FluxFlow.Components.Validation 3.0.0

FluxFlow.Components.Validation

A standalone JSON schema validator node for FluxFlow. It depends only on FluxFlow.Nodes — no engine, registry, or runtime. You new the node and LinkTo the next one.

Node

Every message travels as a FlowMessage<T> envelope. The validation result is broadcast on Output as FlowMessage<JsonSchemaValidationResult<TInput>>; the original input is fanned to Valid or Invalid (each FlowMessage<TInput>). All three carry the same correlation id as the input.

var schema = new JsonSchemaValidatorOptions
{
    Schema = JsonSerializer.SerializeToElement(new
    {
        type = "object",
        required = new[] { "id" },
        properties = new { id = new { type = "string" } }
    }),
    SchemaId = "orders"
}.LoadSchema();

await using var node = new JsonSchemaValidatorNode<JsonElement>(schema, schemaId: "orders");

node.Output.LinkTo(resultSink, new DataflowLinkOptions { PropagateCompletion = false });
node.Valid.LinkTo(validSink, new DataflowLinkOptions { PropagateCompletion = false });
node.Invalid.LinkTo(invalidSink, new DataflowLinkOptions { PropagateCompletion = false });

await node.Input.SendAsync(FlowMessage.Create(order));

JsonSchemaValidatorOptions.LoadSchema() compiles the schema once (from inline Schema or SchemaPath), so the node never performs File I/O or compilation in its pump. A missing or malformed schema throws InvalidOperationException at that point — configuration mistakes fail fast.

Value selectors

By default the node validates the whole payload. Pass an IJsonSchemaValueSelector<TInput> to select a value from the payload (e.g. an inner property), plus a valueSelector name carried into the validation result and selector context:

var node = new JsonSchemaValidatorNode<AppMessage>(
    schema,
    selector: new PayloadSelector(),
    valueSelector: "payload");

The node accepts JsonElement, JsonDocument, JsonNode, byte[], string (parsed as JSON when possible, otherwise treated as a string value), and plain objects (serialized) as selected values.

Behavior

Invalid data is not an error: the node emits a result and routes the original input to Invalid. Value-selection, value-conversion, and schema-evaluation failures emit a FlowError on Errors (carrying the input's correlation id and a Code from ValidationErrorCodes) and the node keeps processing later messages. A one-time json.schema-validator.loaded event is emitted on construction, and per-message valid/invalid/failed events flow on the Events port.

Runtime timing

Validation results use the node's clock for Timestamp (default TimeProvider.System). Provide a deterministic clock for tests:

new JsonSchemaValidatorNode<JsonElement>(schema, clock: new FakeTimeProvider(timestamp));