boards/static/js/form.js

var isCompact = true;

$('input[name=image]').wrap($('<div class="file_wrap"></div>'));

$('body').on('change', 'input[name=image]', function(event) {
    var file = event.target.files[0];

    if(file.type.match('image.*')) {
        var fileReader = new FileReader();

        fileReader.addEventListener("load", function(event) {
            var wrapper = $('.file_wrap');

            wrapper.find('.file-thumb').remove();
            wrapper.append(
                $('<div class="file-thumb" style="background-image: url('+event.target.result+')"></div>')
            );
        });

        fileReader.readAsDataURL(file);
    }
});

var compactForm = $('.swappable-form-compact');
var fullForm = $('.swappable-form-full');

function swapForm() {
    compactForm.toggle();
    fullForm.toggle();

    if (isCompact) {
        var oldText = compactForm.find('textarea')[0].value;
        fullForm.find('textarea')[0].value = oldText;
    } else {
        var oldText = fullForm.find('textarea')[0].value;
        compactForm.find('textarea')[0].value = oldText;
    }
    isCompact = !isCompact;
    
    scrollToBottom();
}

if (compactForm.length > 0) {
    fullForm.toggle();
}