mithril/api/mount-redraw.js

A framework for building brilliant applications

"use strict"

var Vnode = require("../render/vnode")

module.exports = function(render, schedule, console) {
	var subscriptions = []
	var rendering = false
	var pending = false

	function sync() {
		if (rendering) throw new Error("Nested m.redraw.sync() call")
		rendering = true
		for (var i = 0; i < subscriptions.length; i += 2) {
			try { render(subscriptions[i], Vnode(subscriptions[i + 1]), redraw) }
			catch (e) { console.error(e) }
		}
		rendering = false
	}

	function redraw() {
		if (!pending) {
			pending = true
			schedule(function() {
				pending = false
				sync()
			})
		}
	}

	redraw.sync = sync

	function mount(root, component) {
		if (component != null && component.view == null && typeof component !== "function") {
			throw new TypeError("m.mount(element, component) expects a component, not a vnode")
		}

		var index = subscriptions.indexOf(root)
		if (index >= 0) {
			subscriptions.splice(index, 2)
			render(root, [], redraw)
		}

		if (component != null) {
			subscriptions.push(root, component)
			render(root, Vnode(component), redraw)
		}
	}

	return {mount: mount, redraw: redraw}
}