Element: <oj-conveyor-belt>

Oracle® JavaScript Extension Toolkit (JET)
17.0.0
F92240-01

Since:
  • 0.6.0
Module:
  • ojconveyorbelt

Note: This component is in maintenance mode. Suggested alternative: <oj-c-conveyor-belt>. For help updating an existing application, see the migration section.

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JET ConveyorBelt

Description: Container element that manages overflow for its child elements and allows scrolling among them.

Child elements of the ConveyorBelt must all be siblings at the same level. The size of the ConveyorBelt must somehow be constrained in order for there to be overflow to manage, for example by specifying CSS max-width or max-height.

If the elements to be scrolled among are direct children of the ConveyorBelt, then ConveyorBelt will ensure that they are laid out appropriately for its orientation. However, if the elements to be scrolled among are contained by a single nested descendant element, the content-parent, then it is up to calling code to ensure that the elements are laid out appropriately. For example, elements can be forced horizontal by using CSS white-space:nowrap, or vertical by using display:block. 


<oj-conveyor-belt>
  <oj-button>Alpha</oj-button>
  <oj-button>Beta</oj-button>
  <oj-button>Gamma</oj-button>
  <oj-button>Delta</oj-button>
  <oj-button>Epsilon</oj-button>
  <oj-button>Zeta</oj-button>
</oj-conveyor-belt>

JET FilmStrip and ConveyorBelt look similar, but are intended to be used for different purposes.

Use ConveyorBelt when you want to:

  • handle overflow without showing a scrollbar
  • keep all items accessible via tabbing and readable by a screen reader

Use FilmStrip when you want to:

  • layout a set of items across discrete logical pages
  • control which and how many items are shown
  • hide items outside the current viewport from tab order and screen reader

Touch End User Information

Target Gesture Action
ConveyorBelt Swipe Transition to an adjacent logical page of child items.
Navigation Arrow Tap Transition to an adjacent logical page of child items.

Keyboard End User Information

If tabindex=0 ConveyorBelt supports the following keyboard interactions:

Target Key Action
ConveyorBelt RightArrow or DownArrow Scrolls the content Right/Down.
ConveyorBelt LeftArrow or UpArrow Scrolls the content Left/Up

Keyboard Application Developer Information

Providing keyboard support for the items in the conveyor belt is the responsibility of the application developer, if the items do not already support keyboard interaction. This could be done, for example, by specifying tabindex on each item to enable tab navigation. Alternatively, this could be done by adding a keyboard listener and responding to key events, like pressing the arrow keys.

Accessibility

ConveyorBelt provides opt-in keyboard accessibility. To be able to scroll using keyboard, it is required to set attribute tabindex=0. If Sighted keyboard-only users also need to be able to access the items in the conveyor just by using the keyboard. It is up to the child items of the ConveyorBelt to support keyboard navigation. If child items support tab navigation, the browser may scroll them into view when they receive focus. If child items support other forms of keyboard navigation, for example by using the arrow keys, it is up to the child items to scroll themselves into view. This may be done, for example, by calling the DOM function focus() or scrollIntoView() on the item. ConveyorBelt will be aware of tab based or programmatic scrolling and will honor it, updating itself to toggle visibility of the overflow indicators as needed.

Migration

Read about current Core Pack limitations to decide when to migrate.
Please make note of the following:

To migrate from oj-conveyor-belt to oj-c-conveyor-belt, you need to revise the import statement and references to oj-c-conveyor-belt in your app. Please note the changes between the two components below.
    The new oj-c-conveyor-belt component could be in two modes:
  • A ConveyorBelt component with completely opaque content. The navigation by arrows always scroll by fixed size, i.e. width of the scroll view port. The snapping position is not applied and the scrolling could be stopped so that child element is visible partially.
  • Items aware ConveyorBelt component. A ConveyorBelt component that contains information about its children/items. The navigation by keyboard right/left arrows scrolls and snaps the child elements to the best fit. To make conveyor belt aware of its content please use items attribute and template element with itemTemplate slot.
content-parent attribute

The content-parent attribute is no longer supported.

items attribute

The items attribute is the new way to provide data to make the new oj-c-conveyor-belt component to be aware of its items. Besides maintaining its support for DataProvider, the items attribute also accepts an Array of data items. The items attribute only works in connection with itemTemplate slot. The itemTemplate slot is used to specify the template for rendering each item in the Conveyor Belt. The slot content must be a <template> element.

itemTemplate slot

The itemTemplate slot is used to specify the template for rendering each item in the Conveyor Belt. The slot content must be a <template> element. Please specify items attribute if conveyor belt items need data. The itemTemplate and items makes conveyor belt component to be aware of its items and respect individual items borders during pagination.

refresh method

The refresh() method is no longer supported. The application should no longer need to use this method.

oj-bind-for-each operator

It is recommended that the items attribute is used instead of oj-bind-for-each operator

Reading direction

As with any JET element, in the unusual case that the directionality (LTR or RTL) changes post-init, the conveyorBelt must be refresh()ed.


Usage

Signature:

interface ConveyorBeltElement

Typescript Import Format
//To typecheck the element APIs, import as below.
import { ConveyorBeltElement } from "ojs/ojconveyorbelt";

//For the transpiled javascript to load the element's module, import as below
import "ojs/ojconveyorbelt";

For additional information visit:

Note: Application logic should not interact with the component's properties or invoke its methods until the BusyContext indicates that the component is ready for interaction.


Styling

CSS Variables

See JET CSS Variables for additional details.
Name Type Description
--oj-conveyor-belt-box-shadow-width <length> Conveyor belt box-shadow width

Slots

JET components that allow child content support slots. Please see the slots section of the JET component overview doc for more information on allowed slot content and slot types.

Default

The <oj-conveyor-belt> element manages overflow for its child elements and allows scrolling among them. Child elements of the <oj-conveyor-belt> must all be siblings at the same level.

If the elements to be scrolled among are nested descendants and not direct children of the conveyor belt, the content-parent attribute should specify the nested elements direct parent.

contextMenu

The contextMenu slot is set on the oj-menu within this element. This is used to designate the JET Menu that this component should launch as a context menu on right-click, Shift-F10, Press & Hold, or component-specific gesture. If specified, the browser's native context menu will be replaced by the JET Menu specified in this slot.

The application can register a listener for the Menu's ojBeforeOpen event. The listener can cancel the launch via event.preventDefault(), or it can customize the menu contents by editing the menu DOM directly, and then calling refresh() on the Menu.

To help determine whether it's appropriate to cancel the launch or customize the menu, the ojBeforeOpen listener can use component API's to determine which table cell, chart item, etc., is the target of the context menu. See the JSDoc of the individual components for details.

Keep in mind that any such logic must work whether the context menu was launched via right-click, Shift-F10, Press & Hold, or component-specific touch gesture.

Deprecated:
Since Description
13.0.0 This web component no longer supports launching a context menu.

Attributes

arrow-visibility :"auto"|"visible"|"hidden"

Indicates whether overflow content arrows are visible or hidden.

The default value of this property varies by theme. If the default value is 'auto', then the behavior varies by device.

Supported Values:
Value Description
auto show overflow arrows on desktop, hide on mobile.
hidden never show overflow arrows.
visible always show overflow arrows.
Supports writeback:
  • true
Since:
  • 9.0.0
Names
Item Name
Property arrowVisibility
Property change event arrowVisibilityChanged
Property change listener attribute (must be of type function, see Events and Listeners for additional information.) on-arrow-visibility-changed

(nullable) content-parent :string

Specify the selector of the descendant DOM element in the conveyorBelt that directly contains the items to scroll among.

This attribute value is null by default, meaning that the items to scroll among are direct children of the oj-conveyor-belt. In some cases, the items to scroll among are not direct children of the oj-conveyor-belt, but are instead nested in a descendant DOM element. In such cases, this attribute should be specified to point to the descendant DOM element whose direct children are the items to scroll among. For example, if the items to scroll among are buttons in a buttonset, the buttons are direct children of the DOM element representing the buttonset. The buttonset would be the direct child of the conveyorBelt. If the id of the buttonset DOM element were 'myContentElem', then content-parent would be specified as '#myContentElem'.

WARNING: The selector specified for this attribute should match only a single descendant DOM element. If multiple elements are matched, then only the first one will be used. Applications should not depend on this behavior because we reserve the right to change it in the future in order to allow and use multiple matching elements.

Default Value:
  • null
Supports writeback:
  • true
Names
Item Name
Property contentParent
Property change event contentParentChanged
Property change listener attribute (must be of type function, see Events and Listeners for additional information.) on-content-parent-changed

orientation :"horizontal"|"vertical"

Specify the orientation of the conveyorBelt.
Supported Values:
Value Description
horizontal Orient the conveyorBelt horizontally.
vertical Orient the conveyorBelt vertically.
Default Value:
  • "horizontal"
Supports writeback:
  • true
Names
Item Name
Property orientation
Property change event orientationChanged
Property change listener attribute (must be of type function, see Events and Listeners for additional information.) on-orientation-changed

scroll-position :number

Gets or sets the number of pixels that an element's content is scrolled from its initial position.

The default value of this property is 0.

There is no difference between LTR/RTL value assignment. In both LTR and RTL values changes from 0 and max scroll position >=0 if we scroll to the end. If we scroll to the beginning then the values changes from max scroll position >=0 to min scroll position = 0 When the value exceeds max/min the value is constrained to the max/min scroll position accordingly.

Default Value:
  • 0
Supports writeback:
  • true
Since:
  • 12.0.0
Names
Item Name
Property scrollPosition
Property change event scrollPositionChanged
Property change listener attribute (must be of type function, see Events and Listeners for additional information.) on-scroll-position-changed

translations :object|null

A collection of translated resources from the translation bundle, or null if this component has no resources. Resources may be accessed and overridden individually or collectively, as seen in the examples.

If the component does not contain any translatable resource, the default value of this attribute will be null. If not, an object containing all resources relevant to the component.

If this component has translations, their documentation immediately follows this doc entry.

Names
Item Name
Property translations
Property change event translationsChanged
Property change listener attribute (must be of type function, see Events and Listeners for additional information.) on-translations-changed

(nullable) translations.tip-arrow-next :string

Tooltip for the next overflow content arrow.

See the translations attribute for usage examples.

Default Value:
  • "Next"
Since:
  • 10.0.0
Names
Item Name
Property translations.tipArrowNext

(nullable) translations.tip-arrow-previous :string

Tooltip for the previous overflow content arrow.

See the translations attribute for usage examples.

Default Value:
  • "Previous"
Since:
  • 10.0.0
Names
Item Name
Property translations.tipArrowPrevious

Methods

getProperty(property) : {any}

Retrieves the value of a property or a subproperty. The return type will be the same as the type of the property as specified in this API document. If the method is invoked with an incorrect property/subproperty name, it returns undefined.
Parameters:
Name Type Description
property string The property name to get. Supports dot notation for subproperty access.
Since:
  • 4.0.0
Returns:
Type
any
Example

Get a single subproperty of a complex property:

let subpropValue = myComponent.getProperty('complexProperty.subProperty1.subProperty2');

refresh : {void}

Refreshes the visual state of the conveyorBelt. JET elements require a refresh() after the DOM is programmatically changed underneath the element.

This method does not accept any arguments.

Returns:
Type
void

scrollElementIntoView(elem) : {void}

Scrolls child item of conveyor belt into the view.
Parameters:
Name Type Description
elem Element DOM element to scroll
Since:
  • 9.0.0
Returns:
Type
void

setProperties(properties) : {void}

Performs a batch set of properties. The type of value for each property being set must match the type of the property as specified in this API document.
Parameters:
Name Type Description
properties Object An object containing the property and value pairs to set.
Since:
  • 4.0.0
Returns:
Type
void
Example

Set a batch of properties:

myComponent.setProperties({"prop1": "value1", "prop2.subprop": "value2", "prop3": "value3"});

setProperty(property, value) : {void}

Sets a property or a subproperty (of a complex property) and notifies the component of the change, triggering a [property]Changed event. The value should be of the same type as the type of the attribute mentioned in this API document.
Parameters:
Name Type Description
property string The property name to set. Supports dot notation for subproperty access.
value any The new value to set the property to.
Since:
  • 4.0.0
Returns:
Type
void
Example

Set a single subproperty of a complex property:

myComponent.setProperty('complexProperty.subProperty1.subProperty2', "someValue");