add more button dont work in wordpress dashboard

Question

im working on custom post in wordpress, in this custom post i wanna add many photos using wp_attachment the problem im having here is that when i click addmore nothing happen, its like if wordpress is ignoring my jquery file my code

<div class="col-sm-9">
            <input type="file" name="aduploadfiles[]" id="uploadfiles2" size="35" class="form-control" />         
            <input type="button" id="add_more2" class="upload" value="add more photo"/>
</div>

and this is the javascript im using

 var abc = 0; //Declaring and defining global increement variable

$(document).ready(function() {

//To add new input file field dynamically, on click of "Add More Files" button below function will be executed
    $('#add_more2').click(function() {
        $(this).before($("<div/>", {id: 'uploadfiles2'}).fadeIn('slow').append(
                $("<input/>", {name: 'aduploadfiles[]', type: 'file', id: 'aduploadfiles',size:'35', class:'form-control'})
                ));
    });

//following function will executes on change event of file input to select different file   
$('body').on('change', '#file', function(){
            if (this.files && this.files[0]) {
                 abc += 1; //increementing global variable by 1

                var z = abc - 1;
                var x = $(this).parent().find('#previewimg' + z).remove();
                $(this).before("<div id='abcd"+ abc +"' class='abcd'><img id='previewimg" + abc + "' src=''/></div>");

                var reader = new FileReader();
                reader.onload = imageIsLoaded;
                reader.readAsDataURL(this.files[0]);

                $(this).hide();
                $("#abcd"+ abc).append($("<img/>", {id: 'img', src: 'x.png', alt: 'delete'}).click(function() {
                $(this).parent().parent().remove();
                }));
            }
        });

//To preview image     
    function imageIsLoaded(e) {
        $('#previewimg' + abc).attr('src', e.target.result);
    };

    $('#upload').click(function(e) {
        var name = $(":file").val();
        if (!name)
        {
            alert("First Image Must Be Selected");
            e.preventDefault();
        }
    });
});

this works fine when i try it in a wordpress pages but in dashboard itdoesn't want to work even my javascript is loaded

score 3 · Accepted Answer · edited May 23 '17 at 10:33

There are several issues:

1. `$` is not available. Use `jQuery`

In WordPress, jQuery runs in compatibility mode, i.e. the $ shortcut is not available. You can solve this by capturing jQuery as function argument in the ready method, like this:

jQuery(document).ready(function($) {

The rest of the code in the ready callback can then continue to use $.

2. Wrong selector for file upload input element

You mentioned the wrong id in the jQuery selector: your file upload element has id uploadfiles2, not file. So change:

$('body').on('change', '#file', function(){

To:

$('body').on('change', '[name="aduploadfiles[]"]', function(){

3. Duplicate `id` values

Each time when you add a new button, you create a div with an id of uploadfiles2: but that id already exists. In HTML id values must be unique, otherwise unexpected things happen.

All the elements you create dynamically should get a dynamically created (distinct) id value (or no id at all).

thank you but thats not the problem, the code works fine when used on a normal page, its just that when used in wordpress dashboard it dont work, the error im getting in console is TypeError: $ is not a function addmore.js:3:1 — Messi Adrinho, Aug 27 '16 at 22:10

add more button dont work in wordpress dashboard

1 Answers1

1. $ is not available. Use jQuery

2. Wrong selector for file upload input element

3. Duplicate id values

1. `$` is not available. Use `jQuery`

3. Duplicate `id` values