Add shared javascript VMs and demo config

cmd/config.go

@@ -21,6 +21,7 @@ type config struct {
 	Levels     map[string]string
 	Interval   time.Duration
 	Mqtt       mqttConfig
+	Javascript map[string]interface{}
 	Influx     server.InfluxConfig
 	HEMS       typedConfig
 	Messaging  messagingConfig

cmd/demo.go

@@ -8,24 +8,60 @@ import (
 const demoYaml = `
 log: info
 
+javascript:
+- vm: shared
+  script: |
+    state = {
+      residualpower: 200,
+      pvpower: -3000,
+      batterypower: 200,
+      gridpower: -2000,
+      chargepower: 0,
+      maxcurrent: 0,
+      battery: 63, // car
+    };
+    function get() {
+      console.log("state:", JSON.stringify(state));
+    }
+    function set() {
+      console.log(param+":", val);
+      console.log("state:", JSON.stringify(state));
+    }
+
 meters:
 - name: grid
   type: default
   power:
     type: js
-    script: "1200"
+    vm: shared
+    script: state.gridpower = state.pvpower + state.chargepower + state.residualpower + state.batterypower;
+
 - name: pv
   type: default
   power:
     type: js
-    script: "6400"
+    vm: shared
+    script: state.pvpower += 100*Math.random();
+
 - name: battery
   type: default
   power:
     type: js
-    script: "200"
+    vm: shared
+    script: state.batterypower;
   soc:
     type: js
+    vm: shared
+    script: "30"
+- name: charge
+  type: default
+  power:
+    type: js
+    vm: shared
+    script: state.chargepower;
+  soc:
+    type: js
+    vm: shared
     script: "30"
 
 chargers:
@@ -33,16 +69,28 @@ chargers:
   type: default
   enable:
     type: js
-    script: "true"
+    vm: shared
+    script: |
+      set();
+      state.enabled = val;
+      if (state.enabled) state.chargepower = state.maxcurrent * 230; else state.chargepower = 0;
   enabled:
     type: js
-    script: "true"
+    vm: shared
+    script: |
+      state.enabled;
   status:
     type: js
-    script: "'B'"
+    vm: shared
+    script: |
+      if (state.enabled) "C"; else "B";
   maxcurrent:
     type: js
-    script: "6"
+    vm: shared
+    script: |
+      set();
+      state.maxcurrent = val;
+      if (state.enabled) state.chargepower = state.maxcurrent * 230;
 
 vehicles:
 - name: demo
@@ -50,7 +98,13 @@ vehicles:
   type: default
   charge:
     type: js
-    script: "63"
+    vm: shared
+    script: |
+      if (state.chargepower > 0) state.battery++; else state.battery--;
+      if (state.battery < 15) state.battery = 15;
+      if (state.battery > 100) state.battery = 100;
+      state.battery;
+  cache: 1s
 
 site:
   title: Demo
@@ -62,6 +116,8 @@ site:
 loadpoints:
 - title: Carport
   charger: demo
+  meters:
+    charge: charge
   vehicle: demo
 `
 

cmd/root.go

@@ -158,6 +158,9 @@ func run(cmd *cobra.Command, args []string) {
 		configureMQTT(conf.Mqtt)
 	}
 
+	// setup javascript VMs
+	configureJavascript(conf.Javascript)
+
 	// start broadcasting values
 	tee := &Tee{}
 

cmd/setup.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/andig/evcc/core"
 	"github.com/andig/evcc/hems"
+	"github.com/andig/evcc/provider/javascript"
 	"github.com/andig/evcc/provider/mqtt"
 	"github.com/andig/evcc/push"
 	"github.com/andig/evcc/server"
@@ -57,6 +58,13 @@ func configureMQTT(conf mqttConfig) {
 	}
 }
 
+// setup javascript
+func configureJavascript(conf map[string]interface{}) {
+	if err := javascript.Configure(conf); err != nil {
+		log.FATAL.Fatalf("failed configuring javascript: %v", err)
+	}
+}
+
 // setup HEMS
 func configureHEMS(conf typedConfig, site *core.Site, cache *util.Cache, httpd *server.HTTPd) hems.HEMS {
 	hems, err := hems.NewFromConfig(conf.Type, conf.Other, site, cache, httpd)

provider/javascript.go

@@ -1,6 +1,9 @@
 package provider
 
 import (
+	"strings"
+
+	"github.com/andig/evcc/provider/javascript"
 	"github.com/andig/evcc/util"
 	"github.com/robertkrimen/otto"
 )
@@ -19,6 +22,7 @@ func init() {
 // NewJavascriptProviderFromConfig creates a HTTP provider
 func NewJavascriptProviderFromConfig(other map[string]interface{}) (IntProvider, error) {
 	cc := struct {
+		VM     string
 		Script string
 	}{}
 
@@ -28,9 +32,11 @@ func NewJavascriptProviderFromConfig(other map[string]interface{}) (IntProvider,
 
 	log := util.NewLogger("js")
 
+	vm := javascript.RegisteredVM(strings.ToLower(cc.VM))
+
 	p := &Javascript{
 		log:    log,
-		vm:     otto.New(),
+		vm:     vm,
 		script: cc.Script,
 	}
 
@@ -85,10 +91,21 @@ func (p *Javascript) BoolGetter() func() (bool, error) {
 	}
 }
 
+func (p *Javascript) setParam(param string, val interface{}) error {
+	err := p.vm.Set(param, val)
+	if err == nil {
+		err = p.vm.Set("param", param)
+	}
+	if err == nil {
+		err = p.vm.Set("val", val)
+	}
+	return err
+}
+
 // IntSetter sends int request
 func (p *Javascript) IntSetter(param string) func(int64) error {
 	return func(val int64) error {
-		err := p.vm.Set(param, val)
+		err := p.setParam(param, val)
 		if err == nil {
 			_, err = p.vm.Eval(p.script)
 		}
@@ -99,7 +116,7 @@ func (p *Javascript) IntSetter(param string) func(int64) error {
 // StringSetter sends string request
 func (p *Javascript) StringSetter(param string) func(string) error {
 	return func(val string) error {
-		err := p.vm.Set(param, val)
+		err := p.setParam(param, val)
 		if err == nil {
 			_, err = p.vm.Eval(p.script)
 		}
@@ -110,7 +127,7 @@ func (p *Javascript) StringSetter(param string) func(string) error {
 // BoolSetter sends bool request
 func (p *Javascript) BoolSetter(param string) func(bool) error {
 	return func(val bool) error {
-		err := p.vm.Set(param, val)
+		err := p.setParam(param, val)
 		if err == nil {
 			_, err = p.vm.Eval(p.script)
 		}

provider/javascript/init.go

@@ -0,0 +1,56 @@
+package javascript
+
+import (
+	"github.com/andig/evcc/util"
+	"github.com/robertkrimen/otto"
+)
+
+// Configure initializes JS VMs
+func Configure(other map[string]interface{}) error {
+	cc := []struct {
+		VM     string
+		Script string
+	}{}
+
+	if err := util.DecodeOther(other, &cc); err != nil {
+		return err
+	}
+
+	// init all VMs that require it
+	for _, conf := range cc {
+		if conf.Script == "" {
+			continue
+		}
+
+		if _, ok := registry[conf.VM]; !ok {
+			vm := otto.New()
+
+			_, err := vm.Run(conf.Script)
+			if err != nil {
+				return err
+			}
+
+			registry[conf.VM] = vm
+		}
+	}
+
+	return nil
+}
+
+var registry = make(map[string]*otto.Otto)
+
+// RegisteredVM returns a JS VM. If name is not empty, it will return a shared instance.
+func RegisteredVM(name string) *otto.Otto {
+	vm, ok := registry[name]
+
+	// create new VM
+	if !ok {
+		vm = otto.New()
+
+		if name != "" {
+			registry[name] = vm
+		}
+	}
+
+	return vm
+}