cmis_file_preview.xml

<?xml version="1.0" encoding="UTF-8" ?>
<templates id="template" xml:space="preserve">

    <t t-name="CmisFilePreview">
        <div class="cmis_file_preview">
            <button
                type="button"
                 t-att-class="'btn ' + widget.attrs.color"
                 aria-label="Preview"
                 data-toggle="tooltip"
                 title="Preview"
            >
                <t t-if="widget.attrs.icon">
                    <span
                        t-att-class="'fa ' + widget.attrs.icon"
                    />
                </t>
                <span>
                    <t t-esc="widget.attrs.string" />
                </span>
            </button>
        </div>
    </t>
</templates>