canopy-forms-segment

name	canopy-forms-segment
description	Best practices for the Canopy Segment component. Trigger when adding conscious single-choice selectors, question-and-answer journey controls, or compact radio alternatives in a form in an Angular project using Canopy.
license	MIT
metadata	{"source":"https://github.com/Legal-and-General/canopy/tree/master/projects/canopy/src/lib/forms/radio/docs/segment/guide.mdx"}

Canopy Segment — Best Practices

This skill provides usage guidance, dos and don'ts, and input reference for the Canopy segment control from @legal-and-general/canopy.

Apply this skill whenever you use LgSegmentGroupComponent or LgSegmentButtonComponent.

Segment buttons are implemented as restyled radio buttons. Import LgRadioComponent to use them.

---

Import

import { LgRadioGroupComponent, LgRadioButtonComponent } from '@legal-and-general/canopy';

---

Basic Usage

<lg-segment-group formControlName="colour">
  Colour
  <lg-hint>Select one option</lg-hint>
  <lg-segment-button value="red">Red</lg-segment-button>
  <lg-segment-button value="blue">Blue</lg-segment-button>
  <lg-segment-button value="green">Green</lg-segment-button>
</lg-segment-group>

---

Inputs

LgRadioGroupComponent (used for segment)

Input	Type	Default	Description
id	string	auto-generated	HTML id attribute.
name	string	auto-generated	Sets name on all buttons in the group.
value	boolean | string	null	Default selected value.
focus	boolean	null	Sets focus on the fieldset.
stack	'md' | 'lg'	false	Stacks buttons vertically at the given breakpoint.

LgRadioButtonComponent (used for segment buttons)

Input	Type	Default	Required	Description
name	string	null	Yes	HTML name attribute.
value	string	null	Yes	HTML value attribute.
ariaDescribedBy	string	null	No	ID of describing element.

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Dos and Don'ts

Do

1. Do use when only one option can be selected from 2–5 choices and vertical space is limited.
2. Do use the vertical (stack) variant on mobile when horizontal space is insufficient.

Don't

1. Don't use when multiple items can be selected — use checkboxes instead.
2. Don't use when there are more than 5 options — use the select component instead.

---

Accessibility

• Always use lg-segment-group to group related segment buttons with a clear label.
• Use lg-hint to provide extra context where needed.
• Ensure all segment buttons have clear, descriptive labels.
• There must be clear colour contrast between selected and unselected states.
• Keyboard users use Tab to move into/out of the segment group, and arrow keys to navigate between options and select them (segment buttons are implemented as radios).
• Only one segment button can be selected at a time within a group.

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Design Constraints

• In the default state, nothing is pre-selected (unlike radio buttons, where one is always selected).
• There must be clear colour contrast between the selected and unselected states.
• Use stack="md" or stack="lg" to switch to a vertical layout below a given breakpoint.
• Minimum 2, maximum 5 segment buttons per group.