Class: DeferredDataProvider

Oracle® JavaScript Extension Toolkit (JET)
5.2.0
E97691-01

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

DeferredDataProvider

Version:

5.2.0

Since:

4.2.0

Module:

ojdeferreddataprovider

This class implements oj.DataProvider. This object represents a data provider that is created with deferred data and can be used by any component that requires a data provider that will be created with data from a Promise.

Constructor

new DeferredDataProvider(dataProvider, capabilityFunc)

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

Parameters:

Name	Type	Description
`dataProvider`	Promise.<oj.DataProvider>	A promise that resolves to an oj.DataProvider
`capabilityFunc`	function	An function that implements oj.DataProvider#getCapability.

Example

// DeferredDataProvider is used in cases where the data for the data provider will be
// provided asynchronously. In the example below, let getDeferredData() be any function
// that returns a Promise that will resolve to the final data.
var deferredDataPromise = getDeferredData();

// Create a Promise that will resolve to a data provider containing the resolved data
var dataProviderPromise = deferredDataPromise.then(function(resolvedData){
 return new oj.ArrayDataProvider(resolvedData);
});

// Then create a DeferredDataProvider object with the promise that will resolve to a data provider,
// and an implemenation of oj.DataProvider#getCapability
var dataprovider = new oj.DeferredDataProvider(dataProviderPromise, capabilityFunc);

Methods

addEventListener(eventType, listener)

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

Parameters:

Name	Type	Description
`eventType`	string	The event type to add listener to.
`listener`	EventListener	The event listener to add.

containsKeys(params) → {Promise.<oj.ContainsKeysResults>}

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

Check if there are rows containing the specified keys

Parameters:

Name	Type	Description
`params`	oj.FetchByKeysParameters	Fetch by keys parameters

Returns:

Promise which resolves to oj.ContainsKeysResults

Type: Promise.<oj.ContainsKeysResults>

dispatchEvent(evt) → {boolean}

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

Parameters:

Name	Type	Description
`evt`	Event	The event to dispatch.

Returns:

false if the deferred data provider has not resolved or the event has been cancelled, and true otherwise.

Type: boolean

fetchByKeys(params) → {Promise.<oj.FetchByKeysResults>}

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

Fetch rows by keys

Parameters:

Name	Type	Description
`params`	oj.FetchByKeysParameters	Fetch by keys parameters

Returns:

Promise which resolves to oj.FetchByKeysResults

Type: Promise.<oj.FetchByKeysResults>

fetchByOffset(params) → {Promise.<oj.FetchByOffsetResults>}

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

Fetch rows by offset

Parameters:

Name	Type	Description
`params`	oj.FetchByOffsetParameters	Fetch by offset parameters

Returns:

Promise which resolves to oj.FetchByOffsetResults

Type: Promise.<oj.FetchByOffsetResults>

fetchFirst(params) → {AsyncIterable.<oj.FetchListResult>}

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

Fetch the first block of data.

Parameters:

Name	Type	Argument	Description
`params`	oj.FetchListParameters	<optional>	Fetch parameters

See:

https://github.com/tc39/proposal-async-iteration for further information on AsyncIterable.

Returns:

AsyncIterable with oj.FetchListResult

Type: AsyncIterable.<oj.FetchListResult>

getCapability(capabilityName) → {Object}

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

Determines whether this DataProvider supports certain feature.

Parameters:

Name	Type	Description
`capabilityName`	string	capability name. Supported capability names are: "fetchByKeys", "fetchByOffset", and "sort"

Returns:

capability information or null if unsupported

Type: Object

getTotalSize() → {Promise.<number>}

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

Return the total number of rows in this dataprovider

Returns:

Returns a Promise which resolves to the total number of rows. -1 is unknown row count.

Type: Promise.<number>

isEmpty() → {"yes"|"no"|"unknown"}

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

Return a string that indicates if this data provider is empty

Returns:

a string that indicates if this data provider is empty. Valid values are: "yes": this data provider is empty. "no": this data provider is not empty. "unknown": it is not known if this data provider is empty until it has resolved, and a fetch is made.

Type: "yes" | "no" | "unknown"

removeEventListener(eventType, listener)

PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.

Parameters:

Name	Type	Description
`eventType`	string	The event type to remove listener from.
`listener`	EventListener	The event listener to remove.