@blueprintjs/core
Version:
Core styles & components
79 lines • 3.04 kB
JavaScript
/*
* Copyright 2020 Palantir Technologies, Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import * as React from "react";
/**
* Returns true if `node` is null/undefined, false, empty string, or an array
* composed of those. If `node` is an array, only one level of the array is
* checked, for performance reasons.
*/
export function isReactNodeEmpty(node, skipArray = false) {
return (node == null ||
node === "" ||
node === false ||
(!skipArray &&
Array.isArray(node) &&
// only recurse one level through arrays, for performance
(node.length === 0 || node.every(n => isReactNodeEmpty(n, true)))));
}
/**
* Converts a React node to an element: non-empty string or number or
* `React.Fragment` (React 16.3+) is wrapped in given tag name; empty strings
* and booleans are discarded.
*/
export function ensureElement(child, tagName = "span") {
if (child == null || typeof child === "boolean") {
return undefined;
}
else if (typeof child === "string") {
// cull whitespace strings
return child.trim().length > 0 ? React.createElement(tagName, {}, child) : undefined;
}
else if (typeof child === "number" || typeof child.type === "symbol" || Array.isArray(child)) {
// React.Fragment has a symbol type, ReactNodeArray extends from Array
return React.createElement(tagName, {}, child);
}
else if (isReactElement(child)) {
return child;
}
else {
// child is inferred as {}
return undefined;
}
}
export function isReactElement(child) {
return (typeof child === "object" &&
typeof child.type !== "undefined" &&
typeof child.props !== "undefined");
}
export function getDisplayName(ComponentClass) {
return ComponentClass.displayName || ComponentClass.name || "Unknown";
}
/**
* Returns true if the given JSX element matches the given component type.
*
* NOTE: This function only checks equality of `displayName` for performance and
* to tolerate multiple minor versions of a component being included in one
* application bundle.
* @param element JSX element in question
* @param ComponentType desired component type of element
*/
export function isElementOfType(element, ComponentType) {
return (element != null &&
element.type != null &&
element.type.displayName != null &&
element.type.displayName === ComponentType.displayName);
}
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