Document makeDecorators for addons authors

addons/backgrounds/src/index.js

@@ -15,6 +15,7 @@ export const withBackgrounds = makeDecorator({
   name: 'backgrounds',
   parameterName: 'backgrounds',
   skipIfNoParametersOrOptions: true,
+  allowDeprecatedUsage: true,
   wrapper: (getStory, context, { options, parameters }) => {
     const backgrounds = parameters || options;
 

addons/info/src/index.js

@@ -87,6 +87,7 @@ function addInfo(storyFn, context, infoOptions) {
 export const withInfo = makeDecorator({
   name: 'withInfo',
   parameterName: 'info',
+  allowDeprecatedUsage: true,
   wrapper: (getStory, context, { options, parameters }) => {
     const storyOptions = parameters || options;
     const infoOptions = typeof storyOptions === 'string' ? { text: storyOptions } : storyOptions;

addons/knobs/src/index.js

@@ -77,6 +77,7 @@ export const withKnobs = makeDecorator({
   name: 'withKnobs',
   parameterName: 'knobs',
   skipIfNoParametersOrOptions: false,
+  allowDeprecatedUsage: true,
   wrapper: (getStory, context, { options, parameters }) => {
     const storyOptions = parameters || options;
     const allOptions = { ...defaultOptions, ...storyOptions };

addons/notes/src/index.js

@@ -10,6 +10,7 @@ export const withNotes = makeDecorator({
   name: 'withNotes',
   parameterName: 'notes',
   skipIfNoParametersOrOptions: true,
+  allowDeprecatedUsage: true,
   wrapper: (getStory, context, { options, parameters }) => {
     const channel = addons.getChannel();
 

docs/src/pages/addons/api/index.md

@@ -28,9 +28,7 @@ See how we can use this:
 import addonAPI from '@storybook/addons';
 
 // Register the addon with a unique name.
-addonAPI.register('my-organisation/my-addon', storybookAPI => {
-
-});
+addonAPI.register('my-organisation/my-addon', storybookAPI => {});
 ```
 
 Now you'll get an instance to our StorybookAPI. See the [api docs](/addons/api#storybook-api) for Storybook API regarding using that.
@@ -43,18 +41,12 @@ See how you can use this method:
 ```js
 import addonAPI from '@storybook/addons';
 
-const MyPanel = () => (
-  <div>
-    This is a panel.
-  </div>
-);
+const MyPanel = () => <div>This is a panel.</div>;
 
 // give a unique name for the panel
 addonAPI.addPanel('my-organisation/my-addon/panel', {
   title: 'My Addon',
-  render: () => (
-    <MyPanel />
-  ),
+  render: () => <MyPanel />,
 });
 ```
 
@@ -71,11 +63,9 @@ addonAPI.register('my-organisation/my-addon', storybookAPI => {
   // Also need to set a unique name to the panel.
   addonAPI.addPanel('my-organisation/my-addon/panel', {
     title: 'Notes',
-    render: () => (
-      <Notes channel={addonAPI.getChannel()} api={storybookAPI}/>
-    ),
-  })
-})
+    render: () => <Notes channel={addonAPI.getChannel()} api={storybookAPI} />,
+  });
+});
 ```
 
 ## Storybook API
@@ -96,18 +86,15 @@ Let's say you've got a story like this:
 ```js
 import { storiesOf } from '@storybook/react';
 
-storiesOf('heading', module)
-  .add('with text', () => (
-    <h1>Hello world</h1>
-  ));
+storiesOf('heading', module).add('with text', () => <h1>Hello world</h1>);
 ```
 
 This is how you can select the above story:
 
 ```js
 addonAPI.register('my-organisation/my-addon', storybookAPI => {
   storybookAPI.selectStory('heading', 'with text');
-})
+});
 ```
 
 ### storybookAPI.selectInCurrentKind()
@@ -161,7 +148,7 @@ This method allows you to get application url state with some changed params. Fo
 addonAPI.register('my-organisation/my-addon', storybookAPI => {
   const href = storybookAPI.getUrlState({
     selectedKind: 'kind',
-    selectedStory: 'story'
+    selectedStory: 'story',
   }).url;
 });
 ```
@@ -175,3 +162,33 @@ addonAPI.register('my-organisation/my-addon', storybookAPI => {
   storybookAPI.onStory((kind, story) => console.log(kind, story));
 });
 ```
+
+## `makeDecorator` API
+
+The `makeDecorator` API can be used to create decorators in the style of the official addons easily. Use it like so:
+
+```js
+import { makeDecorator } from '@storybook/addons';
+
+export makeDecorator({
+  name: 'withSomething',
+  parameterName: 'something',
+  wrapper: (storyFn, context, { parameters }) => {
+    // Do something with `parameters`, which are set via { something: ... }
+
+    // Note you may alter the story output if you like, although generally that's
+    // not advised
+    return storyFn(context);
+  }
+})
+```
+
+The options to `makeDecorator` are:
+
+- `name`: The name of the export (e.g. `withNotes`)
+- `parameterName`: The name of the parameter your addon uses. This should be unique.
+- `skipIfNoParametersOrOptions`: Don't run your decorator if the user hasn't set options (via `.addDecorator(withFoo(options)))`) or parameters (`.add('story', () => <Story/>, { foo: 'param' })`, or `.addParameters({foo: 'param'})`).
+- `allowDeprecatedUsage`: support the deprecated "wrapper" usage (`.add('story', () => withFoo(options)(() => <Story/>))`).
+- `wrapper`: your decorator function. Takes the `storyFn`, `context`, and both the `options` and `parameters` (as defined in `skipIfNoParametersOrOptions` above).
+
+Note if the parameters to a story include `{ foo: {disable: true } }` (where `foo` is the `parameterName` of your addon), your decorator will note be called.

docs/src/pages/addons/writing-addons/index.md

@@ -21,11 +21,11 @@ As shown in the above image, there's a communication channel that the Manager Ap
 
 With an addon, you can add more functionality to Storybook. Here are a few things you could do:
 
--   Add a panel to Storybook (like Action Logger).
--   Interact with the story and the panel.
--   Set and get URL query params.
--   Select a story.
--   Register keyboard shortcuts (coming soon).
+- Add a panel to Storybook (like Action Logger).
+- Interact with the story and the panel.
+- Set and get URL query params.
+- Select a story.
+- Register keyboard shortcuts (coming soon).
 
 With this, you can write some pretty cool addons. Look at our [Addon gallery](/addons/addon-gallery) to have a look at some sample addons.
 
@@ -43,21 +43,26 @@ We write a story for our addon like this:
 import React from 'react';
 import { storiesOf } from '@storybook/react';
 import { action } from '@storybook/addon-actions';
-import { WithNotes } from '../notes-addon';
+import withNotes from '../notes-addon';
 
 import Button from './Button';
 
 storiesOf('Button', module)
-  .add('with text', () => (
-    <WithNotes notes={'This is a very simple Button and you can click on it.'}>
-      <Button onClick={action('clicked')}>Hello Button</Button>
-    </WithNotes>
-  ))
-  .add('with some emoji', () => (
-    <WithNotes notes={'Here we use some emoji as the Button text. Doesn&apos;t it look nice?'}>
-      <Button onClick={action('clicked')}><span role="img" aria-label="so cool">😀 😎 👍 💯</span></Button>
-    </WithNotes>
-  ));
+  .addDecorator(withNotes)
+  .add('with text', () => <Button onClick={action('clicked')}>Hello Button</Button>, {
+    notes: 'This is a very simple Button and you can click on it.',
+  })
+  .add(
+    'with some emoji',
+    () => (
+      <Button onClick={action('clicked')}>
+        <span role="img" aria-label="so cool">
+          😀 😎 👍 💯
+        </span>
+      </Button>
+    ),
+    { notes: 'Here we use some emoji as the Button text. Doesn&apos;t it look nice?' }
+  );
 ```
 
 Then it will appear in the Notes panel like this:
@@ -79,23 +84,29 @@ Now we need to create two files, `register.js` and `index.js,` inside a director
 
 ## The Addon
 
-Let's add the following content to the `index.js`. It will expose a class called `WithNotes`, which wraps our story.
+Let's add the following content to the `index.js`. It will expose a decorator called `withNotes` which we use the `.addDecorator()` API to decorate all our stories.
+
+The `@storybook/addons` package contains a `makeDecorator` function which we can easily use to create such a decorator:
 
 ```js
 import React from 'react';
-import addons from '@storybook/addons';
-
-export class WithNotes extends React.Component {
-  render() {
-    const { children, notes } = this.props;
+import addons, { makeDecorator } from '@storybook/addons';
+
+export withNotes = makeDecorator({
+  name: 'withNotes',
+  parameterName: 'notes',
+  // This means don't run this decorator if the notes decorator is not set
+  skipIfNoParametersOrOptions: true,
+  wrapper: (getStory, context, {parameters}) => {
     const channel = addons.getChannel();
 
-    // send the notes to the channel.
-    channel.emit('MYADDON/add_notes', notes);
-    // return children elements.
-    return children;
+    // Our simple API above simply sets the notes parameter to a string,
+    // which we send to the channel
+    channel.emit('MYADDON/add_notes', parameters);
+
+    return story(context);
   }
-}
+})
 ```
 
 In this case, our component can access something called the channel. It lets us communicate with the panel (where we display notes). It has a NodeJS [EventEmitter](https://nodejs.org/api/events.html) compatible API.
@@ -122,7 +133,7 @@ class Notes extends React.Component {
 
   onAddNotes = text => {
     this.setState({ text });
-  }
+  };
 
   componentDidMount() {
     const { channel, api } = this.props;
@@ -138,11 +149,9 @@ class Notes extends React.Component {
   render() {
     const { text } = this.state;
     const { active } = this.props;
-    const textAfterFormatted = text? text.trim().replace(/\n/g, '<br />') : "";
+    const textAfterFormatted = text ? text.trim().replace(/\n/g, '<br />') : '';
 
-    return active ? 
-      <NotesPanel dangerouslySetInnerHTML={{ __html: textAfterFormatted }} /> :
-      null;
+    return active ? <NotesPanel dangerouslySetInnerHTML={{ __html: textAfterFormatted }} /> : null;
   }
 
   // This is some cleanup tasks when the Notes panel is unmounting.
@@ -158,15 +167,13 @@ class Notes extends React.Component {
 }
 
 // Register the addon with a unique name.
-addons.register('MYADDON', (api) => {
+addons.register('MYADDON', api => {
   // Also need to set a unique name to the panel.
   addons.addPanel('MYADDON/panel', {
     title: 'Notes',
-    render: ({ active }) => (
-      <Notes channel={addons.getChannel()} api={api} active={active} />
-    ),
-  })
-})
+    render: ({ active }) => <Notes channel={addons.getChannel()} api={api} active={active} />,
+  });
+});
 ```
 
 It will register our addon and add a panel. In this case, the panel represents a React component called `Notes`. That component has access to the channel and storybook api.
@@ -199,21 +206,26 @@ That's it. Now you can create notes for any story as shown below:
 import React from 'react';
 import { storiesOf } from '@storybook/react';
 import { action } from '@storybook/addon-actions';
-import { WithNotes } from '../notes-addon';
+import withNotes from '../notes-addon';
 
 import Button from './Button';
 
 storiesOf('Button', module)
-  .add('with text', () => (
-    <WithNotes notes={'This is a very simple Button and you can click on it.'}>
-      <Button onClick={action('clicked')}>Hello Button</Button>
-    </WithNotes>
-  ))
-  .add('with some emojies', () => (
-    <WithNotes notes={'Here we use emojies as the Button text. Doesn&apos;t it look nice?'}>
-      <Button onClick={action('clicked')}><span role="img" aria-label="so cool">😀 😎 👍 💯</span></Button>
-    </WithNotes>
-  ));
+  .addDecorator(withNotes)
+  .add('with text', () => <Button onClick={action('clicked')}>Hello Button</Button>, {
+    notes: 'This is a very simple Button and you can click on it.',
+  })
+  .add(
+    'with some emoji',
+    () => (
+      <Button onClick={action('clicked')}>
+        <span role="img" aria-label="so cool">
+          😀 😎 👍 💯
+        </span>
+      </Button>
+    ),
+    { notes: 'Here we use some emoji as the Button text. Doesn&apos;t it look nice?' }
+  );
 ```
 
 ## Styling your addon

lib/addons/src/make-decorator.js

@@ -15,6 +15,7 @@ export const makeDecorator = ({
   parameterName,
   wrapper,
   skipIfNoParametersOrOptions = false,
+  allowDeprecatedUsage = false,
 }) => {
   const decorator = options => (getStory, context) => {
     const parameters = context.parameters && context.parameters[parameterName];
@@ -44,11 +45,17 @@ export const makeDecorator = ({
         return decorator(...args)(...innerArgs);
       }
 
-      // Used to wrap a story directly .add('story', decorator(options)(() => <Story />))
-      //   This is now deprecated:
-      return deprecate(
-        context => decorator(...args)(innerArgs[0], context),
-        `Passing stories directly into ${name}() is deprecated, instead use addDecorator(${name}) and pass options with the '${parameterName}' parameter`
+      if (allowDeprecatedUsage) {
+        // Used to wrap a story directly .add('story', decorator(options)(() => <Story />))
+        //   This is now deprecated:
+        return deprecate(
+          context => decorator(...args)(innerArgs[0], context),
+          `Passing stories directly into ${name}() is deprecated, instead use addDecorator(${name}) and pass options with the '${parameterName}' parameter`
+        );
+      }
+
+      throw new Error(
+        `Passing stories directly into ${name}() is not allowed, instead use addDecorator(${name}) and pass options with the '${parameterName}' parameter`
       );
     };
   };

lib/addons/src/make-decorator.test.js

@@ -103,10 +103,15 @@ describe('makeDecorator', () => {
     expect(story).toHaveBeenCalled();
   });
 
-  it('passes options added at story time, but with a deprecation warning', () => {
+  it('passes options added at story time, but with a deprecation warning, if allowed', () => {
     deprecatedFns = [];
     const wrapper = jest.fn();
-    const decorator = makeDecorator({ wrapper, name: 'test', parameterName: 'test' });
+    const decorator = makeDecorator({
+      wrapper,
+      name: 'test',
+      parameterName: 'test',
+      allowDeprecatedUsage: true,
+    });
     const options = 'test-val';
     const story = jest.fn();
     const decoratedStory = decorator(options)(story);
@@ -121,4 +126,17 @@ describe('makeDecorator', () => {
     });
     expect(deprecatedFns[0].deprecatedFn).toHaveBeenCalled();
   });
+
+  it('throws if options are added at storytime, if not allowed', () => {
+    const wrapper = jest.fn();
+    const decorator = makeDecorator({
+      wrapper,
+      name: 'test',
+      parameterName: 'test',
+      allowDeprecatedUsage: false,
+    });
+    const options = 'test-val';
+    const story = jest.fn();
+    expect(() => decorator(options)(story)).toThrow(/not allowed/);
+  });
 });