { aImg.src = e.target.result; }; })(img);
        /**
         * Initiate read
         */
        reader.readAsDataURL(file);
    }
    /**
     * Show preview
     */
    $(imageContainer).show();
}

function remove_selected_image(close_button)
{
    /**
     * Remove this image from preview
     */
    var imageIndex = $(close_button).attr('imageindex');
    $(close_button).parents('.imagePreviewRow_' + imageIndex).remove();
}

function upload_images_selected(event, formObj)
{
    event.preventDefault();
    //Get number of images
    var imageCount = $('.previewImage').length;
    //Get all multi select inputs
    var fileInputs = document.querySelectorAll('.multipleImageFileInput');
    //Url where the image is to be uploaded
    var url= "/upload-directory/";
    //Get number of inputs
    var number_of_inputs = $(fileInputs).length; 
    var inputCount = 0;

    //Iterate through each file selector input
    $(fileInputs).each(function(index, input){

        fileList = input.files;
        // Create a new FormData object.
        var formData = new FormData();
        //Extra parameters can be added to the form data object
        formData.append('bulk_upload', '1');
        formData.append('username', $('input[name="username"]').val());
        //Iterate throug each images selected by each file selector and find if the image is present in the preview
        for (var i = 0; i < fileList.length; i++) {
            if ($(input).next('.imagePreviewTable').find('.imagePreviewRow_'+i).length != 0) {
                var file = fileList[i];
                // Check the file type.
                if (!file.type.match('image.*')) {
                    continue;
                }
                // Add the file to the request.
                formData.append('image_uploader_multiple[' +(inputCount++)+ ']', file, file.name);
            }
        }
        // Set up the request.
        var xhr = new XMLHttpRequest();
        xhr.open('POST', url, true);
        xhr.onload = function () {
            if (xhr.status === 200) {
                var jsonResponse = JSON.parse(xhr.responseText);
                if (jsonResponse.status == 1) {
                    $(jsonResponse.file_info).each(function(){
                        //Iterate through response and find data corresponding to each file uploaded
                        var uploaded_file_name = this.original;
                        var saved_file_name = this.target;
                        var file_name_input = '<input type="hidden" class="image_name" name="image_names[]" value="' +saved_file_name+ '" />';
                        file_info_container.append(file_name_input);

                        imageCount--;
                    })
                    //Decrement count of inputs to find all images selected by all multi select are uploaded
                    number_of_inputs--;
                    if(number_of_inputs == 0) {
                        //All images selected by each file selector is uploaded
                        //Do necessary acteion post upload
                        $('.overlay').hide();
                    }
                } else {
                    if (typeof jsonResponse.error_field_name != 'undefined') {
                        //Do appropriate error action
                    } else {
                        alert(jsonResponse.message);
                    }
                    $('.overlay').hide();
                    event.preventDefault();
                    return false;
                }
            } else {
                /*alert('Something went wrong!');*/
                $('.overlay').hide();
                event.preventDefault();
            }
        };
        xhr.send(formData);
    })

    return false;
}

Answer 2

Um alle Formulareingaben zu erhalten, einschließlich der type="file" müssen Sie FormData-Objekt . können Sie den Inhalt von formData in der Spalte Debugger -> Netzwerk ->Kopfzeilen nachdem Sie das Formular abgeschickt haben.

var url = "YOUR_URL";

var form = $('#YOUR_FORM_ID')[0];
var formData = new FormData(form);

$.ajax(url, {
    method: 'post',
    processData: false,
    contentType: false,
    data: formData
}).done(function(data){
    if (data.success){ 
        alert("Files uploaded");
    } else {
        alert("Error while uploading the files");
    }
}).fail(function(data){
    console.log(data);
    alert("Error while uploading the files");
});

Answer 3

<html>
    <head>
        <title>Ajax file upload</title>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
        <script>
            $(document).ready(function (e) {
            $("#uploadimage").on('submit', (function(e) {
            e.preventDefault();
                    $.ajax({
                    url: "upload.php", // Url to which the request is send
                            type: "POST", // Type of request to be send, called as method
                            data: new FormData(this), // Data sent to server, a set of key/value pairs (i.e. form fields and values)
                            contentType: false, // The content type used when sending data to the server.
                            cache: false, // To unable request pages to be cached
                            processData:false, // To send DOMDocument or non processed data file it is set to false
                            success: function(data)   // A function to be called if request succeeds
                            {
                            alert(data);
                            }
                    });
            }));
        </script>
    </head>
    <body>
        <div class="main">
            <h1>Ajax Image Upload</h1><br/>
            <hr>
            <form id="uploadimage" action="" method="post" enctype="multipart/form-data">
                <div id="image_preview"><img id="previewing" src="noimage.png" /></div>
                <hr id="line">
                <div id="selectImage">
                    <label>Select Your Image</label><br/>
                    <input type="file" name="file" id="file" required />
                    <input type="submit" value="Upload" class="submit" />
                </div>
            </form>
        </div>
    </body>
</html>

Answer 4

Ja, Sie können, verwenden Sie einfach Javascript, um die Datei zu erhalten, stellen Sie sicher, dass Sie die Datei als Daten-URL zu lesen. Parsen Sie das Zeug vor base64, um die Base 64 kodierten Daten zu erhalten, und wenn Sie dann php oder eine andere Backend-Sprache verwenden, können Sie die Base 64-Daten dekodieren und in einer Datei wie unten gezeigt speichern

Javascript:
var reader = new FileReader();
reader.onloadend = function ()
{
  dataToBeSent = reader.result.split("base64,")[1];
  $.post(url, {data:dataToBeSent});
}
reader.readAsDataURL(this.files[0]);

PHP:
    file_put_contents('my.pdf', base64_decode($_POST["data"]));

Natürlich werden Sie wahrscheinlich einige Validierungen vornehmen wollen, wie z. B. die Überprüfung des Dateityps, mit dem Sie es zu tun haben, und ähnliches, aber das ist die Idee.

Answer 5

Zum Hochladen einer Datei, die vom Benutzer als Teil des Formulars mit Jquery eingereicht wird, folgen Sie bitte dem unten stehenden Code:

var formData = new FormData();
formData.append("userfile", fileInputElement.files[0]);

Senden Sie dann das Formular-Datenobjekt an den Server.

Wir können auch eine Datei oder einen Blob direkt an das FormData-Objekt anhängen.

data.append("myfile", myBlob, "filename.txt");