Reorganize JSON to immutable conversion

src/app.jsx

@@ -39,10 +39,10 @@ export default class App extends React.Component {
 	}
 
 	onStyleDownload() {
-		const mapStyle = JSON.stringify(this.state.currentStyle.toJS(), null, 4)
+		const mapStyle = JSON.stringify(this.state.currentStyle.toJSON(), null, 4)
 		const blob = new Blob([mapStyle], {type: "application/json;charset=utf-8"});
 		saveAs(blob, mapStyle.id + ".json");
-		this.onStyleSave(mapStyle)
+		this.onStyleSave()
 	}
 
 	onStyleUpload(newStyle) {
@@ -52,8 +52,7 @@ export default class App extends React.Component {
 
 	onStyleSave() {
 		const snapshotStyle = this.state.currentStyle.set('modified', new Date().toJSON())
-		const savedStyle = this.styleStore.save(snapshotStyle)
-		this.setState({ currentStyle: savedStyle })
+		this.setState({ currentStyle: snapshotStyle })
 	}
 
 	onStyleChanged(newStyle) {

src/map.jsx

@@ -1,8 +1,7 @@
 import React from 'react'
 import MapboxGl from 'mapbox-gl';
-import diffStyles from 'mapbox-gl-style-spec/lib/diff'
 import { fullHeight } from './theme.js'
-import { styleToJS } from './stylestore.js'
+import style from './style.js'
 import Immutable from 'immutable'
 
 export class Map extends React.Component {
@@ -16,27 +15,24 @@ export class Map extends React.Component {
 
 		// If the id has changed a new style has been uplaoded and
 		// it is safer to do a full new render
+		// TODO: might already be handled in diff algorithm?
 		const mapIdChanged = this.props.mapStyle.get('id') !== nextProps.mapStyle.get('id')
 
 		if(mapIdChanged || tokenChanged) {
-			this.state.map.setStyle(styleToJS(nextProps.mapStyle))
+			this.state.map.setStyle(style.toJSON(nextProps.mapStyle))
 			return
 		}
 
 		// TODO: If there is no map yet we need to apply the changes later?
-		// How to deal with that?
 		if(this.state.map) {
-			//TODO: Write own diff algo that operates on immutable collections
-			// Should be able to improve performance since we can only compare
-			// by reference
-			const changes = diffStyles(styleToJS(this.props.mapStyle), styleToJS(nextProps.mapStyle))
-			changes.forEach(change => {
+			style.diffStyles(this.props.mapStyle, nextProps.mapStyle).forEach(change => {
 				this.state.map[change.command].apply(this.state.map, change.args);
 			});
 		}
 	}
 
 	shouldComponentUpdate(nextProps, nextState) {
+		//TODO: If we enable this React mixin for immutable comparison we can remove this?
 		return nextProps.mapStyle !== this.props.mapStyle
 	}
 
@@ -45,7 +41,7 @@ export class Map extends React.Component {
 
 		const map = new MapboxGl.Map({
 			container: this.container,
-			style: styleToJS(this.props.mapStyle),
+			style: style.toJSON(this.props.mapStyle),
 		});
 
 		map.on("style.load", (...args) => {

src/style.js

@@ -1,6 +1,62 @@
 import React from 'react';
+import Immutable from 'immutable'
+import spec from 'mapbox-gl-style-spec/reference/latest.min.js'
+import diffJSONStyles from 'mapbox-gl-style-spec/lib/diff'
 import randomColor from 'randomcolor'
 
+// Standard JSON to Immutable conversion except layers
+// are stored in an OrderedMap to make lookups id fast
+// It also ensures that every style has an id and
+// a created date for future reference
+function fromJSON(jsonStyle) {
+	if (typeof jsonStyle === 'string' || jsonStyle instanceof String) {
+		jsonStyle = JSON.parse(jsonStyle)
+	}
+
+	if(!('id' in jsonStyle)) {
+		jsonStyle.id = Math.random().toString(36).substr(2, 9)
+	}
+
+	if(!('created' in jsonStyle)) {
+		jsonStyle.created = new Date().toJSON()
+	}
+
+	return new Immutable.Map(Object.keys(jsonStyle).map(key => {
+		const val = jsonStyle[key]
+		if(key === "layers") {
+			return [key, Immutable.OrderedMap(val.map(l => [l.id, Immutable.fromJS(l)]))]
+		} else if(key === "sources" || key === "metadata" || key === "transition") {
+			return [key, Immutable.Map(val)]
+		} else {
+			return [key, val]
+		}
+	}))
+}
+
+// Compare style with other style and return changes
+//TODO: Write own diff algo that operates on immutable collections
+// Should be able to improve performance since we can only compare
+// by reference
+function diffStyles(before, after) {
+	return diffJSONStyles(toJSON(before), toJSON(after))
+}
+
+// Turns immutable style back into JSON with the original order of the
+// layers preserved
+function toJSON(mapStyle) {
+	const jsonStyle = {}
+	for(let [key, value] of mapStyle.entries()) {
+		if(key === "layers") {
+			jsonStyle[key] = value.toIndexedSeq().toJS()
+		} else if(key === 'sources' || key === "metadata" || key === "transition") {
+			jsonStyle[key] = value.toJS()
+		} else {
+			jsonStyle[key] = value
+		}
+	}
+	return jsonStyle
+}
+
 export function colorizeLayers(layers) {
 	return layers.map(layer => {
 		if(!layer.metadata) {
@@ -12,3 +68,10 @@ export function colorizeLayers(layers) {
 	  return layer
 	})
 }
+
+export default {
+	colorizeLayers,
+	toJSON,
+	fromJSON,
+	diffStyles,
+}

src/stylestore.js

@@ -1,5 +1,6 @@
 import { colorizeLayers } from './style.js'
 import Immutable from 'immutable'
+import style from './style.js'
 
 const storagePrefix = "mapolo"
 const storageKeys = {
@@ -8,47 +9,32 @@ const storageKeys = {
 }
 
 // Empty style is always used if no style could be restored or fetched
-const emptyStyle = ensureOptionalStyleProps(makeStyleImmutable({
+const emptyStyle = style.fromJSON({
 		version: 8,
 		sources: {},
 		layers: [],
-}))
+})
 
 const defaultStyleUrl = "https://raw.githubusercontent.com/osm2vectortiles/mapbox-gl-styles/master/styles/basic-v9-cdn.json"
-
-// TODO: Stop converting around so much.. we should make a module containing the immutable style stuff
-export function styleToJS(mapStyle) {
-	const jsonStyle = mapStyle.toJS()
-	jsonStyle.layers = mapStyle.get('layers').toIndexedSeq().toJS()
-	return jsonStyle
-}
-
-function makeStyleImmutable(mapStyle) {
-  if(mapStyle instanceof Immutable.Map) return mapStyle
-	const style = Immutable.fromJS(mapStyle)
-	const orderdLayers = Immutable.OrderedMap(mapStyle.layers.map(l => [l.id, Immutable.fromJS(l)]))
-	return style.set('layers', orderdLayers)
-}
-
 // Fetch a default style via URL and return it or a fallback style via callback
 export function loadDefaultStyle(cb) {
-	var request = new XMLHttpRequest();
-	request.open('GET', defaultStyleUrl, true);
+	var request = new XMLHttpRequest()
+	request.open('GET', defaultStyleUrl, true)
 
 	request.onload = () => {
 		if (request.status >= 200 && request.status < 400) {
-			cb(makeStyleImmutable(JSON.parse(request.responseText)))
+			cb(style.fromJSON(request.responseText))
 		} else {
 			cb(emptyStyle)
 		}
-	};
+	}
 
 	request.onerror = function() {
 			console.log('Could not fetch default style')
 			cb(emptyStyle)
-	};
+	}
 
-	request.send();
+	request.send()
 }
 
 // Return style ids and dates of all styles stored in local storage
@@ -84,17 +70,6 @@ function styleKey(styleId) {
 	return [storagePrefix, styleId].join(":")
 }
 
-// Ensure a style has a unique id and a created date
-function ensureOptionalStyleProps(mapStyle) {
-		if(!mapStyle.has('id')) {
-			mapStyle = mapStyle.set('id', Math.random().toString(36).substr(2, 9))
-		}
-		if(!mapStyle.has('created')) {
-			mapStyle = mapStyle.set('created', new Date())
-		}
-		return mapStyle
-}
-
 // Store style independent settings
 export class SettingsStore {
 	get accessToken() {
@@ -120,18 +95,14 @@ export class StyleStore {
 		const styleId = window.localStorage.getItem(storageKeys.latest)
 		const styleItem = window.localStorage.getItem(styleKey(styleId))
 
-		if(styleItem) return makeStyleImmutable(JSON.parse(styleItem))
-		return memptyStyle
+		if(styleItem) return style.fromJSON(styleItem)
+		return emptyStyle
 	}
 
 	// Save current style replacing previous version
 	save(mapStyle) {
-		if(!(mapStyle instanceof Immutable.Map)) {
-			mapStyle = makeStyleImmutable(mapStyle)
-		}
-		mapStyle = ensureOptionalStyleProps(mapStyle)
 		const key = styleKey(mapStyle.get('id'))
-		window.localStorage.setItem(key, JSON.stringify(styleToJS(mapStyle)))
+		window.localStorage.setItem(key, JSON.stringify(style.toJSON(mapStyle)))
 		window.localStorage.setItem(storageKeys.latest, mapStyle.get('id'))
 		return mapStyle
 	}

src/toolbar.jsx

@@ -10,6 +10,7 @@ import MdSettings from 'react-icons/lib/md/settings'
 import MdLayers from 'react-icons/lib/md/layers'
 import MdSave from 'react-icons/lib/md/save'
 
+import { GlStyle } from './style.js'
 import { fullHeight } from './theme.js'
 import theme from './theme.js';
 
@@ -36,7 +37,7 @@ export class Toolbar extends React.Component {
 		reader.readAsText(file, "UTF-8");
 		reader.onload = e => {
 			const style = JSON.parse(e.target.result);
-			this.props.onStyleUpload(style);
+			this.props.onStyleUpload(GlStyle.fromJSON(style));
 		}
 		reader.onerror = e => console.log(e.target);
 	}