Conforms to NSObject
Declared in IGAsyncCategoryDataSourceHelper.h

Overview

This protocol provides methods to set up and interact with the async data source helper. These methods alow the data to be loaded on demand asynchronously into the chart. The interface that conforms to this protocol must implement at least the two required methods.

Tasks

Instance Methods

beginAsyncDataSourceRequest:

Notifies the user that an async request has started.

- (void)beginAsyncDataSourceRequest:(IGAsyncCategoryDataSourceHelper *)dataSourceHelper

Parameters

dataSourceHelper

Reference to the data source helper.

Declared In

IGAsyncCategoryDataSourceHelper.h

endAsyncDataSourceRequest:

Notifies the user that an async request has ended.

- (void)endAsyncDataSourceRequest:(IGAsyncCategoryDataSourceHelper *)dataSourceHelper

Parameters

dataSourceHelper

Reference to the data source helper.

Declared In

IGAsyncCategoryDataSourceHelper.h

numberOfPointsInAsyncDataSourceHelper:series:

Specifies the total number of points in the data source. The chart uses the return value to determine to total range of data.

- (NSInteger)numberOfPointsInAsyncDataSourceHelper:(IGAsyncCategoryDataSourceHelper *)dataSourceHelper series:(IGSeries *)series

Parameters

dataSourceHelper

Reference to the async data source helper.

series

The series using the async data source.

Return Value

Total number of points used in the data source.

Declared In

IGAsyncCategoryDataSourceHelper.h

provideValuesAtStartIndex:endIndex:forAsyncDataSourceHelper:series:

Returns a range of business objects to be used by the chart as data. The returned array is used to fill a buffer around the chart and is a subset of the total data. The actual visible data is a subset of the returned array. ValuePath and labelPath properties will extract value and label pairs from the business object.

- (NSArray *)provideValuesAtStartIndex:(NSInteger)startIndex endIndex:(NSInteger)endIndex forAsyncDataSourceHelper:(IGAsyncCategoryDataSourceHelper *)dataSourceHelper series:(IGSeries *)series

Parameters

startIndex

Start index used to fetch data.

endIndex

End index used to fetch data.

dataSourceHelper

Reference to the data source helper.

series

The series using the async data source.

Return Value

An array of business objects that will be used as data for the chart.

Declared In

IGAsyncCategoryDataSourceHelper.h

viewForAsyncDataSourceLoadIndicator:

Provides a UIView to be used as a load indicator when the data is being loaded. If this method isn’t implemented, the chart will use a default UIActivityIndicator.

- (UIView *)viewForAsyncDataSourceLoadIndicator:(IGAsyncCategoryDataSourceHelper *)dataSourceHelper

Parameters

dataSourceHelper

Reference to the data source helper.

Return Value

A view to be used as a load indicator.

Declared In

IGAsyncCategoryDataSourceHelper.h