Locator docs (#103129) (#103551)

* feat: 🎸 add locator_examples plugin

* feat: 🎸 add example app in locator_examples

* feat: 🎸 add locator_explorer plugin

* chore: 🤖 remove url_generaotrs_* example plugins

* docs: ✏️ update share plugin readme

* docs: ✏️ add locators readme

* docs: ✏️ update docs link in example plugin

* docs: ✏️ update navigation docs

* fix: 🐛 make P extend SerializableState

* test: 💍 update test mocks

* fix: 🐛 use correct type in ingest pipeline locator

* test: 💍 add missing methods in mock

* test: 💍 update test mocks

* chore: 🤖 update plugin list

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>
# Conflicts:
#	examples/locator_examples/kibana.json

docs/developer/best-practices/navigation.asciidoc

@@ -47,24 +47,26 @@ console.log(discoverUrl); // http://localhost:5601/bpr/s/space/app/discover
 const discoverUrlWithSomeState = core.http.basePath.prepend(`/discover#/?_g=(filters:!(),refreshInterval:(pause:!t,value:0),time:(from:'2020-09-10T11:39:50.203Z',to:'2020-09-10T11:40:20.249Z'))&_a=(columns:!(_source),filters:!(),index:'90943e30-9a47-11e8-b64d-95841ca0b247',interval:auto,query:(language:kuery,query:''),sort:!())`);
 ----
 
-Instead, each app should expose {kib-repo}tree/{branch}/src/plugins/share/public/url_generators/README.md[a URL generator].
-Other apps should use those URL generators for creating URLs. 
+Instead, each app should expose {kib-repo}tree/{branch}/src/plugins/share/common/url_service/locators/README.md[a locator].
+Other apps should use those locators for navigation or URL creation. 
 
 [source,typescript jsx]
 ----
-// Properly generated URL to *Discover* app. Generator code is owned by *Discover* app and available on *Discover*'s plugin contract.
-const discoverUrl = discoverUrlGenerator.createUrl({filters, timeRange});
+// Properly generated URL to *Discover* app. Locator code is owned by *Discover* app and available on *Discover*'s plugin contract.
+const discoverUrl = await plugins.discover.locator.getUrl({filters, timeRange});
+// or directly execute navigation
+await plugins.discover.locator.navigate({filters, timeRange});
 ----
 
-To get a better idea, take a look at *Discover* URL generator {kib-repo}tree/{branch}/src/plugins/discover/public/url_generator.ts[implementation].
+To get a better idea, take a look at *Discover* locator {kib-repo}tree/{branch}/src/plugins/discover/public/locator.ts[implementation].
 It allows specifying various **Discover** app state pieces like: index pattern, filters, query, time range and more.
 
-There are two ways to access other's app URL generator in your code:
+There are two ways to access locators of other apps:
 
 1. From a plugin contract of a destination app *(preferred)*. 
-2. Using URL generator service instance on `share` plugin contract (in case an explicit plugin dependency is not possible).
+2. Using locator client in `share` plugin (case an explicit plugin dependency is not possible).
 
-In case you want other apps to link to your app, then you should create a URL generator and expose it on your plugin's contract.
+In case you want other apps to link to your app, then you should create a locator and expose it on your plugin's contract.
 
 
 [[navigating-between-kibana-apps]]

docs/developer/plugin-list.asciidoc

@@ -187,7 +187,8 @@ so they can properly protect the data within their clusters.
 
 
 |{kib-repo}blob/{branch}/src/plugins/share/README.md[share]
-|Replaces the legacy ui/share module for registering share context menus.
+|The share plugin contains various utilities for displaying sharing context menu,
+generating deep links to other apps, and creating short URLs.
 
 
 |{kib-repo}blob/{branch}/src/plugins/spaces_oss/README.md[spacesOss]

examples/locator_examples/README.md

@@ -0,0 +1,8 @@
+# Locator examples
+
+This example plugin shows how to:
+
+ - Register a URL locator.
+ - Return locator from plugin contract.
+
+To run this example, use the command `yarn start --run-examples`. Navigate to the locator app.

examples/locator_examples/kibana.json

@@ -1,10 +1,12 @@
 {
-  "id": "urlGeneratorsExamples",
+  "id": "locatorExamples",
   "version": "0.0.1",
   "kibanaVersion": "kibana",
   "server": false,
   "ui": true,
   "requiredPlugins": ["share"],
   "optionalPlugins": [],
-  "extraPublicDirs": ["public/url_generator"]
+  "extraPublicDirs": [
+    "public/locator"
+  ]
 }

examples/locator_examples/public/index.ts

@@ -6,6 +6,14 @@
  * Side Public License, v 1.
  */
 
-import { AccessLinksExplorerPlugin } from './plugin';
+import { LocatorExamplesPlugin } from './plugin';
 
-export const plugin = () => new AccessLinksExplorerPlugin();
+export {
+  HelloLocator,
+  HelloLocatorV1Params,
+  HelloLocatorV2Params,
+  HelloLocatorParams,
+  HELLO_LOCATOR,
+} from './locator';
+
+export const plugin = () => new LocatorExamplesPlugin();

examples/locator_examples/public/locator.ts

@@ -0,0 +1,54 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { SerializableState, MigrateFunction } from 'src/plugins/kibana_utils/common';
+import { LocatorDefinition, LocatorPublic } from '../../../src/plugins/share/public';
+
+export const HELLO_LOCATOR = 'HELLO_LOCATOR';
+
+export interface HelloLocatorV1Params extends SerializableState {
+  name: string;
+}
+
+export interface HelloLocatorV2Params extends SerializableState {
+  firstName: string;
+  lastName: string;
+}
+
+export type HelloLocatorParams = HelloLocatorV2Params;
+
+const migrateV1ToV2: MigrateFunction<HelloLocatorV1Params, HelloLocatorV2Params> = (
+  v1: HelloLocatorV1Params
+) => {
+  const v2: HelloLocatorV2Params = {
+    firstName: v1.name,
+    lastName: '',
+  };
+
+  return v2;
+};
+
+export type HelloLocator = LocatorPublic<HelloLocatorParams>;
+
+export class HelloLocatorDefinition implements LocatorDefinition<HelloLocatorParams> {
+  public readonly id = HELLO_LOCATOR;
+
+  public readonly getLocation = async ({ firstName, lastName }: HelloLocatorParams) => {
+    return {
+      app: 'locatorExamples',
+      path: `/hello?firstName=${encodeURIComponent(firstName)}&lastName=${encodeURIComponent(
+        lastName
+      )}`,
+      state: {},
+    };
+  };
+
+  public readonly migrations = {
+    '0.0.2': (migrateV1ToV2 as unknown) as MigrateFunction,
+  };
+}

examples/locator_examples/public/plugin.tsx

@@ -8,44 +8,27 @@
 
 import { SharePluginStart, SharePluginSetup } from '../../../src/plugins/share/public';
 import { Plugin, CoreSetup, AppMountParameters, AppNavLinkStatus } from '../../../src/core/public';
-import {
-  HelloLinkGeneratorState,
-  createHelloPageLinkGenerator,
-  LegacyHelloLinkGeneratorState,
-  HELLO_URL_GENERATOR_V1,
-  HELLO_URL_GENERATOR,
-  helloPageLinkGeneratorV1,
-} from './url_generator';
+import { HelloLocator, HelloLocatorDefinition } from './locator';
 
-declare module '../../../src/plugins/share/public' {
-  export interface UrlGeneratorStateMapping {
-    [HELLO_URL_GENERATOR_V1]: LegacyHelloLinkGeneratorState;
-    [HELLO_URL_GENERATOR]: HelloLinkGeneratorState;
-  }
+interface SetupDeps {
+  share: SharePluginSetup;
 }
 
 interface StartDeps {
   share: SharePluginStart;
 }
 
-interface SetupDeps {
-  share: SharePluginSetup;
+export interface LocatorExamplesSetup {
+  locator: HelloLocator;
 }
 
-const APP_ID = 'urlGeneratorsExamples';
-
-export class AccessLinksExamplesPlugin implements Plugin<void, void, SetupDeps, StartDeps> {
-  public setup(core: CoreSetup<StartDeps>, { share: { urlGenerators } }: SetupDeps) {
-    urlGenerators.registerUrlGenerator(
-      createHelloPageLinkGenerator(async () => ({
-        appBasePath: (await core.getStartServices())[0].application.getUrlForApp(APP_ID),
-      }))
-    );
-
-    urlGenerators.registerUrlGenerator(helloPageLinkGeneratorV1);
+export class LocatorExamplesPlugin
+  implements Plugin<LocatorExamplesSetup, void, SetupDeps, StartDeps> {
+  public setup(core: CoreSetup<StartDeps>, plugins: SetupDeps) {
+    const locator = plugins.share.url.locators.create(new HelloLocatorDefinition());
 
     core.application.register({
-      id: APP_ID,
+      id: 'locatorExamples',
       title: 'Access links examples',
       navLinkStatus: AppNavLinkStatus.hidden,
       async mount(params: AppMountParameters) {
@@ -58,6 +41,10 @@ export class AccessLinksExamplesPlugin implements Plugin<void, void, SetupDeps,
         );
       },
     });
+
+    return {
+      locator,
+    };
   }
 
   public start() {}

examples/locator_explorer/README.md

@@ -1,6 +1,7 @@
-## Access links explorer
+# Locator explorer
+
+This example plugin shows how to:
 
-This example app shows how to:
  - Generate links to other applications
  - Generate dynamic links, when the target application is not known
  - Handle backward compatibility of urls

examples/locator_explorer/kibana.json

@@ -1,9 +1,9 @@
 {
-  "id": "urlGeneratorsExplorer",
+  "id": "locatorExplorer",
   "version": "0.0.1",
   "kibanaVersion": "kibana",
   "server": false,
   "ui": true,
-  "requiredPlugins": ["share", "urlGeneratorsExamples", "developerExamples"],
+  "requiredPlugins": ["share", "locatorExamples", "developerExamples"],
   "optionalPlugins": []
 }

examples/locator_explorer/public/app.tsx

@@ -8,9 +8,7 @@
 
 import React, { useState, useEffect } from 'react';
 import ReactDOM from 'react-dom';
-
 import { EuiPage } from '@elastic/eui';
-
 import { EuiButton } from '@elastic/eui';
 import { EuiPageBody } from '@elastic/eui';
 import { EuiPageContent } from '@elastic/eui';
@@ -21,44 +19,54 @@ import { EuiFieldText } from '@elastic/eui';
 import { EuiPageHeader } from '@elastic/eui';
 import { EuiLink } from '@elastic/eui';
 import { AppMountParameters } from '../../../src/core/public';
-import { UrlGeneratorsService } from '../../../src/plugins/share/public';
+import { SharePluginSetup } from '../../../src/plugins/share/public';
 import {
-  HELLO_URL_GENERATOR,
-  HELLO_URL_GENERATOR_V1,
-} from '../../url_generators_examples/public/url_generator';
+  HelloLocatorV1Params,
+  HelloLocatorV2Params,
+  HELLO_LOCATOR,
+} from '../../locator_examples/public';
 
 interface Props {
-  getLinkGenerator: UrlGeneratorsService['getUrlGenerator'];
+  share: SharePluginSetup;
 }
 
 interface MigratedLink {
-  isDeprecated: boolean;
   linkText: string;
   link: string;
+  version: string;
 }
 
-const ActionsExplorer = ({ getLinkGenerator }: Props) => {
+const ActionsExplorer = ({ share }: Props) => {
   const [migratedLinks, setMigratedLinks] = useState([] as MigratedLink[]);
   const [buildingLinks, setBuildingLinks] = useState(false);
   const [firstName, setFirstName] = useState('');
   const [lastName, setLastName] = useState('');
+
   /**
    * Lets pretend we grabbed these links from a persistent store, like a saved object.
-   * Some of these links were created with older versions of the hello link generator.
-   * They use deprecated generator ids.
+   * Some of these links were created with older versions of the hello locator.
    */
-  const [persistedLinks, setPersistedLinks] = useState([
+  const [persistedLinks, setPersistedLinks] = useState<
+    Array<{
+      id: string;
+      version: string;
+      linkText: string;
+      params: HelloLocatorV1Params | HelloLocatorV2Params;
+    }>
+  >([
     {
-      id: HELLO_URL_GENERATOR_V1,
+      id: HELLO_LOCATOR,
+      version: '0.0.1',
       linkText: 'Say hello to Mary',
-      state: {
+      params: {
         name: 'Mary',
       },
     },
     {
-      id: HELLO_URL_GENERATOR,
+      id: HELLO_LOCATOR,
+      version: '0.0.2',
       linkText: 'Say hello to George',
-      state: {
+      params: {
         firstName: 'George',
         lastName: 'Washington',
       },
@@ -71,30 +79,38 @@ const ActionsExplorer = ({ getLinkGenerator }: Props) => {
     const updateLinks = async () => {
       const updatedLinks = await Promise.all(
         persistedLinks.map(async (savedLink) => {
-          const generator = getLinkGenerator(savedLink.id);
-          const link = await generator.createUrl(savedLink.state);
+          const locator = share.url.locators.get(savedLink.id);
+          if (!locator) return;
+          let params: HelloLocatorV1Params | HelloLocatorV2Params = savedLink.params;
+          if (savedLink.version === '0.0.1') {
+            const migration = locator.migrations['0.0.2'];
+            if (migration) {
+              params = migration(params) as HelloLocatorV2Params;
+            }
+          }
+          const link = await locator.getUrl(params, { absolute: false });
           return {
-            isDeprecated: generator.isDeprecated,
             linkText: savedLink.linkText,
             link,
-          };
+            version: savedLink.version,
+          } as MigratedLink;
         })
       );
-      setMigratedLinks(updatedLinks);
+      setMigratedLinks(updatedLinks as MigratedLink[]);
       setBuildingLinks(false);
     };
 
     updateLinks();
-  }, [getLinkGenerator, persistedLinks]);
+  }, [share, persistedLinks]);
 
   return (
     <EuiPage>
       <EuiPageBody>
-        <EuiPageHeader>Access links explorer</EuiPageHeader>
+        <EuiPageHeader>Locator explorer</EuiPageHeader>
         <EuiPageContent>
           <EuiPageContentBody>
             <EuiText>
-              <p>Create new links using the most recent version of a url generator.</p>
+              <p>Create new links using the most recent version of a locator.</p>
             </EuiText>
             <EuiFieldText
               prepend="First name"
@@ -108,8 +124,9 @@ const ActionsExplorer = ({ getLinkGenerator }: Props) => {
                 setPersistedLinks([
                   ...persistedLinks,
                   {
-                    id: HELLO_URL_GENERATOR,
-                    state: { firstName, lastName },
+                    id: HELLO_LOCATOR,
+                    version: '0.0.2',
+                    params: { firstName, lastName },
                     linkText: `Say hello to ${firstName} ${lastName}`,
                   },
                 ])
@@ -122,10 +139,10 @@ const ActionsExplorer = ({ getLinkGenerator }: Props) => {
             <EuiText>
               <p>
                 Existing links retrieved from storage. The links that were generated from legacy
-                generators are in red. This can be useful for developers to know they will have to
+                locators are in red. This can be useful for developers to know they will have to
                 migrate persisted state or in a future version of Kibana, these links may no longer
-                work. They still work now because legacy url generators must provide a state
-                migration function.
+                work. They still work now because legacy locators must provide state migration
+                functions.
               </p>
             </EuiText>
             {buildingLinks ? (
@@ -134,7 +151,7 @@ const ActionsExplorer = ({ getLinkGenerator }: Props) => {
               migratedLinks.map((link) => (
                 <React.Fragment>
                   <EuiLink
-                    color={link.isDeprecated ? 'danger' : 'primary'}
+                    color={link.version !== '0.0.2' ? 'danger' : 'primary'}
                     data-test-subj="linkToHelloPage"
                     href={link.link}
                     target="_blank"

examples/locator_explorer/public/index.ts

@@ -6,6 +6,6 @@
  * Side Public License, v 1.
  */
 
-import { AccessLinksExamplesPlugin } from './plugin';
+import { LocatorExplorerPlugin } from './plugin';
 
-export const plugin = () => new AccessLinksExamplesPlugin();
+export const plugin = () => new LocatorExplorerPlugin();

examples/locator_explorer/public/plugin.tsx

@@ -6,30 +6,30 @@
  * Side Public License, v 1.
  */
 
-import { SharePluginStart } from '../../../src/plugins/share/public';
+import { SharePluginSetup, SharePluginStart } from '../../../src/plugins/share/public';
 import { Plugin, CoreSetup, AppMountParameters, AppNavLinkStatus } from '../../../src/core/public';
 import { DeveloperExamplesSetup } from '../../developer_examples/public';
 
+interface SetupDeps {
+  developerExamples: DeveloperExamplesSetup;
+  share: SharePluginSetup;
+}
+
 interface StartDeps {
   share: SharePluginStart;
 }
 
-interface SetupDeps {
-  developerExamples: DeveloperExamplesSetup;
-}
-
-export class AccessLinksExplorerPlugin implements Plugin<void, void, SetupDeps, StartDeps> {
-  public setup(core: CoreSetup<StartDeps>, { developerExamples }: SetupDeps) {
+export class LocatorExplorerPlugin implements Plugin<void, void, SetupDeps, StartDeps> {
+  public setup(core: CoreSetup<StartDeps>, { developerExamples, share }: SetupDeps) {
     core.application.register({
-      id: 'urlGeneratorsExplorer',
-      title: 'Access links explorer',
+      id: 'locatorExplorer',
+      title: 'Locator explorer',
       navLinkStatus: AppNavLinkStatus.hidden,
       async mount(params: AppMountParameters) {
-        const depsStart = (await core.getStartServices())[1];
         const { renderApp } = await import('./app');
         return renderApp(
           {
-            getLinkGenerator: depsStart.share.urlGenerators.getUrlGenerator,
+            share,
           },
           params
         );
@@ -37,18 +37,18 @@ export class AccessLinksExplorerPlugin implements Plugin<void, void, SetupDeps,
     });
 
     developerExamples.register({
-      title: 'Url generators',
-      description: `Url generators offer are a backward compatible safe way to persist a URL in a saved object.
-       Store the url generator id and state, instead of the href string. When the link is recreated at run time, the service
+      title: 'URL locators',
+      description: `Locators offer are a backward compatible safe way to persist a URL in a saved object.
+       Store the locator ID and params, instead of the href string. When the link is recreated at run time, the service
        will run the state through any necessary migrations. Registrators can change their URL structure
        without breaking these links stored in saved objects.
       `,
-      appId: 'urlGeneratorsExplorer',
+      appId: 'locatorExplorer',
       links: [
         {
           label: 'README',
           href:
-            'https://github.com/elastic/kibana/blob/master/src/plugins/share/public/url_generators/README.md',
+            'https://github.com/elastic/kibana/blob/master/src/plugins/share/common/url_service/locators/README.md',
           iconType: 'logoGithub',
           size: 's',
           target: '_blank',

examples/url_generators_examples/README.md

@@ -1,7 +0,0 @@
-## Access links examples
-
-This example app shows how to:
- - Register a direct access link generator.
- - Handle migration of legacy generators into a new one.
-
-To run this example, use the command `yarn start --run-examples`. Navigate to the access links explorer app

examples/url_generators_examples/public/url_generator.ts

@@ -1,68 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License
- * 2.0 and the Server Side Public License, v 1; you may not use this file except
- * in compliance with, at your election, the Elastic License 2.0 or the Server
- * Side Public License, v 1.
- */
-
-import url from 'url';
-import { UrlGeneratorState, UrlGeneratorsDefinition } from '../../../src/plugins/share/public';
-
-/**
- * The name of the latest variable can always stay the same so code that
- * uses this link generator statically will switch to the latest version.
- * Typescript will warn the developer if incorrect state is being passed
- * down.
- */
-export const HELLO_URL_GENERATOR = 'HELLO_URL_GENERATOR_V2';
-
-export interface HelloLinkState {
-  firstName: string;
-  lastName: string;
-}
-
-export type HelloLinkGeneratorState = UrlGeneratorState<HelloLinkState>;
-
-export const createHelloPageLinkGenerator = (
-  getStartServices: () => Promise<{ appBasePath: string }>
-): UrlGeneratorsDefinition<typeof HELLO_URL_GENERATOR> => ({
-  id: HELLO_URL_GENERATOR,
-  createUrl: async (state) => {
-    const startServices = await getStartServices();
-    const appBasePath = startServices.appBasePath;
-    const parsedUrl = url.parse(window.location.href);
-
-    return url.format({
-      protocol: parsedUrl.protocol,
-      host: parsedUrl.host,
-      pathname: `${appBasePath}/hello`,
-      query: {
-        ...state,
-      },
-    });
-  },
-});
-
-/**
- * The name of this legacy generator id changes, but the *value* stays the same.
- */
-export const HELLO_URL_GENERATOR_V1 = 'HELLO_URL_GENERATOR';
-
-export interface HelloLinkStateV1 {
-  name: string;
-}
-
-export type LegacyHelloLinkGeneratorState = UrlGeneratorState<
-  HelloLinkStateV1,
-  typeof HELLO_URL_GENERATOR,
-  HelloLinkState
->;
-
-export const helloPageLinkGeneratorV1: UrlGeneratorsDefinition<typeof HELLO_URL_GENERATOR_V1> = {
-  id: HELLO_URL_GENERATOR_V1,
-  isDeprecated: true,
-  migrate: async (state) => {
-    return { id: HELLO_URL_GENERATOR, state: { firstName: state.name, lastName: '' } };
-  },
-};

src/plugins/discover/public/mocks.ts

@@ -21,6 +21,10 @@ const createSetupContract = (): Setup => {
       getUrl: jest.fn(),
       useUrl: jest.fn(),
       navigate: jest.fn(),
+      extract: jest.fn(),
+      inject: jest.fn(),
+      telemetry: jest.fn(),
+      migrations: {},
     },
   };
   return setupContract;
@@ -37,6 +41,10 @@ const createStartContract = (): Start => {
       getUrl: jest.fn(),
       useUrl: jest.fn(),
       navigate: jest.fn(),
+      extract: jest.fn(),
+      inject: jest.fn(),
+      telemetry: jest.fn(),
+      migrations: {},
     },
   };
   return startContract;

src/plugins/management/public/mocks/index.ts

@@ -39,6 +39,10 @@ const createSetupContract = (): ManagementSetup => ({
     getUrl: jest.fn(),
     useUrl: jest.fn(),
     navigate: jest.fn(),
+    extract: jest.fn(),
+    inject: jest.fn(),
+    telemetry: jest.fn(),
+    migrations: {},
   },
 });
 

src/plugins/share/README.md

@@ -1,24 +1,23 @@
 # Share plugin
 
-Replaces the legacy `ui/share` module for registering share context menus.
+The `share` plugin contains various utilities for displaying sharing context menu,
+generating deep links to other apps, and creating short URLs.
 
-## Example registration
+
+## Sharing context menu
+
+You can register an item into sharing context menu (which is displayed in
+Dahsboard, Discover, and Visuzlize apps).
+
+### Example registration
 
 ```ts
-// For legacy plugins
-import { npSetup } from 'ui/new_platform';
-npSetup.plugins.share.register(/* same details here */);
+import { ShareContext, ShareMenuItem } from 'src/plugins/share/public';
 
-// For new plugins: first add 'share' to the list of `optionalPlugins` 
-// in your kibana.json file. Then access the plugin directly in `setup`:
-
-class MyPlugin {
-  setup(core, plugins) {
-    if (plugins.share) {
-      plugins.share.register(/* same details here. */);
-    }
-  }
-}
+plugins.share.register({
+  id: 'MY_MENU',
+  getShareMenuItems: (context: ShareContext): ShareMenuItem[] => {
+    // ...
+  },
+};
 ```
-
-Note that the old module supported providing a Angular DI function to receive Angular dependencies. This is no longer supported as we migrate away from Angular and will be removed in 8.0.

src/plugins/share/common/url_service/locators/README.md

@@ -0,0 +1,166 @@
+# Locators
+
+## Locators service
+
+Developers who maintain pages in Kibana that other developers may want to link to
+can register a *locator*. Locators provide backward compatibility support
+so the developer of the app/page has a way to change their url structure without
+breaking users of this system. If users were to generate the URLs on their own, 
+using string concatenation, those links may break often.
+
+Owners: __Kibana App Services team__.
+
+
+## Producer Usage
+
+Here is how you create a *locator*, which deeply link into your Kibana app:
+
+```ts
+plugins.share.url.locators.create({
+  id: 'MY_APP_LOCATOR',
+  getLocation: async (params: { productId: string }) => {
+    return {
+      app: 'myApp',
+      path: `/products/${productId}`,
+      state: {},
+    };
+  },
+});
+```
+
+When navigation in Kibana is done without a page reload a serializable *location state*
+object is passed to the destination app, which the app can use to change its
+appearance. The *location state* object does not appear in the URL, but apps
+can still use that, similar to how URL parameters are used.
+
+```ts
+plugins.share.url.locators.create({
+  id: 'MY_APP_LOCATOR',
+  getLocation: async (params: { productId: string, tab?: 'pics' | 'attributes' }) => {
+    return {
+      app: 'myApp',
+      path: `/products/${productId}`,
+      state: {
+        tab: params.tab || 'pics',
+      },
+    };
+  },
+});
+```
+
+When you want to change the shape of the parameters that the locator receives, you can
+provide a migration function, which can transform the shape of the parameters from
+one Kibana version to another. For example, below we replace `productId` param by `id`.
+
+```ts
+plugins.share.url.locators.create({
+  id: 'MY_APP_LOCATOR',
+  getLocation: async (params: { id: string, tab?: 'pics' | 'attributes' }) => {
+    return {
+      app: 'myApp',
+      path: `/products/${id}`,
+      state: {
+        tab: params.tab || 'pics',
+      },
+    };
+  },
+
+  migrations = {
+    '7.20.0': ({productId, ...rest}) => {
+      return {
+        id: productId,
+        ...rest,
+      };
+    },
+  },
+});
+```
+
+The migration version should correspond to Kibana relase when the chagne was
+introduced. It is the responsibility of the *consumer* to make sure they
+migrate their stored parameters using the provided migration function to the
+latest version. Migrations versions are ordered by semver. As a consumer,
+if persist somewhere a locator parameters object, you also want to store
+the version of that object, so later you know from starting from which
+version you need to execute migrations.
+
+
+## Consumer Usage
+
+Consumers of the Locators service can use the locators to generate deeps links
+into Kibana apps, or navigate to the apps while passing to the destination
+app the *location state*.
+
+First you will need to get hold of the *locator* for the app you want to
+navigate to.
+
+Usually, that app will return it from its plugin contract from the "setup"
+life-cycle:
+
+```ts
+class MyPlugin {
+  setup(core, plugins) {
+    const locator = plugins.destinationApp.locator;
+  }
+}
+```
+
+Or, you can get hold of any locator from the central registry:
+
+```ts
+class MyPlugin {
+  setup(core, plugins) {
+    const locator = plugins.share.url.locators.get('DESTINATION_APP_LOCATOR');
+  }
+}
+```
+
+Once you have the locator, you can use it to navigate to some kibana app:
+
+```ts
+await locator.navigate({
+  productId: '123',
+});
+```
+
+You can also use it to generate a URL string of the destination:
+
+```ts
+const url = await locator.getUrl({
+  productId: '123',
+});
+```
+
+#### Migrations
+
+**As a consumer, you should not persist the resulting URL string!**
+
+As soon as you do, you have lost your migration options. Instead you should
+store the ID, version and params of your locator. This will let you
+re-create the migrated URL later.
+
+If, as a consumer, you store the ID, version and params of the locator, you
+should use the migration functions provided by the locator when migrating
+between Kibana versions.
+
+```ts
+const migration = locator.migrations[version];
+
+if (migration) {
+  params = migration(params);
+}
+```
+
+
+### Examples
+
+You can view the provided example plugins to learn more how to work with locators.
+There are two plugins (`locator_examples` and `locator_explorer`) provided in the
+`/examples` folder. You can run the example plugins using the following command:
+
+```
+yarn start --run-examples
+```
+
+To view the `locator_explorer` example plugin in Kibana navigate to: __Analytics__ 👉 
+__Developer examples__ 👉 __URL locators__.

src/plugins/share/common/url_service/locators/locator_client.ts

@@ -41,7 +41,7 @@ export class LocatorClient implements ILocatorClient {
    * @param id ID of a URL locator.
    * @returns A public interface of a registered URL locator.
    */
-  public get<P>(id: string): undefined | LocatorPublic<P> {
+  public get<P extends SerializableState>(id: string): undefined | LocatorPublic<P> {
     return this.locators.get(id);
   }
 }

src/plugins/share/common/url_service/locators/types.ts

@@ -25,7 +25,7 @@ export interface ILocatorClient {
    *
    * @param id Unique ID of the locator.
    */
-  get<P>(id: string): undefined | LocatorPublic<P>;
+  get<P extends SerializableState>(id: string): undefined | LocatorPublic<P>;
 }
 
 /**
@@ -50,7 +50,7 @@ export interface LocatorDefinition<P extends SerializableState>
 /**
  * Public interface of a registered locator.
  */
-export interface LocatorPublic<P> {
+export interface LocatorPublic<P extends SerializableState> extends PersistableState<P> {
   /**
    * Returns a reference to a Kibana client-side location.
    *

x-pack/plugins/discover_enhanced/public/actions/explore_data/explore_data_chart_action.test.ts

@@ -55,6 +55,10 @@ const setup = (
     navigate: jest.fn(async () => {}),
     getUrl: jest.fn(),
     useUrl: jest.fn(),
+    extract: jest.fn(),
+    inject: jest.fn(),
+    telemetry: jest.fn(),
+    migrations: {},
   };
 
   const plugins: PluginDeps = {

x-pack/plugins/discover_enhanced/public/actions/explore_data/explore_data_context_menu_action.test.ts

@@ -41,6 +41,10 @@ const setup = ({ dashboardOnlyMode = false }: { dashboardOnlyMode?: boolean } =
     navigate: jest.fn(async () => {}),
     getUrl: jest.fn(),
     useUrl: jest.fn(),
+    extract: jest.fn(),
+    inject: jest.fn(),
+    telemetry: jest.fn(),
+    migrations: {},
   };
 
   const plugins: PluginDeps = {

x-pack/plugins/ingest_pipelines/public/locator.test.ts

@@ -21,6 +21,10 @@ describe('Ingest pipeline locator', () => {
           throw new Error('not implemented');
         },
         useUrl: () => '',
+        telemetry: jest.fn(),
+        extract: jest.fn(),
+        inject: jest.fn(),
+        migrations: {},
       },
     });
     return { definition };

x-pack/plugins/ingest_pipelines/public/locator.ts

@@ -52,7 +52,7 @@ export type IngestPipelinesParams =
   | IngestPipelinesCloneParams
   | IngestPipelinesCreateParams;
 
-export type IngestPipelinesLocator = LocatorPublic<void>;
+export type IngestPipelinesLocator = LocatorPublic<IngestPipelinesParams>;
 
 export const INGEST_PIPELINES_APP_LOCATOR = 'INGEST_PIPELINES_APP_LOCATOR';