Function traverseAllChildrenImpl

docs/external/js/react.development.js:1063–1154

* @param {?*} children Children tree container. * @param {!string} nameSoFar Name of the key path so far. * @param {!function} callback Callback to invoke with each child found. * @param {?*} traverseContext Used to pass information throughout the traversal * process. * @return {!numb

(children, nameSoFar, callback, traverseContext)

  function traverseAllChildrenImpl(children, nameSoFar, callback, traverseContext) {
    var type = typeof children;

    if (type === 'undefined' || type === 'boolean') {
      // All of the above are perceived as null.
      children = null;
    }

    var invokeCallback = false;

    if (children === null) {
      invokeCallback = true;
    } else {
      switch (type) {
        case 'string':
        case 'number':
          invokeCallback = true;
          break;

        case 'object':
          switch (children.$$typeof) {
            case REACT_ELEMENT_TYPE:
            case REACT_PORTAL_TYPE:
              invokeCallback = true;
          }

      }
    }

    if (invokeCallback) {
      callback(traverseContext, children, // If it's the only child, treat the name as if it was wrapped in an array
      // so that it's consistent if the number of children grows.
      nameSoFar === '' ? SEPARATOR + getComponentKey(children, 0) : nameSoFar);
      return 1;
    }

    var child;
    var nextName;
    var subtreeCount = 0; // Count of children found in the current subtree.

    var nextNamePrefix = nameSoFar === '' ? SEPARATOR : nameSoFar + SUBSEPARATOR;

    if (Array.isArray(children)) {
      for (var i = 0; i < children.length; i++) {
        child = children[i];
        nextName = nextNamePrefix + getComponentKey(child, i);
        subtreeCount += traverseAllChildrenImpl(child, nextName, callback, traverseContext);
      }
    } else {
      var iteratorFn = getIteratorFn(children);

      if (typeof iteratorFn === 'function') {

        {
          // Warn about using Maps as children
          if (iteratorFn === children.entries) {
            if (!didWarnAboutMaps) {
              warn('Using Maps as children is deprecated and will be removed in ' + 'a future major release. Consider converting children to ' + 'an array of keyed ReactElements instead.');