How to show upload image preview using jquery before form submit in a div

Question

I am dealing with a form that contains various form elements with an option to upload multiple images(upto 6 max). Now i am having a div preview on clicking that div i fetch all form fields using jquery (form still not submitted at this time as its a multi form step1, 2 and 3). Now the problem is that i am fetching all form data with this code -

var allFormData = $("#myform").serializeArray(); 

Using this another code i am able to show rest of the data in div, but image is not coming.

$.each(adtitletoshow, function(i, field){
    if( field.name == 'desc'){ 
        $(".add_desc").text(field.value);
    }
});

This is the filed created by JS to upload image.

<script type="text/javascript">
    var total_images = 1 ;
    function add_file_field () {
        total_images++ ;
        if ( total_images > 6 ) return ;
        var str_to_embed = '<input name="fileImage[]" size="40" style="width: 500px;" type="file" onChange="add_file_field()"><br>' ;
        $("#image_stack").append ( str_to_embed ) ;
    }
</script>

All things going on single page so i need a solution that how can i load images under my preview div. Let me know if thr is some point of ambiguity still persists.

Solution 1

You need to loop through the files array from the multiple input and use the FileReader API on each.

I've set up the HTML like this:

​<input type="file" multiple="true" id="files" />
<input type="submit" id="go"/>
<div id="images"></div>​​​​​​​​​​​​​​​​​​​​​​

Then the javascript as follows:

// set up variables
var reader = new FileReader(),
    i=0,
    numFiles = 0,
    imageFiles;

// use the FileReader to read image i
function readFile() {
    reader.readAsDataURL(imageFiles[i])
}

// define function to be run when the File
// reader has finished reading the file
reader.onloadend = function(e) {

    // make an image and append it to the div
    var image = $('<img>').attr('src', e.target.result);
    $(image).appendTo('#images');

    // if there are more files run the file reader again
    if (i < numFiles) {
        i++;
        readFile();
    }
};

$('#go').click(function() {

    imageFiles = document.getElementById('files').files
    // get the number of files
    numFiles = imageFiles.length;
    readFile();           

});

I've set up a JSFiddle to demo http://jsfiddle.net/3LB72/

You'll probably want to do more checks on whether the browser the user is using has FileReader and if the files they have chosen are image files.

Solution 2

JSFiddle demo

This is much better, without clicking any button :D

HTML:

<input type="file" multiple="true" id="files" />
<input type="submit" id="go"/>
<div id="images"></div>

JavaScript:

// set up variables
var reader = new FileReader(),
    i=0,
    numFiles = 0,
    imageFiles;

// use the FileReader to read image i
function readFile() {
    reader.readAsDataURL(imageFiles[i])
}

// define function to be run when the File
// reader has finished reading the file
reader.onloadend = function(e) {

// make an image and append it to the div
$("#images").css({'background-image':'url('+e.target.result+')'});    
    // if there are more files run the file reader again
    if (i < numFiles) {
        i++;
        readFile();
    }
};

$('#files').live('change', function(){
    imageFiles = document.getElementById('files').files
    // get the number of files
    numFiles = imageFiles.length;
    readFile();           
});