ReferencesStrategy

StrategyBaseConverter Class

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Definition

A custom TypeConverter class handling the designed behavior of a strategy’s property descriptor collection. Use this as a base class for any custom TypeConverter you are applying to a strategy class.

Notes:

Relevant base methods

MethodDescription
TypeConverter.GetProperties()When overriding GetProperties(), calling base.GetProperties() ensures that all default property grid behavior works as designed
TypeConverter.GetPropertiesSupported()In your custom converter class, you must override GetPropertiesSupported() and return a value of true in order for your custom type converter to work

Syntax

public class StrategyBaseConverter : TypeConverter

Failure to apply a type of StrategyBaseConverter on a strategy class can result in unpredictable behavior of the standard NinjaTrader WPF property grid.

Tip: Common strategy functions like Print() are not available to a type converter instance. To debug a type converter class, you can use the AddOn Debug Concepts or attach to a debugger (recommended)

Examples

1// This namespace holds Strategies in this folder and is required. Do not change it.
2namespace NinjaTrader.NinjaScript.Strategies
3{
4   // When applying the type converter, you must fully qualify the name
5   [TypeConverter("NinjaTrader.NinjaScript.Strategies.MyCustomConveter")]
6   public class MyCustomStrategy : Strategy
7   {
8     protected override void OnStateChange()
9     {
10         if (State == State.SetDefaults)
11         {
12           Name                             = "MyCustomStrategy";
13         }
14     }
15
16     protected override void OnBarUpdate()
17     {
18         //Add your custom strategy logic here.
19     }
20   }
21
22   // custom converter class for strategies
23   public class MyCustomConveter : StrategyBaseConverter
24   {
25     // A general TypeConveter method used for converting types
26     public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext context, object component, Attribute[] attrs)
27     {
28         // sometimes you may need the strategy instance which actually exists on the grid
29         MyCustomStrategy strategy = component as MyCustomStrategy;
30
31         // base.GetProperties ensures we have all the properties (and associated property grid editors)
32         // NinjaTrader internal logic handles for a given strategy
33         PropertyDescriptorCollection propertyDescriptorCollection = base.GetPropertiesSupported(context)
34                 ? base.GetProperties(context, component, attrs) : TypeDescriptor.GetProperties(component, attrs);
35
36         if (strategy == null || propertyDescriptorCollection == null)
37           return propertyDescriptorCollection;
38
39         // example of why you may need the instance that exists on the grid....
40         if (strategy.EntryHandling == EntryHandling.UniqueEntries)
41         {
42           // do something in the event a property contains some value...
43         }
44
45         // Loop all of the properties of the strategy
46         foreach (PropertyDescriptor property in propertyDescriptorCollection)
47         {
48           // do something with a specific property
49
50           // cannot call **Print()** here
51           // but you can call the static Output window "Process()"
52           NinjaTrader.Code.Output.Process(property.Name, PrintTo.OutputTab1);
53         }
54
55         // must return the collection after making changes
56         return propertyDescriptorCollection;
57     }
58
59     // Important:  This must return true otherwise the type converter will not be called
60     public override bool GetPropertiesSupported(ITypeDescriptorContext context)
61     { return true; }
62   }
63}