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Actions |
The actions addon is used to display data received by event handler (callback) arguments in your stories.
Actions work via supplying special Storybook-generated “action” arguments (referred to as "args" for short) to your stories. There are two ways to get an action arg:
The recommended way to write actions is to use the fn utility from @storybook/test to mock and spy args. This is very useful for writing interaction tests. You can mock your component's methods by assigning them to the fn() function:
<CodeSnippets paths={[ 'angular/button-story-onclick-action-spy.ts.mdx', 'common/button-story-onclick-action-spy.js.mdx', 'common/button-story-onclick-action-spy.ts.mdx', ]} />
If your component calls an arg (because of either the user's interaction or the play function) and that arg is spied on , the event will show up in the action panel:
Another option is to use a global parameter to match all argTypes that match a certain pattern. The following configuration automatically creates actions for each on argType (which you can either specify manually or can be inferred automatically).
This is quite useful when your component has dozens (or hundreds) of methods and you do not want to manually apply the fn utility for each of those methods. However, this is not the recommended way of writing actions. That's because automatically inferred args are not available as spies in your play function. If you use argTypesRegex and your stories have play functions, you will need to also define args with the fn utility to test them in your play function.
<CodeSnippets paths={[ 'common/storybook-preview-matching-argtypes.js.mdx', 'common/storybook-preview-matching-argtypes.ts.mdx', ]} />
If you need more granular control over which argTypes are matched, you can adjust your stories and include the argTypesRegex parameter. For example:
<CodeSnippets paths={[ 'angular/button-story-matching-argtypes.ts.mdx', 'web-components/button-story-matching-argtypes.js.mdx', 'web-components/button-story-matching-argtypes.ts.mdx', 'common/button-story-matching-argtypes.js.mdx', 'common/button-story-matching-argtypes.ts.mdx', ]} />
If you're generating argTypes with another addon (like docs, which is the common behavior), ensure the actions addon AFTER the other addon. You can do this by listing it later in the addons registration code in .storybook/main.js. This is default in essentials.
It is also possible to detect if your component is emitting the correct HTML events using the parameters.actions.handles parameter.
<CodeSnippets paths={[ 'angular/button-story-action-event-handle.ts.mdx', 'web-components/button-story-action-event-handle.js.mdx', 'web-components/button-story-action-event-handle.ts.mdx', 'common/button-story-action-event-handle.js.mdx', 'common/button-story-action-event-handle.ts.mdx', ]} />
This will bind a standard HTML event handler to the outermost HTML element rendered by your component and trigger an action when the event is called for a given selector. The format is <eventname> <selector>. The selector is optional; it defaults to all elements.
This addon contributes the following parameters to Storybook, under the actions namespace:
Type: string
Create actions for each arg that matches the regex. Please note the significant limitations of this approach, as described above.
Type: boolean
Disable this addon's behavior. If you wish to disable this addon for the entire Storybook, you should do so when registering addon-essentials. See the essential addon's docs for more information.
This parameter is most useful to allow overriding at more specific levels. For example, if this parameter is set to true at the project level, it could then be re-enabled by setting it to false at the meta (component) or story level.
Type: string[]
Binds a standard HTML event handler to the outermost HTML element rendered by your component and triggers an action when the event is called for a given selector. The format is <eventname> <selector>. The selector is optional; it defaults to all elements.
See the action event handlers section, above, for more information.
This addon contributes the following exports to Storybook:
import { action } from '@storybook/addon-actions';Type: (name?: string) => void
Allows you to create an action that appears in the actions panel of the Storybook UI when clicked. The action function takes an optional name parameter, which is used to identify the action in the UI.
<CodeSnippets paths={[ 'angular/addon-actions-action-function.ts.mdx', 'web-components/addon-actions-action-function.js.mdx', 'web-components/addon-actions-action-function.ts.mdx', 'common/addon-actions-action-function.js.mdx', 'common/addon-actions-action-function.ts.mdx', ]} />
There are also some older ways to use actions as documented in the advanced README.