[ivette/states] sync state & value hooks

ivette/src/frama-c/states.js

@@ -30,7 +30,7 @@ export const PROJECT = 'frama-c.project' ;
    @summary State Notification Events.
    @description
    Event `'frama-c.state.<id>'` for project `<id>`.
-   The prefix `'frama-c-state.'` is exported as `States.STATE` in public API.
+   The prefix `'frama-c.state.'` is exported as `States.STATE` in public API.
 */
 export const STATE = 'frama-c.state.' ;
 
@@ -39,6 +39,8 @@ export const STATE = 'frama-c.state.' ;
 // --------------------------------------------------------------------------
 
 var currentProject = undefined ;
+var globalStates = {} ;
+var globalSync = {} ;
 
 Server.onReady(() => {
   Server.sendGET('kernel.project.getCurrent')
@@ -51,6 +53,7 @@ Server.onReady(() => {
 Server.onShutdown(() => {
   currentProject = undefined ;
   globalStates = {} ;
+  globalSync = {} ;
   Dome.emit(PROJECT);
 });
 
@@ -77,36 +80,32 @@ export function useProject()
  */
 export function setProject(project)
 {
-  Server.sendSET( 'kernel.project.setCurrent' , project );
-  currentProject = project ;
-  Dome.emit(PROJECT);
-}
-
-/**
-   @summary Clear Project Cache.
-   @param {string} [project] - the project identifier, defaults to current
-   @description
-   Remove all projectified values for the specified project
-   Emits `PROJECT`.
- */
-export function clearCache(project)
-{
-  const theProject = project || currentProject ;
-  if (theProject)
-    _.unset( globalStates , [theProject] );
-  Dome.emit(PROJECT);
+  if (Server.isRunning()) {
+    Server.sendSET( 'kernel.project.setCurrent' , project );
+    currentProject = project ;
+    Dome.emit(PROJECT);
+  }
 }
 
 // --------------------------------------------------------------------------
 // --- Projectified State
 // --------------------------------------------------------------------------
 
-var globalStates = {} ;
+function getValue(id,project) {
+  if (!project) return undefined;
+  return _.get( globalStates, [project,id] );
+}
+
+function setValue(id,project,value) {
+  const theProject = project || currentProject ;
+  if (!theProject) return ;
+  _.set( globalStates, [project,id], value );
+  Dome.emit( STATE + id , value );
+}
 
 /**
    @summary Projectified State (Custom React Hook).
    @param {string} id - the state identifier (mandatory)
-   @param {string} [project] - the project identifier, defaults to current
    @return {array} `[state,setState]` for the specified project
    @description
    Returns a getter and a setter for the specified state
@@ -116,23 +115,112 @@ var globalStates = {} ;
    Each state is associated to a specific event `frama-c-state.<id>` which is
    is used to notify updates. The hook also updates on `PROJECT` notifications.
  */
-export function useState(id,project)
+export function useState(id)
 {
-  const theEvent = STATE + id ;
-  Dome.useUpdate( PROJECT, theEvent );
-  const theProject = project || currentProject ;
-  if (!theProject) return NONE;
-  const thePath = [theProject,id] ;
-  const theValue = _.get( globalStates, thePath );
-  const setValue = (v) => {
-    _.set( globalStates, thePath, v );
-    Dome.emit(theEvent,v);
-  };
-  return [ theValue, setValue ];
+  Dome.useUpdate( PROJECT, STATE + id );
+  const project = currentProject ;
+  const value = getValue(id,project);
+  return [ value , (v) => setValue(id,project,v) ];
+}
+
+// --------------------------------------------------------------------------
+// --- Synchronized States
+// --------------------------------------------------------------------------
+
+class Synchro {
+
+  constructor(id) {
+    this.id = id ;
+    this.UPDATE = STATE + id ;
+    this.signal = id + '.sig' ;
+    this.get_rq = id + '.get' ;
+    this.set_rq = id + '.set' ;
+    this.insync = false ;
+    this.value = undefined ;
+    this.update = this.update.bind(this);
+    this.effect = this.effect.bind(this);
+    this.setValue = this.setValue.bind(this);
+    Dome.on( PROJECT , this.update );
+  }
+
+  value() {
+    if (!this.insync && Server.isRunning())
+      this.update();
+    return this.value ;
+  }
+
+  setValue(v) {
+    this.insync = true ;
+    this.value = v ;
+    Server.sendSET( this.set_rq , v );
+    Dome.emit( this.UPDATE );
+  }
+
+  update() {
+    const project = currentProject ;
+    this.insync = true ;
+    Server.sendGET( this.get_rq ).then((v) => {
+      this.value = v ;
+      Dome.emit( this.UPDATE );
+    });
+  }
+
+}
+
+const synchros = {} ;
+function synchro(id) {
+  let s = synchros[id] ;
+  if (!s) s = synchros[id] = new Synchro(id);
+  return s ;
+}
+
+Server.onReady(() => _.forEach( synchros , (s) => {
+  if (!s.insync) s.update();
+}));
+
+/**
+   @summary Use Synchronized State (Custom React Hook).
+   @parameter {string} id - name of the server state
+   @return {Array} `[ value , setValue ]` of the synchronized state
+   @description
+   Synchronization with some (projectified) server state:
+   - sends a `<id>.get` request to obtain the current value of the state;
+   - sends a `<id>.set` request to update the value of the state;
+   - listens to `<id>.sig` signal to stay in sync with server updates.
+ */
+export function useSyncState(id)
+{
+  let s = synchro(id) ;
+  Dome.useUpdate( s.UPDATE );
+  Server.useSignal( s.signal , s.update );
+  return [ s.value() , s.setValue ];
+}
+
+/**
+   @summary Use Synchronized Value (Custom React Hook).
+   @parameter {string} id - name of the server state
+   @return {any} current `value` of the state
+   @description
+   Synchronization with some (projectified) server value:
+   - sends a `<id>.get` request to obtain the current value of the state;
+   - listens to `<id>.sig` signal to stay in sync with server updates.
+ */
+export function useSyncValue(id)
+{
+  let s = synchro(id) ;
+  Dome.useUpdate( s.update );
+  React.useEffect( s.effect );
+  return s.value();
 }
 
 // --------------------------------------------------------------------------
 
-export default { useProject, setProject, useState, PROJECT };
+export default {
+  useProject, setProject,
+  useState,
+  useSyncState,
+  useSyncValue,
+  PROJECT, STATE
+};
 
 // --------------------------------------------------------------------------