created new toml config file

installed composer
created new file to load part of config file and return as json
added user editable units in config file

.gitignore

@@ -27,3 +27,5 @@ Modules/*/
 Theme/*
 Theme/*/
 !Theme/basic/
+
+/vendor/

composer.json

@@ -0,0 +1,9 @@
+{
+    "name": "emoncms/emoncms",
+    "description": "Web-app for processing, logging and visualising energy, temperature and other environmental data https://emoncms.org",
+    "type": "project",
+    "require": {
+        "yosymfony/toml": "^1.0"
+    },
+    "license": "GNU AFFERO GENERAL PUBLIC LICENSE"
+}

custom-config.toml

@@ -0,0 +1,63 @@
+# This is a config file for saving user editable editable settings.
+# Written in TOML to standardize the config file format
+# https://github.com/toml-lang/toml
+
+[version]
+title = "Emoncms Settings"
+date = 2018-09-20T20:43:11Z
+
+# common engeneering units - add [[units]] before the "short" and "long" names
+# this list will appear whenever you select units within the system
+
+[[units]]
+short = "W"
+long = "Watt"
+[[units]]
+short = "kWh"
+long = "Kilowatt Hour"
+
+[[units]]
+short = "Wh"
+long = "Watt-Hour"
+
+[[units]]
+short = "V"
+long = "Volt"
+
+[[units]]
+short = "VA"
+long = "Volt-Ampere"
+
+[[units]]
+short = "A"
+long = "Ampere"
+
+[[units]]
+short = "°C"
+long = "Celsius"
+
+[[units]]
+short = "K"
+long = "Kelvin"
+
+[[units]]
+short = "°F"
+long = "Fahrenheit"
+
+[[units]]
+short = "%"
+long = "Percent"
+
+[[units]]
+short = "Hz"
+long = "Hertz"
+
+[[units]]
+short = "pulses"
+long = "Pulses"
+
+[[units]]
+short = "dB"
+long = "Decibel"
+
+

units.php

@@ -0,0 +1,30 @@
+<?php
+/**
+ * load a config file and return units it as json
+ */
+
+require __DIR__ . '/vendor/autoload.php';
+use Yosymfony\Toml\Toml;
+// https://github.com/yosymfony/toml
+
+$filename = 'custom-config.toml';
+try {
+    $config = Toml::ParseFile($filename);
+} catch (Exception $e) {
+    $config = array("success"=>false,"message"=>$e->getMessage());
+}
+header('Content-Type: application/json');
+echo json_encode($config['units'],JSON_UNESCAPED_UNICODE);
+
+
+/**
+ * @ todo: create api endpoint to add to the config file??
+ * you can use the TomlBuilder class to build toml data from PHP
+ */
+// use Yosymfony\Toml\TomlBuilder;
+// $tb = new TomlBuilder();
+// $values = $tb->addComment('edited by [user] on [date]')
+//     ->addTable('widget')
+//     ->addValue('height', "120px")
+//     ->getTomlString();
+// file_put_contents ($filename , $values, FILE_APPEND);