Added universal expressions (short form functions): $ex (#232)

* Added short form functions: $f

* documented $f and reused $fn

* renamed $f to to $ex

Author: dbuezas

readme.md

@@ -353,8 +353,8 @@ entities:
       width: 1
       dash: dot
       color: deepskyblue
-    x: $fn () => [Date.now(), Date.now()]
-    y: $fn () => [0,1]
+    x: $ex [Date.now(), Date.now()]
+    y: [0, 1]
 layout:
   yaxis9:
     visible: false
@@ -749,13 +749,29 @@ The returned value will be used as value for the property where it is found. E.g
 name: $fn ({ hass }) => hass.states["sensor.garden_temperature"].state
 ```
 
+or a universal expression `$ex` (the parameters and arrow are added automatically):
+
+```js
+name: $ex hass.states["sensor.garden_temperature"].state
+```
+
+which can also take a block:
+
+```js
+name: |
+  $ex {
+    return hass.states["sensor.garden_temperature"].state
+  }
+```
+
 ### Available parameters:
 
 Remember you can add a `console.log(the_object_you_want_to_inspect)` and see its content in the devTools console.
 
 #### Everywhere:
 
 - `getFromConfig: (path) => value;` Pass a path (e.g `entities.0.name`) and get back its value
+- `get: (path) => value;` same as `getFromConfig`
 - `hass: HomeAssistant object;` For example: `hass.states["sensor.garden_temperature"].state` to get its current state
 - `vars: Record<string, any>;` You can communicate between functions with this. E.g `vars.temperatures = ys`
 - `path: string;` The path of the current function
@@ -784,8 +800,7 @@ type: custom:plotly-graph
 entities:
   - entity: sensor.garden_temperature
     name: |
-      $fn ({ ys,meta }) =>
-        meta.friendly_name + " " + ys[ys.length - 1]
+      $ex meta.friendly_name + " " + ys[ys.length - 1]
 ```
 
 #### Sharing data across functions
@@ -796,10 +811,8 @@ entities:
   - entity: sensor.garden_temperature
 
     # the fn attribute has no meaning, it is just a placeholder to put a function there. It can be any name not used by plotly
-    fn: |
-      $fn ({ ys, vars }) =>
-        vars.title = ys[ys.length - 1]
-title: $fn ({ vars }) => vars.title
+    fn: $ex vars.title = ys[ys.length - 1];
+title: $ex vars.title
 ```
 
 #### Histograms
@@ -808,7 +821,7 @@ title: $fn ({ vars }) => vars.title
 type: custom:plotly-graph
 entities:
   - entity: sensor.openweathermap_temperature
-    x: $fn ({ys,vars}) => ys
+    x: $ex ys
     type: histogram
 title: Temperature Histogram last 10 days
 hours_to_show: 10d
@@ -895,8 +908,8 @@ When true, the `x` and `y` properties of the traces won't be automatically fille
 type: custom:plotly-graph
 entities:
   - entity: sensor.temperature_in_celsius
-    x: $fn ({xs}) => xs
-    y: $fn ({ys}) => ys
+    x: $ex xs
+    y: $ex ys
 raw_plotly_config: true # defaults to false
 ```
 

src/parse-config/parse-config.ts

@@ -68,6 +68,7 @@ class ConfigParser {
       hass,
       css_vars,
       getFromConfig: () => "",
+      get: () => "",
     };
     for (const [key, value] of Object.entries(this.yaml_with_defaults)) {
       try {
@@ -101,6 +102,7 @@ class ConfigParser {
     this.fnParam.path = path;
     this.fnParam.getFromConfig = (pathQuery: string) =>
       this.getEvaledPath(pathQuery, path /* caller */);
+    this.fnParam.get = this.fnParam.getFromConfig;
 
     if (
       !this.fnParam.xs && // hasn't fetched yet
@@ -114,8 +116,15 @@ class ConfigParser {
       await this.fetchDataForEntity(entityPath);
     }
 
-    if (typeof value === "string" && value.startsWith("$fn")) {
-      value = myEval(value.slice(3));
+    if (typeof value === "string") {
+      if (typeof value === "string" && value.startsWith("$ex")) {
+        value =
+          "$fn ({ getFromConfig, get, hass, vars, path, css_vars, xs, ys, statistics, states, meta }) => " +
+          value.slice(3);
+      }
+      if (value.startsWith("$fn")) {
+        value = myEval(value.slice(3));
+      }
     }
     const error = getDeprecationError(path, value);
     if (error) this.errors?.push(error);
@@ -366,7 +375,8 @@ function isObjectOrArray(value) {
 function is$fn(value) {
   return (
     typeof value === "function" ||
-    (typeof value === "string" && value.startsWith("$fn"))
+    (typeof value === "string" && value.startsWith("$fn")) ||
+    (typeof value === "string" && value.startsWith("$ex"))
   );
 }
 
@@ -387,11 +397,12 @@ function removeOutOfRange(data: EntityData, range: [number, number]) {
     data.statistics.splice(last);
   }
 }
-
+type GetFromConfig = (
+  string
+) => ReturnType<InstanceType<typeof ConfigParser>["getEvaledPath"]>;
 type FnParam = {
-  getFromConfig: (
-    string
-  ) => ReturnType<InstanceType<typeof ConfigParser>["getEvaledPath"]>;
+  getFromConfig: GetFromConfig;
+  get: GetFromConfig;
   hass: HomeAssistant;
   vars: Record<string, any>;
   path: string;