Usage
Signature:
final class MutableArrayDataProvider<K, D> implements DataProvider<K, D>
Generic Parameters
Parameter Description K Type of Key D Type of Data
Typescript Import Format
//This class is exported directly as module. To import it
import MutableArrayDataProvider= require("ojs/ojmutablearraydataprovider");
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 MutableArrayDataProvider(data, options)
Parameters:
Name | Type | Argument | Description | ||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
data |
Array |
<optional> |
data supported by the components.
If the data array is frozen, it will be used by MutableArrayDataProvider directly. If it is not frozen, MutableArrayDataProvider will make a shallow copy and use the copy. Mutations to the original array will not be reflected in MutableArrayDataProvider. The only way to mutate the data in MutableArrayDataProvider is by setting the "data" property to another array. |
||||||||||||||||||||
options |
Object |
<optional> |
Options for the MutableArrayDataProvider
Properties
|
Example
// First initialize an array
let deptArray = [{DepartmentId: 10, DepartmentName: 'Administration', LocationId: 200},
{DepartmentId: 20, DepartmentName: 'Marketing', LocationId: 200},
{DepartmentId: 30, DepartmentName: 'Purchasing', LocationId: 200}];
// Then create an MutableArrayDataProvider object with the array
let dataprovider = new MutableArrayDataProvider(deptArray, {keyAttributes: 'DepartmentId'});
Fields
-
data
-
The underlying data array.
Applications can get and set this property directly, such as setting it to a different array.
The array returned by the "data" property is frozen. Applications cannot call array mutation methods such as splice or push on "data" directly. Applications need to make a copy of the array, mutate the copy, and set it back into the "data" property.
When setting this property, MutableArrayDataProvider will shallow compare the new data array with the existing data array to determine if it can fire "mutate" event with add/remove/update details. It will fire the "refresh" event if it cannot make that determination (e.g. if the two arrays are vastly different.)
- Since:
- 10.0.0
Properties:
Name Type data
Array.<D>
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'); }
-
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 empty key Map
// 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 empty key Set
// 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.
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:
-
- https://github.com/tc39/proposal-async-iteration for further information on AsyncIterable.
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- If capabilityName is "fetchByKeys", returns a FetchByKeysCapability object.
- If capabilityName is "fetchByOffset", returns a FetchByOffsetCapability object.
- If capabilityName is "sort", returns a SortCapability object.
- If capabilityName is "filter", returns a FilterCapability object.
- If capabilityName is "fetchCapability", returns a FetchCapability object.
- 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 ...
-
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.