github.com/cockroachdb/cockroach@v20.2.0-alpha.1+incompatible/pkg/ui/src/util/find.ts (about)

     1  // Copyright 2018 The Cockroach Authors.
     2  //
     3  // Use of this software is governed by the Business Source License
     4  // included in the file licenses/BSL.txt.
     5  //
     6  // As of the Change Date specified in that file, in accordance with
     7  // the Business Source License, use of this software will be governed
     8  // by the Apache License, Version 2.0, included in the file
     9  // licenses/APL.txt.
    10  
    11  import React from "react";
    12  
    13  /**
    14   * findChildrenOfType performs a DFS of the supplied React children collection,
    15   * returning all children which are ReactElements of the supplied type.
    16   */
    17  export function findChildrenOfType<P>(children: React.ReactChild, type: string | React.ComponentClass<P> | React.SFC<P>): React.ReactElement<P>[] {
    18    const matchingChildren: React.ReactElement<P>[] = [];
    19    const childrenToSearch = React.Children.toArray(children);
    20    while (childrenToSearch.length > 0) {
    21      const child: React.ReactChild = childrenToSearch.shift();
    22      if (!isReactElement(child)) {
    23        continue;
    24      } else {
    25        if (child.type === type) {
    26          matchingChildren.push(child);
    27        }
    28        const { props } = child;
    29        if (props.children) {
    30          // Children added to front of search array for DFS.
    31          childrenToSearch.unshift(...React.Children.toArray(props.children));
    32        }
    33      }
    34    }
    35  
    36    return matchingChildren;
    37  }
    38  
    39  /**
    40   * Predicate function to determine if a react child is a ReactElement.
    41   */
    42  function isReactElement(child: React.ReactChild): child is React.ReactElement<any> {
    43    return (<React.ReactElement<any>>child).type !== undefined;
    44  }