Wrote some example client code

server/handler.js

@@ -1,20 +1,71 @@
 const database = require('./database.js');
 
+/* DOCS: The handler module connects the database to simpleQL.
+ * this will be user-implemented, but for now uses a fake database provided in database.js
+ * The 'scalars' will be objects containing a name and the type for each scalar field requested by a query.
+ * This can be used in several ways...
+ *
+ * The handlers should only handle scalar fields - compound fields will be queried separately by simpleQL.
+*/
+
 //the handler routines
 const handler = {
-	Book: scalars => {
+	Book: (parent, scalars) => {
+		//takes an object which is the result of the parent query, if there is one { typeName: 'Author', scalars: [scalars], context: parentObject }
+		//takes an array of scalar types as objects: { typeName: 'String', name: 'title' }
+		//must return an array of objects containing the results
+
+		let books = database.books;
+
+		//if this is a sub-query, use the parent to narrow the search
+		if (parent && parent.typeName == 'Author') {
+			//filter based on parent object
+			books = books.filter(b => b.author.name == parent.context.name);
+		}
+
+		//return all books
+		const fields = scalars.map(s => s.name);
+		return books.map(b => {
+			const ret = {};
+
+			if (fields.includes('title')) {
+				ret.title = b.title;
+			}
+
+			if (fields.includes('published')) {
+				ret.published = b.published;
+			}
+
+			return ret;
+		});
+	},
+
+	Author: (parent, scalars) => {
+		let authors = database.authors;
+
+		//if this is a sub-query, use the parent to find the author
+		if (parent && parent.typeName == 'Book') {
+			return authors.find(a => a.books.filter(b => b.title == parent.context.title).length > 0);
+		}
+
+		//return all authors
+		const fields = scalars.map(s => s.name);
+		return authors.map(a => {
+			const ret = {};
+
+			if (fields.includes('name')) {
+				ret.name = a.name;
+			}
+
+			return ret;
+		});
+	},
+
+	create: (matches, sets) => {
 		//TODO
 	},
 
-	Author: scalars => {
-		//TODO
-	},
-
-	create: (sets, matches) => {
-		//TODO
-	},
-
-	update: (sets, matches) => {
+	update: (matches, sets) => {
 		//TODO
 	},