21

I am developing a Rails app with a module for dynamic - ajax - image upload to gallery. I am doing it basing on this app - multi-file-upload-demo. I am not very keen in Javascript and stuff, so I copy a lot of logic from that implementation.

I made up my app following all logic from rounders demo, I have included all gems and javascript libraries, and I get an error:

Uncaught TypeError: Cannot read property 'innerHTML' of null

in chrome console, which refers to tmpl.js file

tmpl.load = function (id) {
    return document.getElementById(id).innerHTML;
};

My knowledge of JS doesn't make it clear to me which piece of code triggers that function so I can go further.

Can you advise me what are the next steps to investigate source of this problem? I expect potential reasons may be various, so I don't want to paste all code from the application.

Maciek Simm
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5 Answers5

38

This is old but I found an actual solution to this. Change your require in application.js to //=require jquery-fileupload/basic instead of //= require jquery-fileupload.

BlakeWilliams
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  • Thank you very much @BlakeWilliams! This should be marked as correct response, btw... – Andrea Salicetti Feb 02 '16 at 15:48
  • It seems than now works, Now I have to check all functionality over fileupload is working... and I would like to know the difference between require jquery-fileupload/basic and jquery-fileupload ... to avoid surprises – Albert Català Jun 09 '17 at 12:47
20

The reason you're getting this error is because you are missing a script tag id="template-upload" or id="template-download" or both.

Example from the Demo at: http://blueimp.github.com/jQuery-File-Upload/

<script id="template-upload" type="text/x-tmpl">
{% for (var i=0, file; file=o.files[i]; i++) { %}
    <tr class="template-upload fade">
        <td class="preview"><span class="fade"></span></td>
        <td class="name"><span>{%=file.name%}</span></td>
        <td class="size"><span>{%=o.formatFileSize(file.size)%}</span></td>
        {% if (file.error) { %}
            <td class="error" colspan="2"><span class="label label-important">Error</span> {%=file.error%}</td>
        {% } else if (o.files.valid && !i) { %}
            <td>
                <div class="progress progress-success progress-striped active" role="progressbar" aria-valuemin="0" aria-valuemax="100" aria-valuenow="0"><div class="bar" style="width:0%;"></div></div>
            </td>
            <td class="start">{% if (!o.options.autoUpload) { %}
                <button class="btn btn-primary">
                    <i class="icon-upload icon-white"></i>
                    <span>Start</span>
                </button>
            {% } %}</td>
        {% } else { %}
            <td colspan="2"></td>
        {% } %}
        <td class="cancel">{% if (!i) { %}
            <button class="btn btn-warning">
                <i class="icon-ban-circle icon-white"></i>
                <span>Cancel</span>
            </button>
        {% } %}</td>
    </tr>
{% } %}
</script>
<!-- The template to display files available for download -->
<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 { %}
            <td class="preview">{% if (file.thumbnail_url) { %}
                <a href="{%=file.url%}" title="{%=file.name%}" data-gallery="gallery" download="{%=file.name%}"><img src="{%=file.thumbnail_url%}"></a>
            {% } %}</td>
            <td class="name">
                <a href="{%=file.url%}" 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 class="delete">
            <button class="btn btn-danger" 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>Delete</span>
            </button>
            <input type="checkbox" name="delete" value="1">
        </td>
    </tr>
{% } %}
</script>

The UI version depends on both these templates being present.

I was having the same problem and decided to checkout what was missing.

Hope that helps.

Bill Billingson
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10

I ran into this same problem as well. However, loading the basic version of the file-upload plugin was not an option for me since I use previewing for one upload, but not for the other. You can disable the "preview" functionality and the attempted processing of template-upload and template-download on a case-by-case basis by setting the uploadTemplateId and downloadTemplateId options for the file-upload plugin to null.

Vivin Paliath
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2

The error message tells us that document.getElementById(id) is returning null, so there is no element currently in the document with the specified id.

To debug, try adding a call to console.log(id); before the return statement. Once you do that you can find the value of id that is causing the problem. Hopefully the error is the result of a simple typo, remember the value of id is case-sensitive. If a typo is not the problem, you can at least set a conditional breakpoint since you now know the value of id that you want to break on. After hitting the breakpoint, it's just a matter of stepping through to the calling functions to "see which piece of code triggers that function." Hope this helps.

gowansg
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1

I'm using this plugin for a few month, today i noticed that file upload didn't work, and i get an error 

"cannot read property 'innerHTML' of null error".

I looked into it, and its because a simple reason. the file path 

http://blueimp.github.io/JavaScript-Load-Image/js/load-image.min.js

changed to

http://blueimp.github.io/JavaScript-Load-Image/js/load-image.all.min.js

in the git of blueimp. as you could see here 

https://github.com/blueimp/jQuery-File-Upload

the path changed in this file.

https://github.com/blueimp/jQuery-File-Upload/blob/master/index.html

I changed to the right path and its works. hope this answer will help someone here that got same problem.

BenB
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