Data sampler

Generates test data: for every message on Input it creates a new record of the output connection's type and fills its properties with (optionally seeded) random values. Use it to exercise a flow without a real data source, for example Timer → Data sampler → the flow under test.

Pins

Pin	Kind	Types	Description
Input	input	any	Trigger. Each message produces one sample; the payload is ignored.
Output	output	the type of the outgoing connection	A new record of that type filled with random values. Set the type on the outgoing connection; it decides what is generated.

Configuration

Field	Type	Default	Description
Seed	string		Seed text. The same seed and the same (sequential) input sequence produce the same data. Empty = different data every run.
NullProbability	integer (0-100)	10	Percent chance that a nullable property (reference types such as string, and Nullable<T>) is set to null. Properties marked required in the type are never null.
NumberMin	number	0	Lower bound for numeric properties.
NumberMax	number	10000	Upper bound for numeric properties.
CollectionMinItems	integer (0-10000)	0	Minimum number of items in generated lists, arrays and dictionaries.
CollectionMaxItems	integer (0-10000)	5	Maximum number of items in generated lists, arrays and dictionaries.

Behaviour

• On start the generator for the output type is built once. If the output pin has no connection/type, nothing is generated and input messages are ignored.
• Generated values:
  • string: 8-32 random letters and digits; char: one letter or digit; bool: random.
  • numbers (byte ... ulong, float, double, decimal): between NumberMin and NumberMax, clamped to the range of the property type.
  • DateTime, DateTimeOffset (UTC), DateOnly: between 1970-01-01 and 2100-01-01; TimeOnly, TimeSpan: within one day.
  • Guid (version 4), IPAddress (IPv4), enums (one of the defined values), byte[].
  • lists, arrays and dictionaries (string or value-type keys) with CollectionMinItems-CollectionMaxItems items; duplicate dictionary keys are dropped.
  • nested complex types are filled recursively up to 4 levels deep; deeper levels are null. The root record is never null.
• Constraints declared on flow type properties are respected: minimum / maximum length for strings and byte[], minimum / maximum value for numbers (the declared range wins over NumberMin / NumberMax if they do not overlap). Regex validators are not honoured (a warning is shown).
• Unsupported property types (object, interfaces, abstract classes, streams, types without a parameterless constructor) are left at their default value with a warning. Read-only and system properties are skipped.
• The metadata of the input message is passed through to the output.

Notes

• NumberMin must not be greater than NumberMax, CollectionMinItems not greater than CollectionMaxItems; otherwise the configuration is rejected. A numeric range that contains no valid value for a property type (for example NumberMax = -1 for a byte property) makes the flow fail to start.
• Reproducibility with Seed holds only for sequential input; parallel callers (Fork, parallel ForEach) interleave the random sequence.

Example

{ "Seed": "test-1", "NullProbability": 0, "NumberMin": 1, "NumberMax": 100, "CollectionMinItems": 1, "CollectionMaxItems": 3 }

Timer → Data sampler (output connection type MyFlow.Order) → Data mapper → ...