<ia-dropdown> web component

Usage

import { optionInterface } from 'src/ia-dropdown';
const options = [{
  id: 'option-1',
  url: 'https://example.com',
  selectedHandler: (option: optionInterface) => alert(option.id),
  label: html`
    <ia-icon-label>
      <i slot="icon" class="invert-icon-at-hover">?</i>
      <span>Ask Question</span>
    </ia-icon-label>
  `
}]

<ia-dropdown
  options=${options}
  displayCaret
  @optionSelected=${({ detail }) => console.log('changed', detail.option )}
>
  <p id="custom trigger" slot="dropdown-label">Click me to toggle options</p>
</ia-dropdown>

<ia-dropdown> public properties

• open controls whether the dropdown menu is currently visible
  • default: false
• isDisabled controls whether the main button and/or caret is disabled
  • default: false
• displayCaret controls whether the dropdown caret should be present
  • default: false
• closeOnSelect controls whether selecting an option in the dropdown menu should close it
  • default: false
• openViaButton controls whether clicking on the main button (not including the caret) should open the dropdown menu
  • default: true
• openViaCaret controls whether clicking on the main button's caret (if present) should open the dropdown menu
  • default: true
• includeSelectedOption controls whether the currently-selected option is included in the dropdown menu
  • default: false
• options specifies the list of items available in the dropdown menu, using the structure shown above. Only id and label are required.
  • default: []
  • Other menu option types can be used by setting isCustomList to true and using the list slot with a custom list component.
• selectedOption is a string specifying the id of the currently-selected option
  • default: ''
• optionGroup is a string describing the dropdown's purpose, accessible to screen-readers only
  • default: options
•  isCustomList replaces default option list with slot list allowing a custom list component to be used with different option type and behavior
  • default: false
•  hasCustomClickHandler controls whether mainbutton @click event overridden by ancestor @click or custom event
  • default: false
•  closeOnEscape controls whether the dropdown menu should close when the escape key is pressed
  • default: false
•  closeOnBackdropClick controls whether the dropdown menu should close when the backdrop is clicked
  • default: false

<ia-dropdown> slots

• slot="dropdown-label" the main button that opens the dropdown menu.
• slot="caret-up" replaces default up caret svg.
  • Use both slot="caret-up" and class="caret-up-svg" in the <svg>.
• slot="caret-down" replaces default down caret svg.
  • Use both slot="caret-down" and class="caret-down-svg" in the <svg>.
• slot="list" allows replacing default dropdown menu option type and behavior.

<ia-dropdown> events

Listens for:

• closeDropdown closes the dropdown menu

Dispatches:

• optionSelected when an option is selected in the dropdown menu

<ia-dropdown> CSS

CSS Vars Primary:

• var(--dropdownFontSize, 1rem)
• var(--dropdownTextColor, #fff)
• var(--dropdownBgColor, #333)
• var(--dropdownCaretColor, #fff)
• var(--dropdownBorderColor, #fff)
• var(--dropdownBorderWidth, 1px)
  • Or override with: --dropdownBorderTopWidth (similarly for Right, Bottom, and Left)
• var(--dropdownBorderRadius, 4px)
  • Or override with --dropdownBorderTopLeftRadius (similarly for TopRight, BottomRight, and BottomLeft)
• var(--dropdownOffsetTop, 5px) (vertical distance between main button and dropdown)
• var(--dropdownButtonPadding, 0)
• var(--dropdownWhiteSpace, normal) (NB: setting to nowrap allows the dropdown to exceed the main button's width)

Selected:

• var(--dropdownSelectedBgColor, #fff)
• var(--dropdownSelectedTextColor, #2c2c2c)

Hover:

• var(--dropdownHoverBgColor, #fff)
• var(--dropdownHoverTextColor, #2c2f2c)
• var(--dropdownHoverTopBottomBorderColor, #333)

Dropdown list position:

• var(--dropdownListPosition, absolute) (dropdown pops up over content)
• var(--dropdownListPosition, relative) (dropdown accordians with content)

Dropdown list z-index:

• var(--dropdownListZIndex, 1)

Dropdown item padding:

• var(--dropdownItemPaddingTop, 5px) (similarly for Right, Bottom, and Left)

Main button:

• var(--dropdownMainButtonPadding, 0px)
• var(--dropdownMainButtonBorder, none)
• var(--dropdownMainButtonBorderRadius, none)
• var(--dropdownMainButtonFlexDirection, row) (Setting to column allows vertical layout)
• var(--dropdownMainButtonHoverBgColor, inherit)
• var(--dropdownMainButtonFocusBgColor, inherit)
• var(--dropdownMainButtonActiveBgColor, inherit)

Caret:

• var(--caretWidth, 20px)
• var(--caretHeight, 10px)
• var(--caretPadding, 0)

<ia-icon-label> CSS

Top Level Classes

• .invert-icon-at-hover
  • applies filter: invert(1) to icon in slot[name='icon'] on label hover
• .invert-icon-at-selected
  • applies filter: invert(1) to icon in slot[name='icon'] when the element has .selected class. <ia-icon-label class="selected invert-icon-at-selected">

ex.

<ia-icon-label class="selected invert-icon-at-hover invert-icon-at-selected">
  <i slot="icon" class="my-icon"></i> <!-- <i/> gets `filter: invert(1)` -->
  <span>my label</span>
</ia-icon-label>

Child Classes

• truncate
  • applies text-overflow: ellipsis to text in children of unnamed slot which use this class
  • applies -webkit-line-clamp: 2 if supported by browser

CSS Vars

• var(--iconWidth, 20px)
• var(--iconHeight, 20px)
• var(--iconLabelGutterWidth, 10px)
• var(--hoverTextColor, #2c2c2c)
• var(--hoverBGColor, #fff)
• var(--selectedBgColor, #fff)
• var(--selectedTextColor, #2c2c2c)
• var(--iconLabelGutterWidth, 10px)
• var(--iconLabelFlexDirection, row) (setting to column allows vertical layout)

Local Demo with web-dev-server

yarn start

To run a local development server that serves the basic demo located in demo/index.html

Testing with Web Test Runner

To run the suite of Web Test Runner tests, run

yarn run test

To run the tests in watch mode (for <abbr title="test driven development">TDD</abbr>, for example), run

yarn run test:watch

Linting with ESLint, Prettier, and Types

To scan the project for linting errors, run

yarn run lint

You can lint with ESLint and Prettier individually as well

yarn run lint:eslint

yarn run lint:prettier

To automatically fix many linting errors, run

yarn run format

You can format using ESLint and Prettier individually as well

yarn run format:eslint

yarn run format:prettier

Tooling configs

For most of the tools, the configuration is in the package.json to reduce the amount of files in your project.

If you customize the configuration a lot, you can consider moving them to individual files.