Add endpoint to retrieve real-time input data

lib/www/server/api/index.js

@@ -132,6 +132,9 @@ app.map({
 // // 		post: [ mw.permissions.post ],
 // // 		delete: [ mw.permissions.delete ]
 // 	},
+	'/navdata/': {
+		get: [ mw.navdata.get ],
+	}
 //
 // 	'/user': {
 // 		get: [ mw.user.get ],

lib/www/server/api/middleware/index.js

@@ -7,5 +7,6 @@ module.exports = {
 	auth: require('./auth'),
 	gis: require('./gis'),
 	label: require('./label'),
+	navdata: require('./navdata'),
 	configuration: require('./configuration')
 };

lib/www/server/api/middleware/navdata/get.js

@@ -0,0 +1,13 @@
+
+const { navdata } = require('../../../lib/db');
+
+module.exports = async function (req, res, next) {
+
+	try {
+		res.status(200).send(await navdata.get(req.query));
+		next();
+	} catch (err) {
+		next(err);
+	}
+
+};

lib/www/server/api/middleware/navdata/index.js

@@ -0,0 +1,7 @@
+
+module.exports = {
+	get: require('./get'),
+	post: require('./post'),
+	put: require('./put'),
+	delete: require('./delete')
+}

lib/www/server/lib/db/navdata/get.js

@@ -0,0 +1,33 @@
+ 
+const { transaction, pool } = require('../connection');
+
+function fields (obj, keys) {
+	const retval = {};
+	for (const key of keys) {
+		retval[key] = obj[key];
+	}
+	return retval;
+}
+
+async function get (opts = {}) {
+	const client = await pool.connect();
+
+	const text = `
+		SELECT meta
+		FROM real_time_inputs
+		ORDER BY tstamp DESC
+		LIMIT $1
+		OFFSET $2
+	`;
+
+	const values = [ opts.limit || 300, opts.offset || 0 ];
+
+	const res = await client.query(text, values);
+	client.release();
+	return opts.fields
+		? res.rows.map(r => fields(r.meta, opts.fields.split(/[;,\s]+/)))
+		: res.rows.map(r => r.meta);
+}
+
+
+module.exports = get;

lib/www/server/lib/db/navdata/index.js

@@ -1,5 +1,6 @@
 
 module.exports = {
-	save: require('./save')
+	save: require('./save'),
+	get: require('./get')
 };