Usage
Signature:
final class FlattenedTreeDataProviderView<K, D> implements DataProvider<K, D>
Generic Parameters
Parameter Description K Type of output key D Type of output data
Typescript Import Format
//This class is exported directly as module. To import it
import FlattenedTreeDataProviderView= require("ojs/ojflattenedtreedataproviderview");
For additional information visit:
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.
Constructor
new FlattenedTreeDataProviderView(dataProvider, options)
Parameters:
Name | Type | Argument | Description |
---|---|---|---|
dataProvider |
TreeDataProvider.<K, D> | the wrapped TreeDataProvider to flatten. | |
options |
FlattenedTreeDataProviderView.Options.<K> |
<optional> |
Options for FlattenedTreeDataProviderView |
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
let keySet = new Set(); keySet.add(1001); keySet.add(556); let value = await dataprovider.containsKeys({keys: keySet}); let results = value['results']; if (results.has(1001)) { console.log('Has key 1001'); } else if (results.has(556)) { console.log('Has key 556'); }
-
createOptimizedKeyMap(initialMap?: Map<K, D>): Map<K, D>
-
Return an empty Map which is optimized to store key value pairs
Optionally provided by certain DataProvider implementations for storing key/value pairs from the DataProvider in a performant fashion. Sometimes components will need to temporarily store a Map of keys provided by the DataProvider, for example, in the case of maintaining a Map of selected keys. Only the DataProvider is aware of the internal structure of keys such as whether they are primitives, Strings, or objects and how to do identity comparisons. Therefore, the DataProvider can optionally provide a Map implementation which can performantly store key/value pairs surfaced by the DataProvider.
Parameters:
Name Type Argument Description initialMap
Map.<any> <optional>
Optionally specify an initial map of key/values for the Map. If not specified, then return an empty Map. - Since:
- 6.2.0
Returns:
Returns a Map optimized for handling keys from the DataProvider.
- Type
- Map.<any>
Example
// create optional parameter let initMap = new Map(); initMap.set('a', 'apple'); let keyMap = dataprovider.createOptimizedKeyMap(initMap);
-
createOptimizedKeySet(initialSet?: Set<K>): Set<K>
-
Return an empty Set which is optimized to store keys
Optionally provided by certain DataProvider implementations for storing keys from the DataProvider in a performant fashion. Sometimes components will need to temporarily store a Set of keys provided by the DataProvider, for example, in the case of maintaining a Set of selected keys. Only the DataProvider is aware of the internal structure of keys such as whether they are primitives, Strings, or objects and how to do identity comparisons. Therefore, the DataProvider can optionally provide a Set implementation which can performantly store keys surfaced by the DataProvider.
Parameters:
Name Type Argument Description initialSet
Set.<any> <optional>
Optionally specify an initial set of keys for the Set. If not specified, then return an empty Set. - Since:
- 6.2.0
Returns:
Returns a Set optimized for handling keys from the DataProvider.
- Type
- Set.<any>
Example
// create optional initial parameter let initSet = new Set(); initSet.add('a'); let keySet = dataprovider.createOptimizedKeySet(initSet);
-
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. Fetch can be aborted if an AbortSignal is specified when calling fetchByKeys.
Parameters:
Name Type Description parameters
FetchByKeysParameters fetch by key parameters - Since:
- 4.2.0
Returns:
Returns Promise which resolves to FetchByKeysResults.
- Type
- Promise.<FetchByKeysResults>
Examples
let keySet = new Set(); keySet.add(1001); keySet.add(556); let value = await dataprovider.fetchByKeys({keys: keySet}); // get the data for key 1001 console.log(value.results.get(1001).data);
// abort on an AbortController instance will abort all requests that are associated // with the signal from that abortController. const abortController = new AbortController(); let keySet = new Set(); keySet.add(1001); keySet.add(556); // component passes AbortSignal as part of FetchByKeysParameters to fetchByKeys // on dataProvider try { let value = await dataprovider.fetchByKeys({keys: keySet, signal: abortController.signal}); } catch (err) { // if the data fetch has been aborted, retrieving data from the fetched result // will be rejected with DOMException named AbortError if (err.severity === 'info') { // if the data fetch has been aborted from a jet component as a performance concern, an AbortReason will be provided. console.log(err.message); } } // later when abort is desired, component can invoke abort() on the cached // abort controller to abort any outstanding data retrieval it requested // on asyncIterator. if (abort_is_desired) { abortController.abort(); }
-
fetchByOffset(parameters: FetchByOffsetParameters<D>): Promise<FetchByOffsetResults<K, D>>
-
Fetch rows by offset. Fetch can be aborted if an AbortSignal is specified when calling fetchByOffset.
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. If an unsupported matchBy value is included in FetchByOffsetParameters, an error will be thrown. - Since:
- 4.2.0
Returns:
Returns Promise which resolves to FetchByOffsetResults.
- Type
- Promise.<FetchByOffsetResults>
Examples
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']; });
// abort on an AbortController instance will abort all requests that are associated // with the signal from that abortController. const abortController = new AbortController(); // component passes AbortSignal as part of FetchByOffsetParameters to fetchByOffset // on dataProvider try { let value = await dataprovider.fetchByOffset({ size: 5, offset: 2, signal: abortController.signal }); } catch (err) { // if the data fetch has been aborted, retrieving data from the fetched result // will be rejected with DOMException named AbortError if (err.severity === 'info') { // if the data fetch has been aborted from a jet component as a performance concern, an AbortReason will be provided. console.log(err.message); } } // later when abort is desired, component can invoke abort() on the cached // abort controller to abort any outstanding data retrieval it requested // on asyncIterator. if (abort_is_desired) { abortController.abort(); }
-
fetchFirst(parameters?: FetchListParameters<D>): AsyncIterable<FetchListResult<K, D>>
-
Get an AsyncIterable object for iterating the data.
AsyncIterable contains a Symbol.asyncIterator method that returns an AsyncIterator. AsyncIterator contains a “next” method for fetching the next block of data.
The "next" method returns a promise that resolves to an object, which contains a "value" property for the data and a "done" property that is set to true when there is no more data to be fetched. The "done" property should be set to true only if there is no "value" in the result. Note that "done" only reflects whether the iterator is done at the time "next" is called. Future calls to "next" may or may not return more rows for a mutable data source.
Please see the DataProvider documentation for more information on custom implementations.
Parameters:
Name Type Argument Description params
FetchListParameters <optional>
fetch parameters - See:
-
- https://github.com/tc39/proposal-async-iteration for further information on AsyncIterable.
Returns:
AsyncIterable with FetchListResult
- Type
- AsyncIterable.<FetchListResult>
Example
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: "dedup", "eventFiltering", "fetchByKeys", "fetchByOffset", "fetchCapability", "fetchFirst", "filter", and "sort". - Since:
- 4.2.0
Returns:
capability information or null if undefined
- If capabilityName is "dedup", returns a DedupCapability object.
- If capabilityName is "eventFiltering", returns a EventFilteringCapability object.
- If capabilityName is "fetchByKeys", returns a FetchByKeysCapability object.
- If capabilityName is "fetchByOffset", returns a FetchByOffsetCapability object.
- If capabilityName is "fetchCapability", returns a FetchCapability object. (Deprecated since 10.0.0. Use specific fetch capabilityName (fetchByKeys/fetchByOffset/fetchFirst) instead.)
- If capabilityName is "fetchFirst", returns a FetchFirstCapability object.
- If capabilityName is "filter", returns a FilterCapability object.
- If capabilityName is "sort", returns a SortCapability object.
- Type
- Object
Example
let capabilityInfo = dataprovider.getCapability('fetchByKeys'); if (capabilityInfo.implementation == 'iteration') { // the DataProvider supports iteration for fetchByKeys ...
-
getExpandedObservable():{ subscribe( subscriber : ((expanded: {value: KeySet<K>, completionPromise: Promise<any>}) => void) ): {unsubscribe(): void, closed(): boolean}}
-
Get the observable with information about the expanded state to subscribe to. Consumers can call subscribe and unsubscribe to receive changes to the expanded property.
On the first subscribe call, the initial value will be passed to the subscriber.
The observed value is an object with the following properties: value: KeySet - new expanded key set completionPromise?: Promise - resolved after all mutations have fired relevant to the expand/collapse. Example of consumer listening for the "mutate" event type:
expandedObserexpandedObservable = dataprovider.getExpandedObservable(); subscriber = expandedObservable.subscribe(function(detail){ expanded = detail.value; promise = detail.completionPromise; // handle changes }); // unsubscribe later subscriber.unsubscribe();
- See:
-
- https://github.com/tc39/proposal-observable for further information on Observable and Subscription.
Returns:
an object to call subscribe on to receive changes to the expanded property. The subscribe function returns an object to call unsubscribe on.
- Type
- Object
-
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
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
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. -
setExpanded(keySet: KeySet<K>): void
-
Set a new expanded property on the FlattenedTreeDataProviderView.
Parameters:
Name Type Description keySet
KeySet the new key set representing expanded
Type Definitions
-
Options<K>
-
Properties:
Name Type Argument Description expanded
KeySetImpl<K> | AllKeySetImpl.<K> <optional>
Optional key set to track the expansion state. To monitor the expansion state use the getExpandedObvservable method. To update the expansion state use the setExpanded method.