CFXDataSourceSettings Class Reference

Discussion

Chart FX supports three different types of data sources:

- You can pass a CFXChartDataSource protocol: you can pass any class that implements the CFXChartDataSource protocol. In many cases, it is the same class that creates the chart.

- You can pass a CoreData object: simply pass a NSFetchedResultsController instance.

- You can pass a collection of objects, such as an NSArray or NSSet.

Once the DataSource has been configured using this property, the chart is automatically bound to the data.

This property has a shortcut called dataSource property and defined in the CFXChart class.

Discussion

Make sure you set the usage for all CFXFieldMaps before reading the data. For example if you have 4 field in your result set, you must make sure 4 assignments are made using this property.

Discussion

Only string data types may be concatenated using the label separator.

If there is a space in the string to be used as a label, the configured label separator will not be appended in the label. Only when two strings are added together will the separator be used.

Discussion

This property is used in conjunction with the fields property to control how Chart FX takes the information from a DataProvider.

Please note that instead of the value associated with the point, you can assign a hidden constant which will cause the point to be hidden in the chart. Although a hidden point is physically in the data array, when you use this constant the marker will not appear in the chart, and if you have charts like a line or area chart, the line will break at that particular point:

chart1.data.y[2,3] = CFXChartHidden;

Chart FX for iOS includes two data style flags that will instruct the component to expect values and X Values or to expect both values and initial values in the data array. For example, lets say that your data looks like this and you want to plot an XY chart:

1 200 3 400

2 100 6 300

When you set the Style to ReadXValues, the data will be passed to the chart like:

chart1.data.x[0,0] = 1;

chart1.data.y[0,0] = 200;

chart1.data.x[1,0] = 3;

chart1.data.y[1,0] = 400;

chart1.data.x[0,1] = 2;

chart1.data.y[0,1] = 100;

chart1.data.x[1,1] = 6;

chart1.data.y[1,1] = 300;

The ReadYFromValues will do the same except it will set initial values using the yFrom property.

Chart FX for iOS willl take all string and date fields to construct a long string that will be used as a legend for each point in the chart. If you want to avoid this behavior, just turn OFF the appropriate constants in this property or control the fields that Chart FX for iOS will use from the Data Source with the DataType property.

Because it is a mask property, you must make sure you use these operators to turn on/off bits and avoid losing previous settings to the property.

For example, if you want to turn on NoMinMax, the right way of setting this property is:

chart1.dataSourceSettings.style = chart1.dataSourceSettings.style | CFXDataSourceStylesNoMinMax;

If you type the following code:

chart1.dataSourceSettings.style = CFXDataSourceStylesNoMinMax;

(WRONG!)

you will erase all other settings in the property causing an erratic behavior of the library and an incorrect setting of the individual methods which also control these flags.