Add RED.hooks to editor

Gruntfile.js

@@ -137,6 +137,7 @@ module.exports = function(grunt) {
                     "packages/node_modules/@node-red/editor-client/src/js/jquery-addons.js",
                     "packages/node_modules/@node-red/editor-client/src/js/red.js",
                     "packages/node_modules/@node-red/editor-client/src/js/events.js",
+                    "packages/node_modules/@node-red/editor-client/src/js/hooks.js",
                     "packages/node_modules/@node-red/editor-client/src/js/i18n.js",
                     "packages/node_modules/@node-red/editor-client/src/js/settings.js",
                     "packages/node_modules/@node-red/editor-client/src/js/user.js",

packages/node_modules/@node-red/editor-client/src/js/hooks.js

@@ -0,0 +1,156 @@
+RED.hooks = (function() {
+
+    var VALID_HOOKS = [
+
+    ]
+
+    var hooks = { }
+    var labelledHooks = { }
+
+    function add(hookId, callback) {
+        var parts = hookId.split(".");
+        var id = parts[0], label = parts[1];
+
+        // if (VALID_HOOKS.indexOf(id) === -1) {
+        //     throw new Error("Invalid hook '"+id+"'");
+        // }
+        if (label && labelledHooks[label] && labelledHooks[label][id]) {
+            throw new Error("Hook "+hookId+" already registered")
+        }
+        var hookItem = {cb:callback, previousHook: null, nextHook: null }
+
+        var tailItem = hooks[id];
+        if (tailItem === undefined) {
+            hooks[id] = hookItem;
+        } else {
+            while(tailItem.nextHook !== null) {
+                tailItem = tailItem.nextHook
+            }
+            tailItem.nextHook = hookItem;
+            hookItem.previousHook = tailItem;
+        }
+
+        if (label) {
+            labelledHooks[label] = labelledHooks[label]||{};
+            labelledHooks[label][id] = hookItem;
+        }
+    }
+    function remove(hookId) {
+        var parts = hookId.split(".");
+        var id = parts[0], label = parts[1];
+        if ( !label) {
+            throw new Error("Cannot remove hook without label: "+hookId)
+        }
+        if (labelledHooks[label]) {
+            if (id === "*") {
+                // Remove all hooks for this label
+                var hookList = Object.keys(labelledHooks[label]);
+                for (var i=0;i<hookList.length;i++) {
+                    removeHook(hookList[i],labelledHooks[label][hookList[i]])
+                }
+                delete labelledHooks[label];
+            } else if (labelledHooks[label][id]) {
+                removeHook(id,labelledHooks[label][id])
+                delete labelledHooks[label][id];
+                if (Object.keys(labelledHooks[label]).length === 0){
+                    delete labelledHooks[label];
+                }
+            }
+        }
+    }
+
+    function removeHook(id,hookItem) {
+        var previousHook = hookItem.previousHook;
+        var nextHook = hookItem.nextHook;
+
+        if (previousHook) {
+            previousHook.nextHook = nextHook;
+        } else {
+            hooks[id] = nextHook;
+        }
+        if (nextHook) {
+            nextHook.previousHook = previousHook;
+        }
+        hookItem.removed = true;
+        if (!previousHook && !nextHook) {
+            delete hooks[id];
+        }
+    }
+
+    function trigger(hookId, payload, done) {
+        var hookItem = hooks[hookId];
+        if (!hookItem) {
+            if (done) {
+                done();
+            }
+            return;
+        }
+        function callNextHook(err) {
+            if (!hookItem || err) {
+                if (done) { done(err) };
+                return err;
+            }
+            if (hookItem.removed) {
+                hookItem = hookItem.nextHook;
+                return callNextHook();
+            }
+            var callback = hookItem.cb;
+            if (callback.length === 1) {
+                try {
+                    let result = callback(payload);
+                    if (result === false) {
+                        // Halting the flow
+                        if (done) { done(false) };
+                        return result;
+                    }
+                    hookItem = hookItem.nextHook;
+                    return callNextHook();
+                } catch(err) {
+                    console.warn(err);
+                    if (done) { done(err);}
+                    return err;
+                }
+            } else {
+                // There is a done callback
+                try {
+                    callback(payload,function(result) {
+                        if (result === undefined) {
+                            hookItem = hookItem.nextHook;
+                            callNextHook();
+                        } else {
+                            if (done) { done(result)};
+                        }
+                    })
+                } catch(err) {
+                    console.warn(err);
+                    if (done) { done(err) };
+                    return err;
+                }
+            }
+        }
+
+        return callNextHook();
+    }
+
+    function clear() {
+        hooks = {}
+        labelledHooks = {}
+    }
+
+    function has(hookId) {
+        var parts = hookId.split(".");
+        var id = parts[0], label = parts[1];
+        if (label) {
+            return !!(labelledHooks[label] && labelledHooks[label][id])
+        }
+        return !!hooks[id]
+    }
+
+    return {
+        has: has,
+        clear: clear,
+        add: add,
+        remove: remove,
+        trigger: trigger
+    }
+})();