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<sbb-form-field> is intended to be used as a form input wrapper with label and errors.
In this document, "form field" refers to the wrapper component <sbb-form-field> and
"form field control" refers to the component that the <sbb-form-field> is wrapping
(e.g. the input, select, etc.)
The following components are designed to work inside a <sbb-form-field>:
<input><select><sbb-datepicker><sbb-select><sbb-slider><sbb-time-input>
Usage
The examples below show how to render the component:
<sbb-form-field label="Example">
<input />
</sbb-form-field>
<sbb-form-field>
<label>Example</label>
<input />
<sbb-form-error>This field is required!</sbb-form-error>
</sbb-form-field>Label
Either use a <label> or the label attribute to provide a label for a form input. The
<sbb-form-field> will automatically assign the correct id reference between label and input.
When using the floating label and setting the value programmatically to empty or from empty to a specific value,
it's mandatory to call the reset() method of the sbb-form-field to update the state of the floating label.
Error messages
Error messages can be shown under the form field by adding sbb-form-error elements inside the
form field.
Reserve error space
In order to avoid the layout from "jumping" when an error is shown, the option of setting
error-space="reserve" on the <sbb-form-field> will reserve space for a single line of an error
message.
Prefix & Suffix
It is possible to add content as a prefix or suffix in a <sbb-form-field>. This can be done via
the prefix and suffix slots.
<sbb-form-field label="Example">
<sbb-icon slot="prefix" name="pie-small" />
<input />
<sbb-icon slot="suffix" name="circle-information-small" />
</sbb-form-field>Width
By default, the component has a defined width and min-width. However, this behavior can be overridden by setting
the width property to collapse: in this way the component adapts its width to the inner slotted input component.
This is useful, for example, for the sbb-time-input component. However, as the width-styles are exposed to the host,
it's possible to apply any desired width by setting just the width and min-width CSS properties.
Accessibility
By itself, <sbb-form-field> does not apply any additional accessibility treatment to a form
element. However, several of the form field's optional features interact with the form element
contained within the form field.
When you provide a label via <label> or the label attribute, <sbb-form-field> automatically
associates this label with the field's form element via a native <label> element, using the for
attribute to reference the control's ID.
When using a non-native form element (e.g. <sbb-select>) aria-labelledby is used, to connect the
form element with the label, by setting an id on the label and referencing this id in the
aria-labelledby attribute placed on the form element.
Please note that only one <label> element is supported. Additionally, if you place the <label>
element outside the <sbb-form-field>, the automatic assignment is skipped, and it is up to the
consumer to use the correct id references.
When you provide informational text via <sbb-form-error>, <sbb-form-error> automatically adds
these elements' IDs to the form element's aria-describedby attribute. Additionally,
<sbb-form-error> is slotted to an element having aria-live="polite" so that assistive
technology will announce errors when they appear.
Properties
| Property | Attribute | Description | Type | Default |
|---|---|---|---|---|
borderless | borderless | Whether to display the form field without a border. | boolean | false |
errorSpace | error-space | Whether to reserve space for an error message. none does not reserve any space. reserve does reserve one row for an error message. | "none" | "reserve" | 'none' |
floatingLabel | floating-label | Whether the label should float. If activated, the placeholder of the input is hidden. | boolean | false |
label | label | Label text for the input which is internally rendered as <label>. | string | undefined |
optional | optional | Indicates whether the input is optional. | boolean | undefined |
size | size | Size variant, either l or m. | "l" | "m" | 'm' |
width | width | Defines the width of the component: - default: the component has defined width and min-width; - collapse: the component adapts itself to its inner input content. | "collapse" | "default" | 'default' |
Methods
clear() => Promise<void>
Manually clears the input value. It only works for inputs, selects are not supported.
Returns
Type: Promise<void>
getInputElement() => Promise<HTMLInputElement | HTMLSelectElement | HTMLElement>
Returns the input element.
Returns
Type: Promise<HTMLElement | HTMLInputElement | HTMLSelectElement>
reset() => Promise<void>
Manually reset the form field. Currently, this only resets the floating label.
Returns
Type: Promise<void>
Slots
| Slot | Description |
|---|---|
"error" | Slot to render an error. |
"label" | Slot to render a label. |
"prefix" | Slot to render an icon on the left side of the input. |
"suffix" | Slot to render an icon on the right side of the input. |
"unnamed" | Slot to render an input/select. |
Dependencies
Depends on
Graph
graph TD;
sbb-form-field --> sbb-icon
style sbb-form-field fill:#f9f,stroke:#333,stroke-width:4px