ORKGraphChartViewDataSource Protocol Reference
Conforms to  NSObject 

Declared in  ORKGraphChartView.h 
An object that adopts the ORKGraphChartViewDataSource
protocol is responsible for providing the
data required to populate an ORKGraphChartView
object.
At a minimum, a data source object must implement the graphChartView:numberOfPointsInPlot:
and
graphChartView:plot:valueForPointAtIndex:
methods. These methods return
the number of points in a plot and the points themselves. Each point in a plot is represented by an
object of the ORKRangedPoint
class. A data source object may provide additional information to
the graph chart view by implementing the optional methods.
When configuring an ORKGraphChartView
object, assign your data source to its dataSource
property.
– graphChartView:numberOfPointsForPlotIndex:
required method
Asks the data source for the number of range points to be plotted by the graph chart view at the specified plot index.
 (NSInteger)graphChartView:(ORKGraphChartView *)graphChartView numberOfPointsForPlotIndex:(NSInteger)plotIndex
Parameters
graphChartView 
The graph chart view asking for the number of range points. 

plotIndex 
An index number identifying the plot in the graph chart view. This index is 0 in a singleplot graph chart view. 
Return Value
The number of range points in the plot at plotIndex
.
Declared In
ORKGraphChartView.h
– graphChartView:pointForPointIndex:plotIndex:
required method
Asks the data source for the range point to be plotted at the specified point index for the specified plot.
 (ORKRangedPoint *)graphChartView:(ORKGraphChartView *)graphChartView pointForPointIndex:(NSInteger)pointIndex plotIndex:(NSInteger)plotIndex
Parameters
graphChartView 
The graph chart view that is asking for the range point. 

pointIndex 
An index number identifying the range point in the graph chart view. 
plotIndex 
An index number identifying the plot in the graph chart view. This index is 0 in a singleplot graph chart view. 
Return Value
The range point specified by pointIndex
in the plot specified by plotIndex
for the
specified graph chart view`.
Declared In
ORKGraphChartView.h
– numberOfPlotsInGraphChartView:
Asks the data source for the number of plots to be plotted by the graph chart view. If this method is not implemented, the graph chart view assumes that it has a single plot.
 (NSInteger)numberOfPlotsInGraphChartView:(ORKGraphChartView *)graphChartView
Parameters
graphChartView 
The graph chart view asking for the number of plots. 

Return Value
The number of plots in the graph chart view.
Declared In
ORKGraphChartView.h
– graphChartView:colorForPlotIndex:
Asks the data source for the color of the specified plot.
 (UIColor *)graphChartView:(ORKGraphChartView *)graphChartView colorForPlotIndex:(NSInteger)plotIndex
Parameters
graphChartView 
The graph chart view asking for the color of the segment. 

plotIndex 
An index number identifying the plot in the graph chart view. This index is always 0 in singleplot graph chart views. 
Return Value
The color of the segment at the specified index in a pie chart view.
Discussion
If this method is not implemented, the first plot uses the graph chart view tintColor
, and
all subsequent plots uses the current referenceLineColor
.
Declared In
ORKGraphChartView.h
– scrubbingPlotIndexForGraphChartView:
Asks the data source which plot the scrubber should snap to in multigraph chart views.
 (NSInteger)scrubbingPlotIndexForGraphChartView:(ORKGraphChartView *)graphChartView
Parameters
graphChartView 
The graph chart view asking for the scrubbing plot index. 

Return Value
The index of the plot that the scrubber should snap to.
Discussion
If this method is not implemented, the scrubber snaps over the first plot.
Declared In
ORKGraphChartView.h
– maximumValueForGraphChartView:
Asks the data source for the upper limit of the yaxis drawn by the graph chart view.
 (CGFloat)maximumValueForGraphChartView:(ORKGraphChartView *)graphChartView
Parameters
graphChartView 
The graph chart view asking for the maximum value. 

Return Value
The maximum value of the yaxis drawn by graphChartView
.
Discussion
If this method is not implemented, the greatest maximumValue
of all ORKRangedPoint
instances
returned in graphChartView:plot:valueForPointAtIndex:
is used.
See also: graphChartView:plot:valueForPointAtIndex:
.
Declared In
ORKGraphChartView.h
– minimumValueForGraphChartView:
Asks the data source for the lower limit of the yaxis drawn by the graph chart view.
 (CGFloat)minimumValueForGraphChartView:(ORKGraphChartView *)graphChartView
Parameters
graphChartView 
The graph chart view asking for the minimum value. 

Return Value
The minimum value of the yaxis drawn by graphChartView
.
Discussion
If this method is not implemented, the smallest minimumValue
of all ORKRangedPoint instances
returned in graphChartView:plot:valueForPointAtIndex:
is used.
See also: graphChartView:plot:valueForPointAtIndex:
.
Declared In
ORKGraphChartView.h
– numberOfDivisionsInXAxisForGraphChartView:
Asks the data source for the number of divisions in the xaxis. The value is ignored if it is lower
than the number of data points. A title appearing adjacent to each
division may optionally be returned by the graphChartView:titleForXAxisAtPointIndex:
method.
 (NSInteger)numberOfDivisionsInXAxisForGraphChartView:(ORKGraphChartView *)graphChartView
Parameters
graphChartView 
The graph chart view asking for the number of divisions in its xaxis. 

Return Value
The number of divisions in the xaxis for graphChartView
.
Declared In
ORKGraphChartView.h
– graphChartView:titleForXAxisAtPointIndex:
Asks the data source for the title to be displayed adjacent to each division in the xaxis (the
number returned by numberOfDivisionsInXAxisForGraphChartView:
). You can return nil
from this
method if you don’t want to display a title for the specified point index.
 (nullable NSString *)graphChartView:(ORKGraphChartView *)graphChartView titleForXAxisAtPointIndex:(NSInteger)pointIndex
Parameters
graphChartView 
The graph chart view asking for the title. 

pointIndex 
The index of the specified xaxis division. 
Return Value
The title string to be displayed adjacent to each division of the xaxis of the graph chart view.
Discussion
If this method is not implemented, the xaxis has no titles.
See also: numberOfDivisionsInXAxisForGraphChartView:
.
Declared In
ORKGraphChartView.h
– graphChartView:drawsVerticalReferenceLineAtPointIndex:
Asks the data source if the vertical reference line at the specified point index should be drawn..
 (BOOL)graphChartView:(ORKGraphChartView *)graphChartView drawsVerticalReferenceLineAtPointIndex:(NSInteger)pointIndex
Parameters
graphChartView 
The graph view asking for the tile. 

pointIndex 
The index corresponding to the number returned by

Return Value
Whether the graph chart view should draw the vertical reference line.
Discussion
If this method is not implemented, the graph chart view will draw all vertical reference lines.
Declared In
ORKGraphChartView.h