Sending multipart/formdata with jQuery.ajax

I've got a problem sending a file to a serverside PHP-script using jQuery's ajax-function. It's possible to get the File-List with $('#fileinput').attr('files') but how is it possible to send this Data to the server? The resulting array ( $_POST ) on the serverside php-script is 0 ( NULL ) when using the file-input.

I know it is possible (though I didn't find any jQuery solutions until now, only Prototye code (http://webreflection.blogspot.com/2009/03/safari-4-multiple-upload-with-progress.html)).

This seems to be relatively new, so please do not mention file upload would be impossible via XHR/Ajax, because it's definitely working.

I need the functionality in Safari 5, FF and Chrome would be nice but are not essential.

My code for now is:

$.ajax({
    url: 'php/upload.php',
    data: $('#file').attr('files'),
    cache: false,
    contentType: 'multipart/form-data',
    processData: false,
    type: 'POST',
    success: function(data){
        alert(data);
    }
});

Starting with Safari 5/Firefox 4, it's easiest to use the FormData class:

var data = new FormData();
jQuery.each(jQuery('#file')[0].files, function(i, file) {
    data.append('file-'+i, file);
});

So now you have a FormData object, ready to be sent along with the XMLHttpRequest.

jQuery.ajax({
    url: 'php/upload.php',
    data: data,
    cache: false,
    contentType: false,
    processData: false,
    method: 'POST',
    type: 'POST', // For jQuery < 1.9
    success: function(data){
        alert(data);
    }
});

It's imperative that you set the contentType option to false , forcing jQuery not to add a Content-Type header for you, otherwise, the boundary string will be missing from it. Also, you must leave the processData flag set to false, otherwise, jQuery will try to convert your FormData into a string, which will fail.

You may now retrieve the file in PHP using:

$_FILES['file-0']

(There is only one file, file-0 , unless you specified the multiple attribute on your file input, in which case, the numbers will increment with each file.)

Using the FormData emulation for older browsers

var opts = {
    url: 'php/upload.php',
    data: data,
    cache: false,
    contentType: false,
    processData: false,
    method: 'POST',
    type: 'POST', // For jQuery < 1.9
    success: function(data){
        alert(data);
    }
};
if(data.fake) {
    // Make sure no text encoding stuff is done by xhr
    opts.xhr = function() { var xhr = jQuery.ajaxSettings.xhr(); xhr.send = xhr.sendAsBinary; return xhr; }
    opts.contentType = "multipart/form-data; boundary="+data.boundary;
    opts.data = data.toString();
}
jQuery.ajax(opts);

Create FormData from an existing form

Instead of manually iterating the files, the FormData object can also be created with the contents of an existing form object:

var data = new FormData(jQuery('form')[0]);

Use a PHP native array instead of a counter

Just name your file elements the same and end the name in brackets:

jQuery.each(jQuery('#file')[0].files, function(i, file) {
    data.append('file[]', file);
});

$_FILES['file'] will then be an array containing the file upload fields for every file uploaded. I actually recommend this over my initial solution as it's simpler to iterate over.


I've just build this function based on some info I read.

Use it like using .serialize() , instead just put .serializefiles(); .
Working here in my tests.

//USAGE: $("#form").serializefiles();
(function($) {
$.fn.serializefiles = function() {
    var obj = $(this);
    /* ADD FILE TO PARAM AJAX */
    var formData = new FormData();
    $.each($(obj).find("input[type='file']"), function(i, tag) {
        $.each($(tag)[0].files, function(i, file) {
            formData.append(tag.name, file);
        });
    });
    var params = $(obj).serializeArray();
    $.each(params, function (i, val) {
        formData.append(val.name, val.value);
    });
    return formData;
};
})(jQuery);

Just wanted to add a bit to Raphael's great answer. Here's how to get PHP to produce the same $_FILES , regardless of whether you use JavaScript to submit.

HTML form:

<form enctype="multipart/form-data" action="/test.php" 
method="post" class="putImages">
   <input name="media[]" type="file" multiple/>
   <input class="button" type="submit" alt="Upload" value="Upload" />
</form>

PHP produces this $_FILES , when submitted without JavaScript:

Array
(
    [media] => Array
        (
            [name] => Array
                (
                    [0] => Galata_Tower.jpg
                    [1] => 518f.jpg
                )

            [type] => Array
                (
                    [0] => image/jpeg
                    [1] => image/jpeg
                )

            [tmp_name] => Array
                (
                    [0] => /tmp/phpIQaOYo
                    [1] => /tmp/phpJQaOYo
                )

            [error] => Array
                (
                    [0] => 0
                    [1] => 0
                )

            [size] => Array
                (
                    [0] => 258004
                    [1] => 127884
                )

        )

)

If you do progressive enhancement, using Raphael's JS to submit the files...

var data = new FormData($('input[name^="media"]'));     
jQuery.each($('input[name^="media"]')[0].files, function(i, file) {
    data.append(i, file);
});

$.ajax({
    type: ppiFormMethod,
    data: data,
    url: ppiFormActionURL,
    cache: false,
    contentType: false,
    processData: false,
    success: function(data){
        alert(data);
    }
});

... this is what PHP's $_FILES array looks like, after using that JavaScript to submit:

Array
(
    [0] => Array
        (
            [name] => Galata_Tower.jpg
            [type] => image/jpeg
            [tmp_name] => /tmp/phpAQaOYo
            [error] => 0
            [size] => 258004
        )

    [1] => Array
        (
            [name] => 518f.jpg
            [type] => image/jpeg
            [tmp_name] => /tmp/phpBQaOYo
            [error] => 0
            [size] => 127884
        )

)

That's a nice array, and actually what some people transform $_FILES into, but I find it's useful to work with the same $_FILES , regardless if JavaScript was used to submit. So, here are some minor changes to the JS:

// match anything not a [ or ]
regexp = /^[^[]]+/;
var fileInput = $('.putImages input[type="file"]');
var fileInputName = regexp.exec( fileInput.attr('name') );

// make files available
var data = new FormData();
jQuery.each($(fileInput)[0].files, function(i, file) {
    data.append(fileInputName+'['+i+']', file);
});

(14 April 2017 edit: I removed the form element from the constructor of FormData() -- that fixed this code in Safari.)

That code does two things.

  • Retrieves the input name attribute automatically, making the HTML more maintainable. Now, as long as form has the class putImages, everything else is taken care of automatically. That is, the input need not have any special name.
  • The array format that normal HTML submits is recreated by the JavaScript in the data.append line. Note the brackets.
  • With these changes, submitting with JavaScript now produces precisely the same $_FILES array as submitting with simple HTML.

    链接地址: http://www.djcxy.com/p/19590.html

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