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:
-
- 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 ...
-
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