This is a very minimal dropdown. That means that it is agnostic about what it is going to contain.
It is intended to be a building block for more complex components but is perfectly usable. It is
by example the addon on which ember-power-select
or ember-paper
's menu component are built upon.
ember install ember-basic-dropdown
If you are using this addon in an application that uses ember-cli-sass, you need to import the styles explicitly.
Add to your app.scss
this line:
@import 'ember-basic-dropdown';
If you are using ember-power-select you don't need any of those steps because you already have this addon :D
This component leverages contextual components for its API:
The yielded dropdown
object is the public API of the component, and contains
properties and actions that you can use to control the component.
{
isOpen: <boolean>,
disabled: <boolean>,
actions: {
open: <action>,
close: <action>,
toggle: <action>,
reposition: <action>
}
}
Check the full documentation with live examples in https://www.ember-basic-dropdown.com
By default this component will render the dropdown in the body using ember-wormhole and absolutely position it to place it in the proper coordinates.
You can opt out to this behavior by passing renderInPlace=true
. That will add the dropdown just
below the trigger.
You don't need to care about adding or removing events, it does that for you.
You can make the dropdown content standout a little more by adding overlay=true
to the content options, see example below. This will add a semi transparent overlay covering the whole screen. Also this will stop bubbling the click/touch event which closed the dropdown.
NOTE: If for some reason clicking outside a dropdown doesn't work, you might want to make sure the <body>
spans the entire viewport. Adding a css rule like body {min-height: 100vh;}
would do the trick. It ensures that wherever you click on the page, it will close the dropdown.
The trigger of the component is focusable by default, and when focused can be triggered using Enter
or Space
.
It also listen to touch events so it works in mobile.
The components provide hooks like onFocus
, onBlur
, onKeydown
, onMouseEnter
and more so
you can do pretty much anything you want.
You can animate it, in an out, with just CSS3 animations. Check the example in the Ember Power Select documentation
This component is smart about where to position the dropdown. It will detect the best place to render it based on the space around the trigger, and also will take care of reposition if if the screen is resized, scrolled, the device changes it orientation or the content of the dropdown changes (implemented with MutationObservers in modern browsers with fallback to DOM events in IE 9/10).
You can force the component to be fixed in one position by passing verticalPosition = above | below
and/or horizontalPosition = right | center | left
.
If even that doesn't match your preferences and you feel brave enough, you can roll your own positioning logic if you pass a calculatePosition
function. It's signature is:
calculatePosition(trigger, dropdown, { previousHorizontalPosition, horizontalPosition, previousVerticalPosition, verticalPosition, matchTriggerWidth })
The return value must be an object with this interface: { horizontalPosition, verticalPosition, styles }
where
where horizontalPosition
is a string ("right" | "center" | "left"
), verticalPosition
is also a string
("above" | "below"
) and styles
is an object with CSS properties, typically top
and left
/right
.
It has a handy collection of test helpers to make interaction with the component seamless in your test suite.