[MM-62066] Allow using plugin settings defined in manifest as fallback when using custom sections and plugin is disabled (#29500)

* Allow using plugin settings defined in manifest as fallback when using custom sections and plugin is disabled

* Update server/public/model/manifest.go

Co-authored-by: Christopher Poile <cpoile@gmail.com>

* Add custom setting case

---------

Co-authored-by: Christopher Poile <cpoile@gmail.com>
Co-authored-by: Mattermost Build <build@mattermost.com>

server/public/model/manifest.go

@@ -116,6 +116,9 @@ type PluginSettingsSection struct {
 
 	// If true, the section will load the custom component registered using `registry.registerAdminConsoleCustomSection`
 	Custom bool `json:"custom" yaml:"custom"`
+
+	// If true and Custom = true, the settings defined under this section will still render as fallback (unless the individual setting is type 'custom') when the plugin is disabled.
+	Fallback bool `json:"fallback" yaml:"fallback"`
 }
 
 type PluginSettingsSchema struct {

server/public/model/manifest_test.go

@@ -95,6 +95,18 @@ func TestIsValid(t *testing.T) {
 							},
 						},
 					},
+					{
+						Key:      "section3",
+						Custom:   true,
+						Fallback: true,
+						Settings: []*PluginSetting{
+							{
+								Key:         "section3setting1",
+								DisplayName: "thedisplayname",
+								Type:        "custom",
+							},
+						},
+					},
 				},
 			},
 		}, false},

webapp/channels/src/components/admin_console/custom_plugin_settings/index.test.tsx

@@ -167,6 +167,89 @@ describe('custom plugin sections and settings', () => {
         expect(screen.queryByText('Custom Section 2')).not.toBeInTheDocument();
     });
 
+    it('all custom sections with plugin disabled and fallback enabled should render available settings', () => {
+        const state = {
+            ...baseState,
+            entities: {
+                admin: {
+                    plugins: {
+                        testplugin: {
+                            ...plugin,
+                            settings_schema: {
+                                ...plugin.settings_schema,
+                                sections: [
+                                    {
+                                        key: 'section1',
+                                        title: 'Custom Section 1',
+                                        settings: [
+                                            {
+                                                key: 'customsection1numbersetting',
+                                                label: 'Custom Section Number Setting',
+                                                type: 'number' as const,
+                                                help_text: 'Custom Section Number Setting Help Text',
+                                            },
+                                        ],
+                                        custom: true,
+                                        fallback: true,
+                                    },
+                                    {
+                                        key: 'section2',
+                                        title: 'Custom Section 2',
+                                        settings: [
+                                            {
+                                                key: 'customsection2numbersetting',
+                                                label: 'Custom Section Bool Setting',
+                                                type: 'bool' as const,
+                                                help_text: 'Custom Section Bool Setting Help Text',
+                                            },
+                                            {
+                                                key: 'customsection2customsetting',
+                                                label: 'Custom Section Custom Setting',
+                                                type: 'custom' as const,
+                                                help_text: 'Custom Section Custom Setting Help Text',
+                                            },
+                                        ],
+                                        custom: true,
+                                        fallback: true,
+                                    },
+                                ],
+                            },
+                        },
+                    },
+                },
+            },
+        };
+
+        const props = {
+            ...baseProps,
+            config: {
+                ...baseProps.config,
+                PluginStates: {
+                    testplugin: {
+                        Enabled: false,
+                    },
+                },
+            },
+        };
+
+        renderWithContext(
+            <CustomPluginSettings
+                {...props}
+                patchConfig={jest.fn()}
+            />
+            , {...state});
+
+        expect(screen.getByText('testplugin')).toBeInTheDocument();
+        expect(screen.getByTestId('PluginSettings.PluginStates.testplugin.Enable')).toBeInTheDocument();
+        expect(screen.queryByText('In order to view and configure plugin settings, enable the plugin and click Save.')).not.toBeInTheDocument();
+        expect(screen.queryByText('Custom Section 1')).toBeInTheDocument();
+        expect(screen.queryByText('Custom Section 2')).toBeInTheDocument();
+        expect(screen.getByText('Custom Section Number Setting Help Text')).toBeInTheDocument();
+        expect(screen.getByText('Custom Section Bool Setting Help Text')).toBeInTheDocument();
+        expect(screen.queryByText('Custom Section Custom Setting Help Text')).not.toBeInTheDocument();
+        expect(screen.getByText('In order to view this setting, enable the plugin and click Save.')).toBeInTheDocument();
+    });
+
     it('custom sections with plugin enabled should render as expected', () => {
         const CustomSection1 = () => {
             return (

webapp/channels/src/components/admin_console/custom_plugin_settings/index.ts

@@ -95,8 +95,10 @@ function makeGetPluginSchema() {
                         if (customSections[key]) {
                             component = customSections[key]?.component;
                             settings = parsePluginSettings(section.settings);
+                        } else if (section.fallback) {
+                            settings = parsePluginSettings(section.settings);
                         } else {
-                            // Show warning banner for custom sections when the plugin is disabled.
+                            // Show warning banner for custom sections when the plugin is disabled and there's no fallback.
                             settings = [{
                                 key: key + 'disabledWarning',
                                 type: Constants.SettingsTypes.TYPE_BANNER,
@@ -134,8 +136,11 @@ function makeGetPluginSchema() {
             if (plugin.id !== appsPluginID || appsFeatureFlagIsEnabled) {
                 const pluginEnableSetting = getEnablePluginSetting(plugin) as AdminDefinitionSetting;
 
-                if (plugin.settings_schema && plugin.settings_schema.sections?.every((s) => s.custom && !customSections[s.key.toLowerCase()])) {
-                    // If the plugin is composed of purely custom sections (e.g. Calls) and it's disabled (custom components are not found), we show a single warning.
+                const hasAllCustomSectionsDisabled = plugin.settings_schema?.sections?.every((s) => s.custom && !customSections[s.key.toLowerCase()]);
+                const allCustomSectionsAllowFallback = plugin.settings_schema?.sections?.every((s) => s.custom && s.fallback);
+
+                if (plugin.settings_schema && hasAllCustomSectionsDisabled && !allCustomSectionsAllowFallback) {
+                    // If the plugin is composed of purely custom sections (e.g. Calls), it's disabled (custom components are not found), and they don't allow a fallback, we show a single warning.
                     const warningBanner = {
                         key: 'admin.plugin.customSections.pluginDisabledWarning',
                         type: Constants.SettingsTypes.TYPE_BANNER,

webapp/platform/types/src/plugins.ts

@@ -55,6 +55,7 @@ export type PluginSettingSection = {
     header?: string;
     footer?: string;
     custom?: boolean;
+    fallback?: boolean;
 };
 
 export type PluginSetting = {