Function createElement$1

code/styling/public/app.js:16200–16250

(type, props, rootContainerElement, parentNamespace)

}

function createElement$1(type, props, rootContainerElement, parentNamespace) {
  var isCustomComponentTag = void 0;

  // We create tags in the namespace of their parent container, except HTML
  // tags get no namespace.
  var ownerDocument = getOwnerDocumentFromRootContainer(rootContainerElement);
  var domElement = void 0;
  var namespaceURI = parentNamespace;
  if (namespaceURI === HTML_NAMESPACE) {
    namespaceURI = getIntrinsicNamespace(type);
  }
  if (namespaceURI === HTML_NAMESPACE) {
    {
      isCustomComponentTag = isCustomComponent(type, props);
      // Should this check be gated by parent namespace? Not sure we want to
      // allow <SVG> or <mATH>.
      warning(isCustomComponentTag || type === type.toLowerCase(), '<%s /> is using uppercase HTML. Always use lowercase HTML tags ' + 'in React.', type);
    }

    if (type === 'script') {
      // Create the script via .innerHTML so its "parser-inserted" flag is
      // set to true and it does not execute
      var div = ownerDocument.createElement('div');
      div.innerHTML = '<script><' + '/script>'; // eslint-disable-line
      // This is guaranteed to yield a script element.
      var firstChild = div.firstChild;
      domElement = div.removeChild(firstChild);
    } else if (typeof props.is === 'string') {
      // $FlowIssue `createElement` should be updated for Web Components
      domElement = ownerDocument.createElement(type, { is: props.is });
    } else {
      // Separate else branch instead of using `props.is || undefined` above because of a Firefox bug.
      // See discussion in https://github.com/facebook/react/pull/6896
      // and discussion in https://bugzilla.mozilla.org/show_bug.cgi?id=1276240
      domElement = ownerDocument.createElement(type);
    }
  } else {
    domElement = ownerDocument.createElementNS(namespaceURI, type);
  }

  {
    if (namespaceURI === HTML_NAMESPACE) {
      if (!isCustomComponentTag && Object.prototype.toString.call(domElement) === '[object HTMLUnknownElement]' && !Object.prototype.hasOwnProperty.call(warnedUnknownTags, type)) {
        warnedUnknownTags[type] = true;
        warning(false, 'The tag <%s> is unrecognized in this browser. ' + 'If you meant to render a React component, start its name with ' + 'an uppercase letter.', type);
      }
    }
  }

  return domElement;
}

function createTextNode$1(text, rootContainerElement) {
  return getOwnerDocumentFromRootContainer(rootContainerElement).createTextNode(text);