@blueprintjs/core
Version:
Core styles & components
74 lines • 2.36 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.
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.isRefObject = isRefObject;
exports.isRefCallback = isRefCallback;
exports.setRef = setRef;
exports.mergeRefs = mergeRefs;
exports.getRef = getRef;
exports.refHandler = refHandler;
function isRefObject(value) {
return value != null && typeof value !== "function";
}
function isRefCallback(value) {
return typeof value === "function";
}
/**
* Assign the given ref to a target, either a React ref object or a callback which takes the ref as its first argument.
*/
function setRef(refTarget, ref) {
if (isRefObject(refTarget)) {
// HACKHACK: .current property is readonly
refTarget.current = ref;
}
else if (isRefCallback(refTarget)) {
refTarget(ref);
}
}
/**
* Utility for merging refs into one singular callback ref.
* If using in a functional component, would recomend using `useMemo` to preserve function identity.
*/
function mergeRefs(...refs) {
return value => {
refs.forEach(ref => {
setRef(ref, value);
});
};
}
function getRef(ref) {
if (ref === null) {
return null;
}
if (typeof ref.current === "undefined") {
return ref;
}
return ref.current;
}
/**
* Creates a ref handler which assigns the ref returned by React for a mounted component to a field on the target object.
* The target object is usually a component class.
*
* If provided, it will also update the given `refProp` with the value of the ref.
*/
function refHandler(refTargetParent, refTargetKey, refProp) {
return (ref) => {
refTargetParent[refTargetKey] = ref;
setRef(refProp, ref);
};
}
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