// Do not allow file attachments in rich text content
addEventListener("trix-file-accept", function(event) {
  event.preventDefault();
});

Trix.config.textAttributes.underline = {
    style: { "textDecoration": "underline" },
    inheritable: true,
    parser: function (element) {
        var style = window.getComputedStyle(element);
        return style.textDecoration === "underline";
    }
}

document.addEventListener('trix-initialize', function (e) {
    const trix = e.target;
    const toolBar = trix.toolbarElement;

    // // Creation of the button
    const button = document.createElement("button");
    button.setAttribute("type", "button");
    button.setAttribute("class", "trix-button trix-button--icon trix-button--icon-underline");
    button.setAttribute("data-trix-attribute", "underline");
    button.setAttribute("title", "underline");
    button.setAttribute("tabindex", "-1");
    button.innerText = "U";

    // Attachment of the button to the toolBar
    toolBar.querySelector('.trix-button-group--text-tools').appendChild(button);
});