refui/src/extras/parse.js

The JavaScript framework that refuels your UI projects, across web, native, and embedded

/* Copyright Yukino Song, SudoMaker Ltd.
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 { read, isSignal } from 'refui/signal'
import { Fn } from 'refui/components'
import { markStatic } from 'refui/utils'

const parseProps = {
	name: 'Parse'
}

const nullNamedProps = {
	name: null
}

export function Parse({ source, parser, expose }, ...children) {
	function onAppend(append) {
		expose?.({ append })
	}

	if (!isSignal(parser)) {
		return Fn(nullNamedProps, function() {
			return parser({ source, onAppend }, ...children)
		})
	}

	let currentParser = null
	let currentRender = null

	return Fn(parseProps, function () {
		const newParser = read(parser)

		if (currentParser === newParser) {
			return currentRender
		}

		currentParser = newParser

		return (currentRender = Fn(nullNamedProps, function() {
			return newParser({ source, onAppend }, ...children)
		}))
	})
}

markStatic(Parse)