@ergosign/storybook-addon-pseudo-states-angular NP

Storybook Addon Pseudo States

Storybook Addon Pseudo States allows you to automatically display pseudo states (and attribute states) of a component in Storybook's preview area.

Live-Demo
Example Repo (Angular CI)

example

Framework Support

Framework	Display States	Tool-Button to show/hide
Angular	+	+
React	+	+
Lit	+	+
HTML	+	+
Vue	+	+

Getting started

First of all, you need to install Pseudo States into your project as a dev dependency.

npm install @ergosign/storybook-addon-pseudo-states-angular --save-dev

Then, configure it as an addon by adding it to your main.js file (located in the Storybook config directory).

To display the pseudo states, you have to add specific css classes to your styling, see Styling

Then, you can set the decorator locally, see Usage.

Styling

Automatically generated with PostCss Webpack config (recommended)

Preset-Postcss adds postcss-loader to Storybook's custom webpack config.

You must also install postcss-pseudo-classes. Unfortunately, latest version is only tagged and not released. Please use at least tagged version 0.3.0

npm install postcss-pseudo-classes@0.3.0 --save-dev

Then add the preset preset-postcss to your configuration in main.js (located in the Storybook config directory):

main.js;

module.exports = {
  presets: ['@ergosign/storybook-addon-pseudo-states-angular/preset-postcss'],
};

This creates for each css pseudo class an equivalent as normal css class (for instance :hover to \:hover), so that you can use it in element's class attribute (<div class=":hover">Element in hover state</div>).

You can modify post css loader options (see type definition of PseudoStatesPresetOptions):

module.exports = {
   presets: [
       {
            name:"@ergosign/storybook-addon-pseudo-states-angular/preset-postcss",
            options: {
                rules: [/\.scss$|\.sass$/, ".sass", ...],
                cssLoaderOptions: CssLoaderOptions,
                postCssLoaderPseudoClassesPluginOptions: {
                    prefix: 'pseudo-sates--', // default for angular
                    blacklist: [':nth-child', ':nth-of-type']
                }
            }
        }     
    ] 
}

It's not recommended to alter the prefix option. But if you need to be change the prefix then it must not start with : because Angular's scoping put scope's context before each colon and breaks styling.

If you set another prefix you have to set the same for the addon, too. Therefore, add the following to your .storybook/preview.js:

addParameters({
    withPseudo: {
        prefix: "still-pseudo-states--",
    },
});

Show/Hide Toolbar-Button

You can enable a toolbar button that toggles the Pseudo States in the Preview area.

See Framework Support which Frameworks support this feature.

Enable the button by adding it to your main.js file (located in the Storybook config directory):

// main.js

module.exports = {
  addons: ['@ergosign/storybook-addon-pseudo-states-angular/register'],
};

Usage

WARNING: withPseudo should always the first element in your decorators array because it alters the template of the story.

Component Story Format (CSF, recommended)

The component field is required because it is used by the addon to register the component to an internal used module (Module Metadata declarations).

import { withPseudo } from '@ergosign/storybook-addon-pseudo-states-angular';

const section = {
  component: ButtonComponent,
  title: 'Button',
  moduleMetadata: {
    declarations: [ButtonComponent],
    imports: [CommonModule],
  },
  decorators: [withPseudo()],
  parameters: {
    // <button> is a ViewChild of ButtonComponent
    withPseudo: { selector: 'button' },
  },
};
export default section;

export const Story = () => {
  return {
    component: ButtonComponent,
    moduleMetadata: {
      declarations: [ButtonComponent],
      imports: [CommonModule],
    },
    // ButtonComponent has same properties as props' keys
    props: {
      label: 'Test Label',
      anotherProperty: true,
    },
  };
};

export const StoryWithTemplate = () => {
  return {
    // always provide component!
    component: ButtonComponent,
    moduleMetadata: {
      entryComponents: [ButtonComponent], // required to support other addons, like knobs addon
      declarations: [ButtonComponent],
      imports: [CommonModule],
    },
    template: `<test-button [label]="label" [anotherProperty]="anotherProperty"></test-button>`,
    props: {
      label: 'Test Label',
      anotherProperty: true,
    },
  };
};

storyOf Format

import { withPseudo } from '@ergosign/storybook-addon-pseudo-states-angular';

storiesOf('Button', module)
  .addDecorator(withPseudo)
  .addParameters({
    withPseudo: {
      selector: 'button', // css selector of pseudo state's host element
      pseudos: ['focus', 'hover', 'hover & focus', 'active'],
      attributes: ['disabled', 'readonly', 'error'],
    },
  })
  .add('Icon Button', () => <Button />);

There is a default configuration for selector, pseudos and attributes. Thus, you can leave withPseudo options empty.

Attributes & Permutations

You can display the component in an attribute/@Inputs state by adding the attribute name (and value) to attributes option.

The permutations option displays the component in each pseudo (from pseudos) and attribute (from attributes) state mixed with the applied attribute added to permutations option.

import { withPseudo } from '@ergosign/storybook-addon-pseudo-states-angular';

const section = {
  component: ButtonComponent,
  title: 'Button',
  moduleMetadata: {
    declarations: [ButtonComponent],
    imports: [CommonModule],
  },
  decorators: [withPseudo()],
  parameters: {
    withPseudo: { selector: 'button' },
    pseudos: ['focus', 'hover', 'hover & focus', 'active'],
    attributes: ['disabled', 'readonly'],
    permutations: [
        'error', // applied default value is true
        {
            label: "Light theme",
            name: "theme", // @Input name
            value: "dark"
        }
    ]
  },
};
export default section;

export const Story = () => {
  return {
    component: ButtonComponent,
    moduleMetadata: {
      declarations: [ButtonComponent],
      imports: [CommonModule],
    },
    // ButtonComponent has same properties as props' keys
    props: {
      label: 'Test Label',
      anotherProperty: true,
    },
  };
};