ArgTypes
ArgTypes are a first-class feature in Storybook for specifying the behaviour of Args. By specifying the type of an arg, you constrain the values that it can take and provide information about args that are not explicitly set (i.e., not required).
You can also use argTypes to “annotate” args with information used by addons that make use of those args. For instance, to instruct the controls addon to render a color, you could choose a string-valued arg.
The most concrete realization of argTypes is the ArgTypes doc block (Controls is similar). Each row in the table corresponds to a single argType and the current value of that arg.
Automatic argType inference
If you are using the Storybook docs addon (installed by default as part of essentials), then Storybook will infer a set of argTypes for each story based on the component specified in the default export of the CSF file.
To do so, Storybook uses various static analysis tools depending on your framework.
- React
- Vue
- Angular
- WebComponents
- Ember
The format of the generated argType will look something like this:
This ArgTypes data structure, name, type, defaultValue, and description are standard fields in all ArgTypes (analogous to PropTypes in React). The table and control fields are addon-specific annotations. So, for example, the table annotation provides extra information to customize how the label gets rendered, and the control annotation includes additional information for the control editing the property.
Manual specification
If you want more control over the args table or any other aspect of using argTypes, you can overwrite the generated argTypes for your component on a per-arg basis. For instance, with the above-inferred argTypes and the following default export:
The values.description, table.type, and controls.type are merged into the defaults extracted by Storybook. The final merged values would be:
In particular, this would render a row with a modified description, a type display with a dropdown that shows the detail, and no control.
Available properties
Here's an explanation of each available property:
| Property | Description |
|---|---|
name | The name of the property. argTypes: { label: { name: 'Something' } } |
type.name | Sets a type for the property. argTypes: { label: { type: { name: 'number' } } } |
type.required | Sets the property as optional or required. argTypes: { label: { type: { required: true } } |
description | Sets a Markdown description for the property. argTypes: { label: { description: 'Something' } } |
table.type.summary | Provide a short version of the type. argTypes: { label: { table: { type: { summary: 'a short summary' } }}} |
table.type.detail | Provides an extended version of the type. argTypes: { label: { table: { type: { detail: 'something' } }}} |
table.defaultValue.summary | Provide a short version of the default value. argTypes: { label: { table: { defaultValue: { summary: 'Hello World' } }}} |
table.defaultValue.detail | Provides a longer version of the default value. argTypes: { label: { table: { defaultValue: { detail: 'Something' } }}} |
control | Associates a control for the property. argTypes: { label: { control: { type: 'text'} } } Read the Essentials documentation to learn more about controls. |
Shorthands
💡 The @storybook/addon-docs provide a shorthand for common tasks:
type: 'number'is shorthand for type: { name: 'number' }control: 'radio'is shorthand for control: { type: 'radio' }
Grouping
You can also manually specify groups to organize related argTypes into categories or even subcategories. Based on the following component implementation:
You could group similar properties for better organization and structure. Using the table below as a reference:
| Field | Category |
|---|---|
| backgroundColor | Colors |
| primary | Colors |
| label | Text |
| onClick | Events |
| size | Sizes |
Results in the following change into your story and UI.
You can also extend the formula above and introduce subcategories, allowing better structuring and organization. Using the table below as a reference leads to the following change to your story and UI:
| Field | Category | Subcategory |
|---|---|---|
| backgroundColor | Colors | Button colors |
| primary | Colors | Button style |
| label | Text | Button contents |
| onClick | Events | Button Events |
| size | Sizes |
Global argTypes
You can also define arg types at the global level; they will apply to every component's stories unless you overwrite them. To do so, export the argTypes key in your preview.js:
Using argTypes in addons
If you want to access the argTypes of the current component inside an addon, you can use the useArgTypes hook from the @storybook/manager-api package: