Final Class: PagingDataProviderView

Oracle® JavaScript Extension Toolkit (JET)
9.2.0

F30740-01

Signature:

final class PagingDataProviderView<K, D> implements DataProvider<K, D>, PagingModel

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PagingDataProviderView

Version:
  • 9.2.0
Module:
  • ojpagingdataproviderview

Module usage

See JET Module Loading for an overview of module usage within JET.

Javascript Import Format
define(['ojs/ojpagingdataproviderview'], function(PagingDataProviderView) {
 // Application should call API on PagingDataProviderView 
})
Typescript Import Format
//This class is exported directly as module. To import it
import PagingDataProviderView= require("ojs/ojpagingdataproviderview");

JET In Typescript

A detailed description of working with JET elements and classes in your typescript project can be found at: JET Typescript Usage.

Final classes in JET

Classes in JET are generally final and do not support subclassing. At the moment, final is not enforced. However, this will likely change in an upcoming JET release.

Description

This class implements DataProvider. Wraps a DataProvider to be used with PagingControl. Supports PagingModel API.

Constructor

new PagingDataProviderView(dataProvider)

Parameters:
Name Type Description
dataProvider DataProvider.<K, D> the DataProvider to be wrapped.

This can be either any DataProvider or a wrapped DataSource with a TableDataSourceAdapter. Paging DataProvider View does not handle DataProviders with unknown total sizes.

Methods

addEventListener(eventType: string, listener: EventListener): void

Add a callback function to listen for a specific event type.
Parameters:
Name Type Description
eventType string The event type to listen for.
listener EventListener The callback function that receives the event notification.

containsKeys(parameters : FetchByKeysParameters<K>) : Promise<ContainsKeysResults<K>>

Check if there are rows containing the specified keys. The resulting key map will only contain keys which were actually found.
Parameters:
Name Type Description
parameters FetchByKeysParameters contains by key parameters
Since:
  • 4.2.0
Returns:
Returns Promise which resolves to ContainsKeysResults.
Type
Promise.<ContainsKeysResults>
Example

Check if keys 1001 and 556 are contained

let containsKeys = [1001, 556];
let value = await dataprovider.containsKeys({keys: containsKeys});
let results = value['results'];
if (results.has(1001)) {
  console.log('Has key 1001');
} else if (results.has(556){
  console.log('Has key 556');
}

dispatchEvent(evt: Event): boolean

Dispatch an event and invoke any registered listeners.
Parameters:
Name Type Description
event Event The event object to dispatch.
Returns:
Return false if a registered listener has cancelled the event. Return true otherwise.
Type
boolean

fetchByKeys(parameters : FetchByKeysParameters<K>) : Promise<FetchByKeysResults<K, D>>

Fetch rows by keys. The resulting key map will only contain keys which were actually found.
Parameters:
Name Type Description
parameters FetchByKeysParameters fetch by key parameters
Since:
  • 4.2.0
Returns:
Returns Promise which resolves to FetchByKeysResults.
Type
Promise.<FetchByKeysResults>
Example

Fetch for keys 1001 and 556

let fetchKeys = [1001, 556];
let value = await dataprovider.fetchByKeys({keys: fetchKeys});
// get the data for key 1001
console.log(value.results.get(1001).data);

fetchByOffset(parameters: FetchByOffsetParameters<D>): Promise<FetchByOffsetResults<K, D>>

Fetch rows by offset

A generic implementation of this method is available from FetchByOffsetMixin. It is for convenience and may not provide the most efficient implementation for your data provider. Classes that implement the DataProvider interface are encouraged to provide a more efficient implementation.

Parameters:
Name Type Description
parameters FetchByOffsetParameters fetch by offset parameters
Since:
  • 4.2.0
Returns:
Returns Promise which resolves to FetchByOffsetResults.
Type
Promise.<FetchByOffsetResults>
Example

Fetch by offset 5 rows starting at index 2

let result = await dataprovider.fetchByOffset({size: 5, offset: 2});
let results = result['results'];
let data = results.map(function(value) {
  return value['data'];
});
let keys = results.map(function(value) {
  return value['metadata']['key'];
});

fetchFirst(parameters?: FetchListParameters<D>): AsyncIterable<FetchListResult<K, D>>

Get an asyncIterator which can be used to fetch a block of data.
Parameters:
Name Type Argument Description
params FetchListParameters <optional>
fetch parameters
Since:
  • 4.2.0
See:
Returns:
AsyncIterable with FetchListResult
Type
AsyncIterable.<FetchListResult>
Example

Get an asyncIterator and then fetch first block of data by executing next() on the iterator. Subsequent blocks can be fetched by executing next() again.

let asyncIterator = dataprovider.fetchFirst(options)[Symbol.asyncIterator]();
let result = await asyncIterator.next();
let value = result.value;
let data = value.data;
let keys = value.metadata.map(function(val) {
  return val.key;
});
// true or false for done
let done = result.done;

getCapability(capabilityName: string): any

Determines whether this DataProvider defines a certain feature.
Parameters:
Name Type Description
capabilityName string capability name. Defined capability names are: "fetchByKeys", "fetchByOffset", "sort", "fetchCapability" and "filter".
Since:
  • 4.2.0
Returns:
capability information or null if undefined
Type
Object
Example

Check what kind of fetchByKeys is defined.

let capabilityInfo = dataprovider.getCapability('fetchByKeys');
if (capabilityInfo.implementation == 'iteration') {
  // the DataProvider supports iteration for fetchByKeys
  ...

getEndItemIndex : {number}

Get the current page end index
Returns:
The current page end index
Type
number

getGlobalIndex(value) : {number}

Translates and returns the global index given a local index.
Parameters:
Name Type Description
value number The local index to be translated
Returns:
The translated global index
Type
number

getPage : {number}

Get the current page
Returns:
The current page
Type
number

getPageCount : {number}

Get the page count
Returns:
The total number of pages
Type
number

getStartItemIndex : {number}

Get the current page start index
Returns:
The current page start index
Type
number

getTotalSize : {Promise.<number>}

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>
Example

Get the total rows

let value = await dataprovider.getTotalSize();
if (value == -1) {
  // we don't know the total row count
} else {
  // the total count
  console.log(value);

isEmpty(): 'yes' | 'no' | 'unknown'

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 a fetch is made.
Since:
  • 4.2.0
Returns:
string that indicates if this data provider is empty
Type
"yes" | "no" | "unknown"
Example

Check if empty

let isEmpty = dataprovider.isEmpty();
console.log('DataProvider is empty: ' + isEmpty);

removeEventListener(eventType: string, listener: EventListener): void

Remove a listener previously registered with addEventListener.
Parameters:
Name Type Description
eventType string The event type that the listener was registered for.
listener EventListener The callback function that was registered.

setPage(value, options) : {Promise}

Set the current page. This will trigger a refresh event. During initialization the refresh event is skipped.
Parameters:
Name Type Argument Description
value number The current page
options Object <optional>
Options

pageSize: The page size.

Returns:
promise object triggering done when complete..
Type
Promise

totalSize : {number}

Returns:
total number of items
Type
number

totalSizeConfidence : {string}

Returns the confidence for the totalSize value.
Returns:
"actual" if the totalSize is the time of the fetch is an exact number "estimate" if the totalSize is an estimate "atLeast" if the totalSize is at least a certain number "unknown" if the totalSize is unknown
Type
string