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javascript - jQuery Ajax File Upload

问题描述:

Can I use the following jQuery code to perform file upload using post method of an Ajax request ?

$.ajax({

type: "POST",

timeout: 50000,

url: url,

data: dataString,

success: function (data) {

alert('success');

return false;

}

});

If it is possible, do I need to fill "data" part? Is it the correct way? I only post the file to the server side.

I have been Googling around, but what I found was a plugin while in my plan I do not want to use it. At least for the moment.

网友答案:

file upload is not possible through ajax. You can upload file, without refreshing page by using IFrame. you can check further detail here

UPDATE:

With XHR2, File upload through AJAX is supported. E.g. through FormData object, but unfortunately it is not supported by all/old browsers.

FormData support starts from following desktop browsers versions. IE 10+, Firefox 4.0+, Chrome 7+, Safari 5+, Opera 12+

For more detail, see MDN link

网友答案:

Iframes is no longer needed for uploading files through ajax. I've recently done it by myself. Check out these pages:

Using HTML5 file uploads with AJAX and jQuery

http://dev.w3.org/2006/webapi/FileAPI/#FileReader-interface

$(':file').change(function(){
    var file = this.files[0];
    name = file.name;
    size = file.size;
    type = file.type;

    if(file.name.length < 1) {
    }
    else if(file.size > 100000) {
        alert("The file is too big");
    }
    else if(file.type != 'image/png' && file.type != 'image/jpg' && file.type != 'image/gif' && file.type != 'image/jpeg' ) {
        alert("The file does not match png, jpg or gif");
    }
    else { 
        $(':submit').click(function(){
            var formData = new FormData($('*formId*')[0]);
            $.ajax({
                url: 'script',  //server script to process data
                type: 'POST',
                xhr: function() {  // custom xhr
                    myXhr = $.ajaxSettings.xhr();
                    if(myXhr.upload){ // if upload property exists
                        myXhr.upload.addEventListener('progress', progressHandlingFunction, false); // progressbar
                    }
                    return myXhr;
                },
                // Ajax events
                success: completeHandler = function(data) {
                    /*
                    * Workaround for Chrome browser // Delete the fake path
                    */
                    if(navigator.userAgent.indexOf('Chrome')) {
                        var catchFile = $(":file").val().replace(/C:\\fakepath\\/i, '');
                    }
                    else {
                        var catchFile = $(":file").val();
                    }
                    var writeFile = $(":file");
                    writeFile.html(writer(catchFile));
                    $("*setIdOfImageInHiddenInput*").val(data.logo_id);
                },
                error: errorHandler = function() {
                    alert("Something went wrong!");
                },
                // Form data
                data: formData,
                // Options to tell jQuery not to process data or worry about the content-type
                cache: false,
                contentType: false,
                processData: false
            }, 'json');
        });
    }
});
网友答案:

Ajax post and upload file is possible. I'm using jQuery $.ajax function to load my files. I tried to use the XHR object but could not get results on the server side with PHP.

var formData = new FormData();
formData.append('file', $('#file')[0].files[0]);

$.ajax({
       url : 'upload.php',
       type : 'POST',
       data : formData,
       processData: false,  // tell jQuery not to process the data
       contentType: false,  // tell jQuery not to set contentType
       success : function(data) {
           console.log(data);
           alert(data);
       }
});

As you can see, you must create a FormData object, empty or from (serialized? - $('#yourForm').serialize()) existing form, and then attach the input file.

Here is more information: - How to upload a file using jQuery.ajax and FormData - Uploading files via jQuery, object FormData is provided and no file name, GET request

For the PHP process you can use something like this:

//print_r($_FILES);
$fileName = $_FILES['file']['name'];
$fileType = $_FILES['file']['type'];
$fileError = $_FILES['file']['error'];
$fileContent = file_get_contents($_FILES['file']['tmp_name']);

if($fileError == UPLOAD_ERR_OK){
   //Processes your file here
}else{
   switch($fileError){
     case UPLOAD_ERR_INI_SIZE:   
          $message = 'Error al intentar subir un archivo que excede el tamaño permitido.';
          break;
     case UPLOAD_ERR_FORM_SIZE:  
          $message = 'Error al intentar subir un archivo que excede el tamaño permitido.';
          break;
     case UPLOAD_ERR_PARTIAL:    
          $message = 'Error: no terminó la acción de subir el archivo.';
          break;
     case UPLOAD_ERR_NO_FILE:    
          $message = 'Error: ningún archivo fue subido.';
          break;
     case UPLOAD_ERR_NO_TMP_DIR: 
          $message = 'Error: servidor no configurado para carga de archivos.';
          break;
     case UPLOAD_ERR_CANT_WRITE: 
          $message= 'Error: posible falla al grabar el archivo.';
          break;
     case  UPLOAD_ERR_EXTENSION: 
          $message = 'Error: carga de archivo no completada.';
          break;
     default: $message = 'Error: carga de archivo no completada.';
              break;
    }
      echo json_encode(array(
               'error' => true,
               'message' => $message
            ));
}
网友答案:

I'm pretty late for this but I was looking for an ajax based image uploading solution and the answer I was looking for was kinda scattered throughout this post. The solution I settled on involved the FormData object. I assembled a basic form of the code I put together. You can see it demonstrates how to add a custom field to the form with fd.append() as well as how to handle response data when the ajax request is done.

Upload html:

<!DOCTYPE html>
<html>
<head>
    <title>Image Upload Form</title>
    <script src="//code.jquery.com/jquery-1.9.1.js"></script>
    <script type="text/javascript">
        function submitForm() {
            console.log("submit event");
            var fd = new FormData(document.getElementById("fileinfo"));
            fd.append("label", "WEBUPLOAD");
            $.ajax({
              url: "upload.php",
              type: "POST",
              data: fd,
              processData: false,  // tell jQuery not to process the data
              contentType: false   // tell jQuery not to set contentType
            }).done(function( data ) {
                console.log("PHP Output:");
                console.log( data );
            });
            return false;
        }
    </script>
</head>

<body>
    <form method="post" id="fileinfo" name="fileinfo" onsubmit="return submitForm();">
        <label>Select a file:</label><br>
        <input type="file" name="file" required />
        <input type="submit" value="Upload" />
    </form>
    <div id="output"></div>
</body>
</html>

In case you are working with php here's a way to handle the upload that includes making use of both of the custom fields demonstrated in the above html.

Upload.php

<?php
if ($_POST["label"]) {
    $label = $_POST["label"];
}
$allowedExts = array("gif", "jpeg", "jpg", "png");
$temp = explode(".", $_FILES["file"]["name"]);
$extension = end($temp);
if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/jpg")
|| ($_FILES["file"]["type"] == "image/pjpeg")
|| ($_FILES["file"]["type"] == "image/x-png")
|| ($_FILES["file"]["type"] == "image/png"))
&& ($_FILES["file"]["size"] < 200000)
&& in_array($extension, $allowedExts)) {
    if ($_FILES["file"]["error"] > 0) {
        echo "Return Code: " . $_FILES["file"]["error"] . "<br>";
    } else {
        $filename = $label.$_FILES["file"]["name"];
        echo "Upload: " . $_FILES["file"]["name"] . "<br>";
        echo "Type: " . $_FILES["file"]["type"] . "<br>";
        echo "Size: " . ($_FILES["file"]["size"] / 1024) . " kB<br>";
        echo "Temp file: " . $_FILES["file"]["tmp_name"] . "<br>";

        if (file_exists("uploads/" . $filename)) {
            echo $filename . " already exists. ";
        } else {
            move_uploaded_file($_FILES["file"]["tmp_name"],
            "uploads/" . $filename);
            echo "Stored in: " . "uploads/" . $filename;
        }
    }
} else {
    echo "Invalid file";
}
?>
网友答案:

Simple Upload Form

 <script>
   //form Submit action
   $("form").submit(function(evt){ 
      evt.preventDefault();
      var formData = new FormData($(this)[0]);
   $.ajax({
       url: 'fileUpload',
       type: 'POST',
       data: formData,
       async: false,
       cache: false,
       contentType: false,
       enctype: 'multipart/form-data',
       processData: false,
       success: function (response) {
         alert(response);
       }
   });
   return false;
 });
</script>
<form>
  <table>
    <tr>
      <td colspan="2">File Upload</td>
    </tr>
    <tr>
      <th>Select File </th>
      <td><input id="csv" name="csv" type="file" /></td>
    </tr>
    <tr>
      <td colspan="2">
        <input type="submit" value="submit"/> 
      </td>
    </tr>
  </table>
</form>
网友答案:

An AJAX upload is indeed possible with XMLHttpRequest(). No iframes necessary. Upload progress can be shown.

For details see: Answer http://stackoverflow.com/a/4943774/873282 to question jQuery Upload Progress and AJAX file upload.

网友答案:
  • Use a hidden iframe and set your form's target to that iframe's name. This way, when the form is submitted, only the iframe will be refreshed.
  • Have an event handler registered for the iframe's load event to parse the response.

More details on my blog post: http://blog.manki.in/2011/08/ajax-fie-upload.html.

网友答案:

In case you want to do it like that:

$.upload( form.action, new FormData( myForm))
.progress( function( progressEvent, upload) {
    if( progressEvent.lengthComputable) {
        var percent = Math.round( progressEvent.loaded * 100 / progressEvent.total) + '%';
        if( upload) {
            console.log( percent + ' uploaded');
        } else {
            console.log( percent + ' downloaded');
        }
    }
})
.done( function() {
    console.log( 'Finished upload');                    
});

than

https://github.com/lgersman/jquery.orangevolt-ampere/blob/master/src/jquery.upload.js

might be your solution.

网友答案:
$("#submit_car").click( function() {
  var formData = new FormData($('#car_cost_form')[0]);
$.ajax({
       url: 'car_costs.php',
       data: formData,
       async: false,
       contentType: false,
       processData: false,
       cache: false,
       type: 'POST',
       success: function(data)
       {
       },
     })    return false;    
});

edit: Note contentype and process data You can simply use this to upload files via Ajax...... submit input cannot be outside form element :)

网友答案:

I have implemented a multiple file select with instant preview and upload after removing unwanted files from preview via ajax.

Detailed documentation can be found here: 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;
}
网友答案:

You can use method ajaxSubmit as follow :) when you select a file that need upload to server, form be submit to server :)

$(document).ready(function () {
    var options = {
    target: '#output',   // target element(s) to be updated with server response
    timeout: 30000,
    error: function (jqXHR, textStatus) {
            $('#output').html('have any error');
            return false;
        }
    },
    success: afterSuccess,  // post-submit callback
    resetForm: true
            // reset the form after successful submit
};

$('#idOfInputFile').on('change', function () {
    $('#idOfForm').ajaxSubmit(options);
    // always return false to prevent standard browser submit and page navigation
    return false;
});
});
网友答案:

Yes you can, just use javascript to get the file, making sure you read the file as a data URL. Parse out the stuff before base64 to actually get the base 64 encoded data and then if you are using php or really any back end language you can decode the base 64 data and save into a file like shown below

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"]));

Of course you will probably want to do some validation like checking which file type you are dealing with and stuff like that but this is the idea.

网友答案:

If you want to upload file using AJAX here is code which you can use for file uploading.

$(document).ready(function() {
    var options = { 
                beforeSubmit:  showRequest,
        success:       showResponse,
        dataType: 'json' 
        }; 
    $('body').delegate('#image','change', function(){
        $('#upload').ajaxForm(options).submit();        
    }); 
});     
function showRequest(formData, jqForm, options) { 
    $("#validation-errors").hide().empty();
    $("#output").css('display','none');
    return true; 
} 
function showResponse(response, statusText, xhr, $form)  { 
    if(response.success == false)
    {
        var arr = response.errors;
        $.each(arr, function(index, value)
        {
            if (value.length != 0)
            {
                $("#validation-errors").append('<div class="alert alert-error"><strong>'+ value +'</strong><div>');
            }
        });
        $("#validation-errors").show();
    } else {
         $("#output").html("<img src='"+response.file+"' />");
         $("#output").css('display','block');
    }
}

Here is the HTML for Upload the file

<form class="form-horizontal" id="upload" enctype="multipart/form-data" method="post" action="upload/image'" autocomplete="off">
    <input type="file" name="image" id="image" /> 
</form>
网友答案:

Ajax does not support file uploads, you should use iframe instead

网友答案:

Here was an idea i was thinking of:

Have an iframe on page and have a referencer.

Have a form in which you move the INPUT:File element to.

Form:  A processing page AND a target of the FRAME.

The result will post to the frame, and then you can just send the fetched data up a level to the image tag you want with something like:

data:image/png;base64,asdfasdfasdfasdfa

and the page loads.

I believe it works for me, and depending you might be able to do something like:

.aftersubmit(function(){
    stopPropigation()// or some other code which would prevent a refresh.
});
网友答案:

I have handled these in a simple code. You can download a working demo from here

For your case, these very possible. I will take you step by step how you can upload a file to the server using AJAX jquery.

First let's us create an HTML file to add the following form file element as shown below.

<form action="" id="formContent" method="post" enctype="multipart/form-data" >
         <input  type="file" name="file"  required id="upload">
         <button class="submitI" >Upload Image</button> 
</form>

Secondly create a jquery.js file and add the following code to handle our file submission to the server

    $("#formContent").submit(function(e){
        e.preventDefault();

    var formdata = new FormData(this);

        $.ajax({
            url: "ajax_upload_image.php",
            type: "POST",
            data: formdata,
            mimeTypes:"multipart/form-data",
            contentType: false,
            cache: false,
            processData: false,
            success: function(){
                alert("file successfully submitted");
            },error: function(){
                alert("okey");
            }
         });
      });
    });

There you are done . View more

网友答案:

to upload a file which is submitted by user as a part of form using jquery please follow the below code :

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

Then send the form data object to server.

We can also append a File or Blob directly to the FormData object.

data.append("myfile", myBlob, "filename.txt");
网友答案:

To get all your form inputs, including the type="file" you need to use FormData object. you will be able to see the formData content in the debugger -> network ->Headers after you will submit the form.

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");
});
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