https://github.com/brightspaceui/d2l-polymer-behaviors-ui
Shared Polymer behaviors for use in web components
https://github.com/brightspaceui/d2l-polymer-behaviors-ui
browser polymer web-components
Last synced: 5 months ago
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Shared Polymer behaviors for use in web components
- Host: GitHub
- URL: https://github.com/brightspaceui/d2l-polymer-behaviors-ui
- Owner: BrightspaceUI
- License: apache-2.0
- Created: 2016-06-30T20:44:19.000Z (almost 10 years ago)
- Default Branch: main
- Last Pushed: 2024-05-21T18:11:36.000Z (about 2 years ago)
- Last Synced: 2024-11-15T22:58:38.507Z (over 1 year ago)
- Topics: browser, polymer, web-components
- Language: JavaScript
- Size: 195 KB
- Stars: 0
- Watchers: 18
- Forks: 9
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Codeowners: CODEOWNERS
Awesome Lists containing this project
README
# @brightspace-ui/polymer-behaviors
Shared [Polymer](https://www.polymer-project.org/1.0/)-based behaviors and modules for implementing and consuming web components.
## Installation
Install from NPM:
```shell
npm install @brightspace-ui/polymer-behaviors
```
## Usage
#### Methods
**D2L.Dom**
```javascript
// returns null or the closest ancestor that fulfills the specified predicate fxn
D2L.Dom.findComposedAncestor(node, predicate);
// gets the composed children (including shadow children & distributed children)
D2L.Dom.getComposedChildren(element);
// gets the composed parent (including shadow host & insertion points)
D2L.Dom.getComposedParent(node);
// returns true/false whether the specified ancestorNode is an ancestor of node
D2L.Dom.isComposedAncestor(ancestorNode, node);
// browser consistent implementation of HTMLElement.offsetParent
D2L.Dom.getOffsetParent(node);
```
**D2L.Dom.Focus**
```javascript
// get the composed active element (i.e. the actual element that has focus)
D2L.Dom.Focus.getComposedActiveElement();
// get first focusable child or descendant
D2L.Dom.Focus.getFirstFocusableDescendant(element);
// get last focusable child or descendant
D2L.Dom.Focus.getLastFocusableDescendant(element);
// get the next focusable child, sibling, etc.
D2L.Dom.Focus.getNextFocusable(element);
// get the previous focusable child, sibling, etc.
D2L.Dom.Focus.getPreviousFocusable(element);
// get the nearest focusable ancestor
D2L.Dom.Focus.getPreviousFocusableAncestor(element);
// check is focusable (tabindex or white-listed elements)
D2L.Dom.Focus.isFocusable(element);
```
**D2L.Dom.Visibility**
```javascript
// checks DOM visibility (includes inline & computed style of element and ancestors)
// ... does not check opacity, elements hidden due to overflow or scrolled out of view
D2L.Dom.Visibility.isVisible(element);
```
**D2L.Id**
```javascript
// gets a unique indexed id (for lifetime of page)
D2L.Id.getUniqueId();
```
#### Behaviors
**D2L.PolymerBehaviors.FocusableArrowKeysBehavior**
The `FocusableArrowKeysBehavior` can be used for managing focus with the arrow keys.
* right/down - focuses next element, or first if currently at the end
* left/up - focuses previous element, or last if currently at beginning
* home - focuses first
* end - focuses last
```javascript
// include the behavior
behaviors: [
D2L.PolymerBehaviors.FocusableArrowKeysBehavior
],
attached: function() {
Polymer.RenderStatus.afterNextRender(this, function() {
// indicate the direction (default is leftright)
this.arrowKeyFocusablesDirection = 'updown';
// required container element of focusables (used to listen for key events)
this.arrowKeyFocusablesContainer = container;
// required provider method that can return list of focusables - possible async
this.arrowKeyFocusablesProvider = function() {
// simple case
return Promise.resolve(focusables);
// other cases (ex. check visibility when querying focusables)
return new Promise(function(resolve) {
fastdom.measure(function() {
// ...
resolve(focusables);
});
});
};
// optional callback before focus is applied
this.arrowKeyFocusablesOnBeforeFocus = function(elem) {
return new Promise(function(resolve) {
// do some stuff
resolve();
});
};
});
}
```
**D2L.PolymerBehaviors.VisibleOnAncestorBehavior**
The `VisibleOnAncestorBehavior` can be used to show an element when a specified ancestor is being hovered, or a child of the ancestor has the focus. Likewise, the element will be hidden if the specified ancestor is not being hovered and none of its children have the focus. To define a component with this behavior, simply include the styles and behavior as shown in the example below.
```html
Polymer({
is: 'd2l-example',
behaviors: [
D2L.PolymerBehaviors.VisibleOnAncestorBehavior
]
});
```
The consumer of `d2l-example` adds the `d2l-visible-on-ancestor-target` class to the desired ancestor that will be the target for mouse and focus events. If the user hovers the target, or focuses any element contained within, `d2l-example` will be displayed.
```html
...
...
```
### Versioning and Releasing
This repo is configured to use `semantic-release`. Commits prefixed with `fix:` and `feat:` will trigger patch and minor releases when merged to `main`.
To learn how to create major releases and release from maintenance branches, refer to the [semantic-release GitHub Action](https://github.com/BrightspaceUI/actions/tree/main/semantic-release) documentation.