JS: pass variable onclick

Question

I'm trying to pass a variable to a function, I know there are many topics about this, and I've nearly tried all suggestions, but still can't get it to work, these are my attempts:

edit: without the onclick, everything is working fine

var filename = file.name;

<button class="btn btn-danger delete" onclick="deleteImage(\''+filename+'\');">

results in: Uncaught SyntaxError: Unexpected token ILLEGAL

<button class="btn btn-danger delete" onclick="deleteImage(&quot;'+type+'&quot;);">

results in (alert): 'filename'

<button class="btn btn-danger delete" onclick="deleteImage('" + filename + "');">

results in: Uncaught SyntaxError: Unexpected token ILLEGAL

<button class="btn btn-danger delete" onclick="deleteImage(" + filename + ");">

result in: Uncaught SyntaxError: Unexpected token }

this is the full code (modified, blueimp fileuploader)

    <script id="template-download" type="text/x-tmpl">
{% for (var i=0, file; file=o.files[i]; i++) { %}
    <tr class="template-download fade">
        {% if (file.error) { %}
            <td></td>
            <td class="name"><span>{%=file.name%}</span></td>
            <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>
            <td class="error" colspan="2"><span class="label label-important">Error</span> {%=file.error%}</td>
        {% } else { 
            // add the image urls to the file inputbox
            var filename = file.name;
            var prev = $("#mFile").val(); 
            $("#mFile").val(prev + file.name + ","); 

            %}
            <td class="preview">{% if (file.thumbnail_url) { %}
                <a href="modules/mod_stern_form_prijsopgave/upload/server/php/files/{%=file.name%}" title="{%=file.name%}" data-gallery="gallery" download="{%=file.name%}"><img src="modules/mod_stern_form_prijsopgave/upload/server/php/files/thumbnail/{%=file.name%}"></a>
            {% } %}</td>
            <td class="name">
                <a href="modules/mod_stern_form_prijsopgave/upload/server/php/files/{%=file.name%}" title="{%=file.name%}" data-gallery="{%=file.thumbnail_url&&'gallery'%}" download="{%=file.name%}">{%=file.name%}</a>
            </td>
            <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>
            <td colspan="2"></td>
        {% } %}
        <td>
            <button class="btn btn-danger delete" onclick="deleteImage('" + filename + "');" data-type="{%=file.delete_type%}" data-url="{%=file.delete_url%}"{% if (file.delete_with_credentials) { %} data-xhr-fields='{"withCredentials":true}'{% } %}>
                <i class="icon-trash icon-white"></i>
                <span>Verwijderen</span>
            </button>
        </td>
    </tr>
{% } %}
</script>

and testing like this:

    function deleteImage(filename) {
      alert(filename);
    }

what am I doing wrong? Thanks for your advice

Answer 1

<button id="deleteOnClick" class="btn btn-danger delete">...</button>

and in javascript:

document.getElementById("deleteOnClick").onclick = function(){deleteImage(filename);}

edit:

if you want to delete the file specified only by the original filename value:

var deleteByFile = (function (filename){
    return function(){deleteImage(filename);};
}(filename));
document.getElementById("deleteOnClick").onclick = deleteByFile