spee.ch/views/partials/publishForm-Submit.handlebars

<div class="row">
    <div class="input-error" id="input-error-publish-submit" hidden="true"></div>
    <button id="publish-submit" class="button--primary button--large" onclick="publishSelectedImage(event)">Upload</button>
</div>
<div class="row row--short align-content-center">
    <button class="button--cancel" onclick="resetPublishArea()">Cancel</button>
</div>

<script type="text/javascript" >
    function resetPublishArea () {
        window.location.href = '/';
    }
    /* publish functions */
    // When a file is selected for publish, validate that file and
    // stage it so it will be ready when the publish button is clicked.
    function previewAndStageFile(selectedFile){
        const publishForm = document.getElementById('publish-form-wrapper');
        var previewHolder = document.getElementById('asset-preview-holder');
        var dropzone = document.getElementById('publish-drop-zone-wrapper');
        var previewReader = new FileReader();
        var nameInput = document.getElementById('claim-name-input');
        // validate the file's name, type, and size
        try {
            validateFile(selectedFile);
        } catch (error) {
            showError('input-error-file-selection', error.message);
            return;
        }
        // set the image preview, if an image was provided
        if (selectedFile.type !== 'video/mp4') {
            previewReader.readAsDataURL(selectedFile);
            previewReader.onloadend = function () {
                previewHolder.innerHTML = '<img width="100%" src="' + previewReader.result + '" alt="image preview"/>';
            };
        }
        // hide the drop zone
        dropzone.hidden = true;
        publishForm.hidden = false;
        // set the name input value to the image name if none is set yet
        if (nameInput.value === "") {
            var filename = selectedFile.name.substring(0, selectedFile.name.indexOf('.'))
            nameInput.value = cleanseClaimName(filename);
            checkClaimName(nameInput.value);
        }
        // store the selected file for upload
        stagedFiles = [selectedFile];
    }

    // Validate the publish submission and then trigger publishing.
    function publishSelectedImage(event) {
        var claimName = document.getElementById('claim-name-input').value;
        var channelName = document.getElementById('channel-name-select').value;
        // prevent default so this script can handle submission
        event.preventDefault();
        // validate, submit, and handle response
        validateFilePublishSubmission(stagedFiles, claimName, channelName)
                .then(() => {
                    uploader.submitFiles(stagedFiles);
                })
                .catch(error => {
                    if (error.name === 'FileError') {
                        showError(document.getElementById('input-error-file-selection'), error.message);
                    } else if (error.name === 'NameError') {
                        showError(document.getElementById('input-error-claim-name'), error.message);
                    } else if (error.name === 'ChannelNameError'){
                        console.log(error);
                        showError(document.getElementById('input-error-channel-select'), error.message);
                    } else {
                        showError(document.getElementById('input-error-publish-submit'), error.message);
                    }
                    return;
                })
    };
</script>