extensibility: rules engine (#511)

* rules format prototype

* config container

* lightweight rules

* fdescribe

* basic rule integration

* migrate "create folder" to click actions

* migrate toolbar to new action handlers

* rule support for "create folder" (toolbar)

* upgrade "View" toolbar command

* migrate to rules

* cleanup tests

src/app.config.json

@@ -42,6 +42,28 @@
             "plugin2.json"
         ],
         "core": {
+            "rules": [
+                {
+                    "id": "app.create.canCreateFolder",
+                    "type": "app.navigation.folder.canCreate"
+                },
+                {
+                    "id": "app.toolbar.canEditFolder",
+                    "type": "core.every",
+                    "parameters": [
+                        { "type": "rule", "value": "app.selection.folder" },
+                        { "type": "rule", "value": "app.selection.folder.canUpdate" }
+                    ]
+                },
+                {
+                    "id": "app.toolbar.canViewFile",
+                    "type": "app.selection.file"
+                },
+                {
+                    "id": "app.toolbar.canDownload",
+                    "type": "app.selection.canDownload"
+                }
+            ],
             "routes": [
                 {
                     "id": "aca:routes/about",
@@ -81,11 +103,6 @@
                     "type": "SNACKBAR_INFO",
                     "payload": "I'm a nice little popup raised by extension."
                 },
-                {
-                    "id": "aca:actions/error",
-                    "type": "SNACKBAR_ERROR",
-                    "payload": "Aw, Snap!"
-                },
                 {
                     "id": "aca:actions/node-name",
                     "type": "SNACKBAR_INFO",
@@ -100,14 +117,14 @@
             "features": {
                 "create": [
                     {
-                        "disabled": false,
+                        "id": "app.create.folder",
-                        "id": "aca:create/folder",
-                        "order": 100,
                         "icon": "create_new_folder",
                         "title": "ext: Create Folder",
-                        "target": {
+                        "actions": {
-                            "permissions": ["create"],
+                            "click": "aca:actions/create-folder"
-                            "action": "aca:actions/create-folder"
+                        },
+                        "rules": {
+                            "enabled": "app.create.canCreateFolder"
                         }
                     }
                 ],
@@ -210,10 +227,11 @@
                             "order": 10,
                             "title": "APP.NEW_MENU.TOOLTIPS.CREATE_FOLDER",
                             "icon": "create_new_folder",
-                            "target": {
+                            "actions": {
-                                "types": [],
+                                "click": "aca:actions/create-folder"
-                                "permissions": ["parent.create"],
+                            },
-                                "action": "aca:actions/create-folder"
+                            "rules": {
+                                "visible": "app.create.canCreateFolder"
                             }
                         },
                         {
@@ -222,10 +240,11 @@
                             "order": 15,
                             "title": "APP.ACTIONS.VIEW",
                             "icon": "open_in_browser",
-                            "target": {
+                            "actions": {
-                                "types": ["file"],
+                                "click": "aca:actions/preview"
-                                "permissions": [],
+                            },
-                                "action": "aca:actions/preview"
+                            "rules": {
+                                "visible": "app.toolbar.canViewFile"
                             }
                         },
                         {
@@ -234,11 +253,11 @@
                             "order": 20,
                             "title": "APP.ACTIONS.DOWNLOAD",
                             "icon": "get_app",
-                            "target": {
+                            "actions": {
-                                "types": ["file", "folder"],
+                                "click": "aca:actions/download"
-                                "permissions": [],
+                            },
-                                "action": "aca:actions/download",
+                            "rules": {
-                                "multiple": true
+                                "visible": "app.toolbar.canDownload"
                             }
                         },
                         {
@@ -247,10 +266,11 @@
                             "order": 30,
                             "title": "APP.ACTIONS.EDIT",
                             "icon": "create",
-                            "target": {
+                            "actions": {
-                                "types": ["folder"],
+                                "click": "aca:actions/edit-folder"
-                                "permissions": ["update"],
+                            },
-                                "action": "aca:actions/edit-folder"
+                            "rules": {
+                                "visible": "app.toolbar.canEditFolder"
                             }
                         },
 
@@ -270,21 +290,8 @@
                                     "type": "button",
                                     "title": "Settings",
                                     "icon": "settings_applications",
-                                    "target": {
+                                    "actions": {
-                                        "types": [],
+                                        "click": "aca:actions/settings"
-                                        "permissions": [],
-                                        "action": "aca:actions/settings"
-                                    }
-                                },
-                                {
-                                    "id": "aca:action4",
-                                    "type": "button",
-                                    "title": "Error",
-                                    "icon": "report_problem",
-                                    "target": {
-                                        "types": ["file"],
-                                        "permissions": ["update", "delete"],
-                                        "action": "aca:actions/error"
                                     }
                                 }
                             ]

src/app/app.module.ts

@@ -85,6 +85,7 @@ import { SearchResultsRowComponent } from './components/search/search-results-ro
 import { NodePermissionsDialogComponent } from './dialogs/node-permissions/node-permissions.dialog';
 import { NodePermissionsDirective } from './common/directives/node-permissions.directive';
 import { PermissionsManagerComponent } from './components/permission-manager/permissions-manager.component';
+import { RuleService } from './extensions/rules/rule.service';
 
 @NgModule({
     imports: [
@@ -161,7 +162,8 @@ import { PermissionsManagerComponent } from './components/permission-manager/per
         ProfileResolver,
         ExperimentalGuard,
         ContentApiService,
-        ExtensionService
+        ExtensionService,
+        RuleService
     ],
     entryComponents: [
         LibraryDialogComponent,

src/app/components/page.component.ts

@@ -83,8 +83,7 @@ export abstract class PageComponent implements OnInit, OnDestroy {
                 if (selection.isEmpty) {
                     this.infoDrawerOpened = false;
                 }
-                const selectedNodes = selection ? selection.nodes : null;
+                this.actions = this.extensions.getAllowedContentActions();
-                this.actions = this.extensions.getAllowedContentActions(selectedNodes, this.node);
                 this.canUpdateFile = this.selection.file && this.content.canUpdateNode(selection.file);
                 this.canUpdateNode = this.selection.count === 1 && this.content.canUpdateNode(selection.first);
                 this.canDelete = !this.selection.isEmpty && this.content.canDeleteNodes(selection.nodes);

src/app/components/sidenav/sidenav.component.html

@@ -10,7 +10,7 @@
                     <button *ngFor="let entry of createActions"
                         mat-menu-item
                         [disabled]="entry.disabled"
-                        (click)="runAction(entry.target.action)">
+                        (click)="runAction(entry.actions.click)">
                         <mat-icon>{{ entry.icon }}</mat-icon>
                         <span>{{ entry.title | translate }}</span>
                     </button>

src/app/extensions/components/toolbar-action/toolbar-action.component.html

@@ -3,7 +3,7 @@
         mat-icon-button
         color="primary"
         title="{{ entry.title | translate }}"
-        (click)="runAction(entry.target.action)">
+        (click)="runAction(entry.actions.click)">
         <mat-icon>{{ entry.icon }}</mat-icon>
     </button>
     <adf-toolbar-divider *ngSwitchCase="'separator'"></adf-toolbar-divider>
@@ -20,7 +20,7 @@
             [overlapTrigger]="false">
             <ng-container *ngFor="let child of entry.children">
                 <button mat-menu-item
-                    (click)="runAction(child.target.action)">
+                    (click)="runAction(child.actions.click)">
                     <mat-icon>{{ child.icon }}</mat-icon>
                     <span>{{ child.title | translate }}</span>
                 </button>

src/app/extensions/content-action.extension.ts

@@ -38,10 +38,13 @@ export interface ContentActionExtension {
     icon?: string;
     disabled?: boolean;
     children?: Array<ContentActionExtension>;
-    target: {
+    actions?: {
-        types: Array<string>;
+        click?: string;
-        permissions: Array<string>,
+        [key: string]: string;
-        action: string;
+    };
-        multiple?: boolean;
+    rules: {
+        enabled?: string;
+        visible?: string;
+        [key: string]: string;
     };
 }

src/app/extensions/extension.config.ts

@@ -0,0 +1,35 @@
+/*!
+ * @license
+ * Alfresco Example Content Application
+ *
+ * Copyright (C) 2005 - 2018 Alfresco Software Limited
+ *
+ * This file is part of the Alfresco Example Content Application.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * The Alfresco Example Content Application is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * The Alfresco Example Content Application is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import { RouteExtension } from './route.extension';
+import { ActionExtension } from './action.extension';
+import { RuleRef } from './rules/rule-ref';
+
+export interface ExtensionConfig {
+    rules?: Array<RuleRef>;
+    routes?: Array<RouteExtension>;
+    actions?: Array<ActionExtension>;
+    features?: { [key: string]: any };
+}

src/app/extensions/extension.service.spec.ts

@@ -491,63 +491,6 @@ describe('ExtensionService', () => {
         });
     });
 
-    describe('permissions', () => {
-        it('should approve node permission', () => {
-            const node: any = {
-                allowableOperations: ['create']
-            };
-
-            expect(extensions.nodeHasPermission(node, 'create')).toBeTruthy();
-        });
-
-        it('should not approve node permission', () => {
-            const node: any = {
-                allowableOperations: ['create']
-            };
-
-            expect(extensions.nodeHasPermission(node, 'update')).toBeFalsy();
-        });
-
-        it('should not approve node permission when node missing property', () => {
-            const node: any = {
-                allowableOperations: null
-            };
-
-            expect(extensions.nodeHasPermission(node, 'update')).toBeFalsy();
-        });
-
-        it('should require node to check permission', () => {
-            expect(extensions.nodeHasPermission(null, 'create')).toBeFalsy();
-        });
-
-        it('should require permission value to check', () => {
-            const node: any = {
-                allowableOperations: ['create']
-            };
-            expect(extensions.nodeHasPermission(node, null)).toBeFalsy();
-        });
-
-        it('should approve multiple permissions', () => {
-            const node: any = {
-                allowableOperations: ['create', 'update', 'delete']
-            };
-            expect(
-                extensions.nodeHasPermissions(node, ['create', 'delete'])
-            ).toBeTruthy();
-        });
-
-        it('should require node to check multiple permissions', () => {
-            expect(extensions.nodeHasPermissions(null, ['create'])).toBeFalsy();
-        });
-
-        it('should require multiple permissions to check', () => {
-            const node: any = {
-                allowableOperations: ['create', 'update', 'delete']
-            };
-            expect(extensions.nodeHasPermissions(node, null)).toBeFalsy();
-        });
-    });
-
     describe('sorting', () => {
         it('should sort by provided order', () => {
             const sorted = [

src/app/extensions/extension.service.ts

@@ -36,7 +36,8 @@ import { AppStore } from '../store/states';
 import { Store } from '@ngrx/store';
 import { NavigationExtension } from './navigation.extension';
 import { Route } from '@angular/router';
-import { Node, MinimalNodeEntity } from 'alfresco-js-api';
+import { Node } from 'alfresco-js-api';
+import { RuleService } from './rules/rule.service';
 
 @Injectable()
 export class ExtensionService {
@@ -52,7 +53,8 @@ export class ExtensionService {
 
     constructor(
         private config: AppConfigService,
-        private store: Store<AppStore>
+        private store: Store<AppStore>,
+        private ruleService: RuleService
     ) {}
 
     // initialise extension service
@@ -89,6 +91,8 @@ export class ExtensionService {
                 []
             )
             .sort(this.sortByOrder);
+
+        this.ruleService.init();
     }
 
     getRouteById(id: string): RouteExtension {
@@ -183,38 +187,28 @@ export class ExtensionService {
 
     // evaluates create actions for the folder node
     getFolderCreateActions(folder: Node): Array<ContentActionExtension> {
-        return this.createActions.filter(this.filterEnabled).map(action => {
+        return this.createActions
-            if (
+            .filter(this.filterEnabled)
-                action.target &&
+            .filter(action => this.filterByRules(action))
-                action.target.permissions &&
+            .map(action => {
-                action.target.permissions.length > 0
+                let disabled = false;
-            ) {
+
+                if (action.rules && action.rules.enabled) {
+                    disabled = !this.ruleService.evaluateRule(action.rules.enabled);
+                }
+
                 return {
                     ...action,
-                    disabled: !this.nodeHasPermissions(
+                    disabled
-                        folder,
-                        action.target.permissions
-                    ),
-                    target: {
-                        ...action.target
-                    }
                 };
-            }
-            return action;
         });
     }
 
     // evaluates content actions for the selection and parent folder node
-    getAllowedContentActions(
+    getAllowedContentActions(): Array<ContentActionExtension> {
-        nodes: MinimalNodeEntity[],
-        parentNode: Node
-    ): Array<ContentActionExtension> {
         return this.contentActions
             .filter(this.filterEnabled)
-            .filter(action => this.filterByTarget(nodes, action))
+            .filter(action => this.filterByRules(action))
-            .filter(action =>
-                this.filterByPermission(nodes, action, parentNode)
-            )
             .reduce(this.reduceSeparators, [])
             .map(action => {
                 if (action.type === ContentActionType.menu) {
@@ -222,14 +216,7 @@ export class ExtensionService {
                     if (copy.children && copy.children.length > 0) {
                         copy.children = copy.children
                             .filter(childAction =>
-                                this.filterByTarget(nodes, childAction)
+                                this.filterByRules(childAction)
-                            )
-                            .filter(childAction =>
-                                this.filterByPermission(
-                                    nodes,
-                                    childAction,
-                                    parentNode
-                                )
                             )
                             .reduce(this.reduceSeparators, []);
                     }
@@ -301,108 +288,10 @@ export class ExtensionService {
         };
     }
 
-    filterByTarget(
+    filterByRules(action: ContentActionExtension): boolean {
-        nodes: MinimalNodeEntity[],
+        if (action && action.rules && action.rules.visible) {
-        action: ContentActionExtension
+            return this.ruleService.evaluateRule(action.rules.visible);
-    ): boolean {
-        if (!action) {
-            return false;
         }
-
+        return true;
-        if (!action.target) {
-            return (
-                action.type === ContentActionType.separator ||
-                action.type === ContentActionType.menu
-            );
-        }
-
-        const types = action.target.types || [];
-
-        if (types.length === 0) {
-            return true;
-        }
-
-        if (nodes && nodes.length > 0) {
-            return types.some(type => {
-                if (type === 'folder') {
-                    return action.target.multiple
-                        ? nodes.some(node => node.entry.isFolder)
-                        : nodes.length === 1 &&
-                              nodes.every(node => node.entry.isFolder);
-                }
-                if (type === 'file') {
-                    return action.target.multiple
-                        ? nodes.some(node => node.entry.isFile)
-                        : nodes.length === 1 &&
-                              nodes.every(node => node.entry.isFile);
-                }
-                return false;
-            });
-        }
-
-        return false;
-    }
-
-    filterByPermission(
-        nodes: MinimalNodeEntity[],
-        action: ContentActionExtension,
-        parentNode: Node
-    ): boolean {
-        if (!action) {
-            return false;
-        }
-
-        if (!action.target) {
-            return (
-                action.type === ContentActionType.separator ||
-                action.type === ContentActionType.menu
-            );
-        }
-
-        const permissions = action.target.permissions || [];
-
-        if (permissions.length === 0) {
-            return true;
-        }
-
-        return permissions.some(permission => {
-            if (permission.startsWith('parent.')) {
-                if (parentNode) {
-                    const parentQuery = permission.split('.')[1];
-                    return this.nodeHasPermission(parentNode, parentQuery);
-                }
-                return false;
-            }
-
-            if (nodes && nodes.length > 0) {
-                return action.target.multiple
-                    ? nodes.some(node =>
-                          this.nodeHasPermission(node.entry, permission)
-                      )
-                    : nodes.length === 1 &&
-                          nodes.every(node =>
-                              this.nodeHasPermission(node.entry, permission)
-                          );
-            }
-
-            return false;
-        });
-    }
-
-    nodeHasPermissions(node: Node, permissions: string[]): boolean {
-        if (node && permissions && permissions.length > 0) {
-            return permissions.some(permission =>
-                this.nodeHasPermission(node, permission)
-            );
-        }
-        return false;
-    }
-
-    nodeHasPermission(node: Node, permission: string): boolean {
-        if (node && permission) {
-            const allowableOperations = node.allowableOperations || [];
-            return allowableOperations.includes(permission);
-        }
-        return false;
     }
 }

src/app/extensions/rules/app.evaluators.ts

@@ -0,0 +1,72 @@
+/*!
+ * @license
+ * Alfresco Example Content Application
+ *
+ * Copyright (C) 2005 - 2018 Alfresco Software Limited
+ *
+ * This file is part of the Alfresco Example Content Application.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * The Alfresco Example Content Application is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * The Alfresco Example Content Application is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import { RuleContext } from './rule-context';
+import { RuleParameter } from './rule-parameter';
+import { Node } from 'alfresco-js-api';
+
+export function canCreateFolder(context: RuleContext, ...args: RuleParameter[]): boolean {
+    const folder = context.navigation.currentFolder;
+    if (folder) {
+        return nodeHasPermission(folder, 'create');
+    }
+    return false;
+}
+
+export function canDownloadSelection(context: RuleContext, ...args: RuleParameter[]): boolean {
+    if (!context.selection.isEmpty) {
+        return context.selection.nodes.every(node => {
+            return node.entry && (node.entry.isFile || node.entry.isFolder);
+        });
+    }
+    return false;
+
+}
+
+export function hasFolderSelected(context: RuleContext, ...args: RuleParameter[]): boolean {
+    const folder = context.selection.folder;
+    return folder ? true : false;
+}
+
+export function hasFileSelected(context: RuleContext, ...args: RuleParameter[]): boolean {
+    const file = context.selection.file;
+    return file ? true : false;
+}
+
+export function canUpdateSelectedFolder(context: RuleContext, ...args: RuleParameter[]): boolean {
+    const folder = context.selection.folder;
+    if (folder && folder.entry) {
+        return nodeHasPermission(folder.entry, 'update');
+    }
+    return false;
+}
+
+export function nodeHasPermission(node: Node, permission: string): boolean {
+    if (node && permission) {
+        const allowableOperations = node.allowableOperations || [];
+        return allowableOperations.includes(permission);
+    }
+    return false;
+}

src/app/extensions/rules/core.evaluators.ts

@@ -0,0 +1,47 @@
+/*!
+ * @license
+ * Alfresco Example Content Application
+ *
+ * Copyright (C) 2005 - 2018 Alfresco Software Limited
+ *
+ * This file is part of the Alfresco Example Content Application.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * The Alfresco Example Content Application is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * The Alfresco Example Content Application is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import { RuleContext } from './rule-context';
+import { RuleParameter } from './rule-parameter';
+
+export function every(context: RuleContext, ...args: RuleParameter[]): boolean {
+    if (!args || args.length === 0) {
+        return false;
+    }
+
+    return args
+        .map(arg => context.evaluators[arg.value])
+        .every(evaluator => evaluator(context));
+}
+
+export function some(context: RuleContext, ...args: RuleParameter[]): boolean {
+    if (!args || args.length === 0) {
+        return false;
+    }
+
+    return args
+        .map(arg => context.evaluators[arg.value])
+        .some(evaluator => evaluator(context));
+}

src/app/extensions/rules/rule-context.ts

@@ -0,0 +1,34 @@
+/*!
+ * @license
+ * Alfresco Example Content Application
+ *
+ * Copyright (C) 2005 - 2018 Alfresco Software Limited
+ *
+ * This file is part of the Alfresco Example Content Application.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * The Alfresco Example Content Application is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * The Alfresco Example Content Application is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import { SelectionState } from '../../store/states';
+import { RuleEvaluator } from './rule.service';
+import { NavigationState } from '../../store/states/navigation.state';
+
+export interface RuleContext {
+    selection: SelectionState;
+    navigation: NavigationState;
+    evaluators: { [key: string]: RuleEvaluator };
+}

src/app/extensions/rules/rule-parameter.ts

@@ -0,0 +1,29 @@
+/*!
+ * @license
+ * Alfresco Example Content Application
+ *
+ * Copyright (C) 2005 - 2018 Alfresco Software Limited
+ *
+ * This file is part of the Alfresco Example Content Application.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * The Alfresco Example Content Application is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * The Alfresco Example Content Application is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+export interface RuleParameter {
+    type: string;
+    value: any;
+}

src/app/extensions/rules/rule-ref.ts

@@ -0,0 +1,34 @@
+/*!
+ * @license
+ * Alfresco Example Content Application
+ *
+ * Copyright (C) 2005 - 2018 Alfresco Software Limited
+ *
+ * This file is part of the Alfresco Example Content Application.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * The Alfresco Example Content Application is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * The Alfresco Example Content Application is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import { RuleParameter } from './rule-parameter';
+import { RuleEvaluator } from './rule.service';
+
+export class RuleRef {
+    type: string;
+    id?: string;
+    parameters?: Array<RuleParameter>;
+    evaluator?: RuleEvaluator;
+}

src/app/extensions/rules/rule.service.ts

@@ -0,0 +1,97 @@
+/*!
+ * @license
+ * Alfresco Example Content Application
+ *
+ * Copyright (C) 2005 - 2018 Alfresco Software Limited
+ *
+ * This file is part of the Alfresco Example Content Application.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * The Alfresco Example Content Application is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * The Alfresco Example Content Application is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import { Injectable } from '@angular/core';
+import { AppConfigService } from '@alfresco/adf-core';
+import { every, some } from './core.evaluators';
+import { RuleContext } from './rule-context';
+import { RuleRef } from './rule-ref';
+import { createSelector, Store } from '@ngrx/store';
+import {
+    appSelection,
+    appNavigation
+} from '../../store/selectors/app.selectors';
+import { AppStore, SelectionState } from '../../store/states';
+import { NavigationState } from '../../store/states/navigation.state';
+import { canCreateFolder, hasFolderSelected, canUpdateSelectedFolder, hasFileSelected, canDownloadSelection } from './app.evaluators';
+
+export type RuleEvaluator = (context: RuleContext, ...args: any[]) => boolean;
+
+export const selectionWithFolder = createSelector(
+    appSelection,
+    appNavigation,
+    (selection, navigation) => {
+        return {
+            selection,
+            navigation
+        };
+    }
+);
+
+@Injectable()
+export class RuleService implements RuleContext {
+    rules: Array<RuleRef> = [];
+    evaluators: { [key: string]: RuleEvaluator } = {};
+    selection: SelectionState;
+    navigation: NavigationState;
+
+    constructor(
+        private config: AppConfigService,
+        private store: Store<AppStore>
+    ) {
+        this.evaluators['core.every'] = every;
+        this.evaluators['core.some'] = some;
+        this.evaluators['app.selection.canDownload'] = canDownloadSelection;
+        this.evaluators['app.selection.file'] = hasFileSelected;
+        this.evaluators['app.selection.folder'] = hasFolderSelected;
+        this.evaluators['app.selection.folder.canUpdate'] = canUpdateSelectedFolder;
+        this.evaluators['app.navigation.folder.canCreate'] = canCreateFolder;
+
+        this.store
+            .select(selectionWithFolder)
+            .subscribe(result => {
+                this.selection = result.selection;
+                this.navigation = result.navigation;
+            });
+    }
+
+    init() {
+        this.rules = this.config
+            .get<Array<RuleRef>>('extensions.core.rules', [])
+            .map(rule => {
+                rule.evaluator = this.evaluators[rule.type];
+                return rule;
+            });
+    }
+
+    evaluateRule(ruleId: string): boolean {
+        const ruleRef = this.rules.find(ref => ref.id === ruleId);
+
+        if (ruleRef.evaluator) {
+            return ruleRef.evaluator(this, ...ruleRef.parameters);
+        }
+        return false;
+    }
+}

src/app/store/selectors/app.selectors.ts

@@ -34,4 +34,5 @@ export const appSelection =  createSelector(selectApp, state => state.selection)
 export const appLanguagePicker = createSelector(selectApp, state => state.languagePicker);
 export const selectUser =  createSelector(selectApp, state => state.user);
 export const sharedUrl =  createSelector(selectApp, state => state.sharedUrl);
+export const appNavigation = createSelector(selectApp, state => state.navigation);
 export const currentFolder = createSelector(selectApp, state => state.navigation.currentFolder);

src/app/testing/app-testing.module.ts

@@ -60,6 +60,7 @@ import { NodeActionsService } from '../common/services/node-actions.service';
 import { NodePermissionService } from '../common/services/node-permission.service';
 import { ContentApiService } from '../services/content-api.service';
 import { ExtensionService } from '../extensions/extension.service';
+import { RuleService } from '../extensions/rules/rule.service';
 
 @NgModule({
     imports: [
@@ -112,7 +113,8 @@ import { ExtensionService } from '../extensions/extension.service';
         NodeActionsService,
         NodePermissionService,
         ContentApiService,
-        ExtensionService
+        ExtensionService,
+        RuleService
     ]
 })
 export class AppTestingModule {}