Trial an initial loader from DOM

.eslintrc.json

@@ -6,5 +6,8 @@
 	"parserOptions": {
 		"ecmaVersion": 2018,
 		"sourceType": "module"
+	},
+	"env": {
+		"browser": true
 	}
 }

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@ultraq/redux-utils",
-	"version": "0.2.0",
+	"version": "0.3.0",
 	"description": "A collection of wrappers/utilities for common functions in redux",
 	"author": "Emanuel Rabina <emanuelrabina@gmail.com> (http://www.ultraq.net.nz/)",
 	"license": "Apache-2.0",

redux-utils.js

@@ -16,6 +16,33 @@
 
 import {equals} from '@ultraq/object-utils';
 
+/**
+ * Create an initial state from JSON data in a DOM element.  Used for creating
+ * an object that is suitable for the `initialState` value of Redux's
+ * `createStore`.
+ * 
+ * @param {String} selector
+ *   A CSS selector for picking out the HTML element that contains the JSON data
+ *   to load.
+ * @param {String} [slice]
+ *   If the JSON data only represents a slice of the entire state, then specify
+ *   the name of the slice so that it can be set in the right place.
+ * @return {Object}
+ *   The JSON data converted to an object, or an empty object if no data could
+ *   be read.
+ */
+export function initialStateFromDom(selector, slice) {
+	let el = document.querySelector(selector);
+	if (el && el.textContent) {
+		let jsonData = el.textContent.trim();
+		if (jsonData) {
+			let data = JSON.parse(jsonData);
+			return slice ? {[slice]: data} : data;
+		}
+	}
+	return {};
+}
+
 /**
  * Observe the store for changes, passing the value picked out by the `select`
  * function to the handler.