jiti-meet/react/features/base/redux/functions.js

92 lines
3.6 KiB
JavaScript

/**
* Sets specific properties of a specific state to specific values and prevents
* unnecessary state changes.
*
* @param {Object} target - The state on which the specified properties are to
* be set.
* @param {Object} source - The map of properties to values which are to be set
* on the specified target.
* @returns {Object} The specified target if the values of the specified
* properties equal the specified values; otherwise, a new state constructed
* from the specified target by setting the specified properties to the
* specified values.
*/
export function setStateProperties(target, source) {
let t = target;
for (const property in source) { // eslint-disable-line guard-for-in
t = setStateProperty(t, property, source[property], t === target);
}
return t;
}
/**
* Sets a specific property of a specific state to a specific value. Prevents
* unnecessary state changes (when the specified <tt>value</tt> is equal to the
* value of the specified <tt>property</tt> of the specified <tt>state</tt>).
*
* @param {Object} state - The (Redux) state from which a new state is to be
* constructed by setting the specified <tt>property</tt> to the specified
* <tt>value</tt>.
* @param {string} property - The property of <tt>state</tt> which is to be
* assigned the specified <tt>value</tt> (in the new state).
* @param {*} value - The value to assign to the specified <tt>property</tt>.
* @returns {Object} The specified <tt>state</tt> if the value of the specified
* <tt>property</tt> equals the specified <tt>value/tt>; otherwise, a new state
* constructed from the specified <tt>state</tt> by setting the specified
* <tt>property</tt> to the specified <tt>value</tt>.
*/
export function setStateProperty(state, property, value) {
return _setStateProperty(state, property, value, /* copyOnWrite */ true);
}
/* eslint-disable max-params */
/**
* Sets a specific property of a specific state to a specific value. Prevents
* unnecessary state changes (when the specified <tt>value</tt> is equal to the
* value of the specified <tt>property</tt> of the specified <tt>state</tt>).
*
* @param {Object} state - The (Redux) state from which a state is to be
* constructed by setting the specified <tt>property</tt> to the specified
* <tt>value</tt>.
* @param {string} property - The property of <tt>state</tt> which is to be
* assigned the specified <tt>value</tt>.
* @param {*} value - The value to assign to the specified <tt>property</tt>.
* @param {boolean} copyOnWrite - If the specified <tt>state</tt> is to not be
* modified, <tt>true</tt>; otherwise, <tt>false</tt>.
* @returns {Object} The specified <tt>state</tt> if the value of the specified
* <tt>property</tt> equals the specified <tt>value/tt> or <tt>copyOnWrite</tt>
* is truthy; otherwise, a new state constructed from the specified
* <tt>state</tt> by setting the specified <tt>property</tt> to the specified
* <tt>value</tt>.
*/
function _setStateProperty(state, property, value, copyOnWrite) {
// Delete state properties that are to be set to undefined. (It is a matter
// of personal preference, mostly.)
if (typeof value === 'undefined'
&& Object.prototype.hasOwnProperty.call(state, property)) {
const newState = copyOnWrite ? { ...state } : state;
if (delete newState[property]) {
return newState;
}
}
if (state[property] !== value) {
if (copyOnWrite) {
return {
...state,
[property]: value
};
}
state[property] = value;
}
return state;
}
/* eslint-enable max-params */