Question

I have 4 files, BarPlot.h and BarPlot.m, BarPlotViewController.h and BarPlotViewController.m
and my(probably very straight forward to you guys)is I cant get the BarplotViewController to display my graph.

I’ve made sure that the correct view controller is being called in the storyboard.

I’ve gone over the code multiple times but I just cant figure out why the view is not showing up when I run the app in simulator..

I have included the files below.

Any and all help is greatly appreciated.

BarPlotViewController.h

#import <UIKit/UIKit.h>
#import "CorePlot-CocoaTouch.h"
#import "BarPlot.h"

@interface BarPlotViewController : UIViewController {
    CPTGraphHostingView *_graphHostingView;
}

@property (nonatomic, retain) BarPlot *barPlot;

@end

BarPlotViewController.m

#import "BarPlotViewController.h"

@implementation BarPlotViewController
@synthesize barPlot = _barPlot;


- (void)viewWillAppear:(BOOL)animated
{   
    self.barPlot = [[BarPlot alloc] initWithHostingView:_graphHostingView];
    [self.barPlot generateBarPlot];
}

@end

BarPlot.h

#import <UIKit/UIKit.h>
#import "CorePlot-CocoaTouch.h"

@interface BarPlot : UIViewController <CPTBarPlotDataSource, CPTBarPlotDelegate> {
    CPTGraphHostingView *_hostingView;  
CPTXYGraph *_graph;
}

@property (nonatomic, retain) NSMutableArray *data;
@property (nonatomic, retain) CPTGraphHostingView *hostingView;
@property (nonatomic, retain) CPTXYGraph *graph;


// Methods to create this object and attach it to it's hosting view.
-(id)initWithHostingView:(CPTGraphHostingView *)hostingView;


// Generate the bar plot
- (void) generateBarPlot;

@end

BarPlot.m

#import "BarPlot.h"

@implementation BarPlot

#define BAR_POSITION @"POSITION"
#define BAR_HEIGHT @"HEIGHT"
#define COLOR @"COLOR"
#define CATEGORY @"CATEGORY"

#define AXIS_START 0
#define AXIS_END 50

@synthesize data;
@synthesize hostingView = _hostingView;
@synthesize graph = _graph;


// Initialise the bar plot in the provided hosting
-(id)initWithHostingView:(CPTGraphHostingView *)hostingView
{
    self = [super init];

if ( self != nil ) {
    self.hostingView = hostingView;
    self.graph = nil;
}


NSLog(@"Bar Plot: I'm in the initWithHostingView (in the barplot.m file)");

return self;
}


- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {

    self.data = [NSMutableArray array];

    int bar_heights[] = {20,30};


    UIColor *colors[] = {
        [UIColor redColor],
        [UIColor blueColor],
        [UIColor orangeColor],
        [UIColor purpleColor]};


    NSString *categories[] = {@"", @""};



    for (int i = 0; i < 2 ; i++){
        double position = i*20; //Bars will be 10 pts away from each other
        double height = bar_heights[i];

        NSDictionary *bar = [NSDictionary dictionaryWithObjectsAndKeys:
                             [NSNumber numberWithDouble:position],BAR_POSITION,
                             [NSNumber numberWithDouble:height],BAR_HEIGHT,
                             colors[i],COLOR,
                             categories[i],CATEGORY,
                             nil];
        [self.data addObject:bar];

    }
    [self generateBarPlot];
}
return self;
}


- (void)generateBarPlot
{
//Create host view
/*self.hostingView = [[CPTGraphHostingView alloc] 
                    initWithFrame:[[UIScreen mainScreen]bounds]];
[self.view addSubview:self.hostingView];



//Create graph and set it as host view's graph
self.graph = [[CPTXYGraph alloc] initWithFrame:self.hostingView.bounds];
[self.hostingView setHostedGraph:self.graph];*/



// Create a graph object which we will use to host just one scatter plot.
CGRect frame = [self.hostingView bounds];
self.graph = [[CPTXYGraph alloc] initWithFrame:frame];

// Tie the graph we've created with the hosting view.
self.hostingView.hostedGraph = self.graph;



//set graph padding and theme
self.graph.plotAreaFrame.paddingTop = 20.0f;
self.graph.plotAreaFrame.paddingRight = 20.0f;
self.graph.plotAreaFrame.paddingBottom = 70.0f;
self.graph.plotAreaFrame.paddingLeft = 70.0f;
[self.graph applyTheme:[CPTTheme themeNamed:kCPTDarkGradientTheme]];



// Gets rid of decimal on years
NSNumberFormatter *labelFormatter = [[NSNumberFormatter alloc] init];
labelFormatter.maximumFractionDigits = 0;



//set axes ranges
CPTXYPlotSpace *plotSpace = (CPTXYPlotSpace *)self.graph.defaultPlotSpace;
plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:
                    CPTDecimalFromFloat(AXIS_START)
                                                length:CPTDecimalFromFloat((AXIS_END - AXIS_START))];
plotSpace.yRange = [CPTPlotRange plotRangeWithLocation:
                    CPTDecimalFromFloat(AXIS_START)
                                                length:CPTDecimalFromFloat((AXIS_END - AXIS_START))];




CPTXYAxisSet *axisSet = (CPTXYAxisSet *)self.graph.axisSet;
//set axes' title, labels and their text styles
CPTMutableTextStyle *textStyle = [CPTMutableTextStyle textStyle];
textStyle.fontName = @"Helvetica";
textStyle.fontSize = 14;
textStyle.color = [CPTColor whiteColor];



axisSet.xAxis.title = @"A";
axisSet.yAxis.title = @"B";
axisSet.xAxis.titleTextStyle = textStyle;
axisSet.yAxis.titleTextStyle = textStyle;
axisSet.xAxis.titleOffset = 30.0f;
axisSet.yAxis.titleOffset = 40.0f;
axisSet.xAxis.labelTextStyle = textStyle;
axisSet.yAxis.labelTextStyle = textStyle;
axisSet.xAxis.labelOffset = 3.0f;
axisSet.yAxis.labelOffset = 3.0f;



//set axes' line styles and interval ticks
CPTMutableLineStyle *lineStyle = [CPTMutableLineStyle lineStyle];
lineStyle.lineColor = [CPTColor whiteColor];
lineStyle.lineWidth = 3.0f;
axisSet.xAxis.axisLineStyle = lineStyle;
axisSet.yAxis.axisLineStyle = lineStyle;
axisSet.xAxis.majorTickLineStyle = lineStyle;
axisSet.yAxis.majorTickLineStyle = lineStyle;
axisSet.xAxis.majorIntervalLength = CPTDecimalFromFloat(5.0f);
axisSet.yAxis.majorIntervalLength = CPTDecimalFromFloat(5.0f);
axisSet.xAxis.majorTickLength = 10.0f;
axisSet.yAxis.majorTickLength = 10.0f;
axisSet.xAxis.minorTickLineStyle = lineStyle;
axisSet.yAxis.minorTickLineStyle = lineStyle;
axisSet.xAxis.minorTicksPerInterval = 1;
axisSet.yAxis.minorTicksPerInterval = 1;
axisSet.xAxis.minorTickLength = .0f;
axisSet.yAxis.minorTickLength = .0f;
axisSet.xAxis.labelFormatter = labelFormatter;
axisSet.yAxis.labelFormatter = labelFormatter;



// Create bar plot and add it to the graph
CPTBarPlot *plot = [[CPTBarPlot alloc] init] ;
plot.delegate = self;
plot.dataSource = self;
plot.barWidth = [[NSDecimalNumber decimalNumberWithString:@"5.0"]
                 decimalValue];
plot.barOffset = [[NSDecimalNumber decimalNumberWithString:@"10.0"]
                  decimalValue];
plot.barCornerRadius = 5.0;



// Remove bar outlines
CPTMutableLineStyle *borderLineStyle = [CPTMutableLineStyle lineStyle];
borderLineStyle.lineColor = [CPTColor clearColor];
plot.lineStyle = borderLineStyle;



// Identifiers are handy if you want multiple plots in one graph
plot.identifier = @"chocoplot";
[self.graph addPlot:plot];
}



-(NSUInteger)numberOfRecordsForPlot:(CPTPlot *)plot
{
if ( [plot.identifier isEqual:@"chocoplot"] ) 
{
    return [self.data count];
}

return 0;
}



-(NSNumber *)numberForPlot:(CPTPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index
{
if ( [plot.identifier isEqual:@"chocoplot"] )
{

    NSDictionary *bar = [self.data objectAtIndex:index];


    if( fieldEnum == 2 ) {
        return [bar valueForKey:BAR_POSITION];
        //return [NSNumber numberWithDouble:20];
    }
    else if( fieldEnum == 3 ) {
        return [bar valueForKey:BAR_HEIGHT];
        //return [NSNumber numberWithDouble:20];
    }

}
NSLog(@"numberForPlot return before");
return [NSNumber numberWithDouble:15];
}

@end

Answer 1

Well, the first thing I notice is that you never call addSubview. That’s the code that actually “adds the view”, so I’d start there. Also, see this question, the second answer looks like it might help: Adding CPTGraphHostingView as a subview