OnPropertyCondition class

A Condition implementation that evaluates whether a component or pod should be activated based on the presence and value of properties in the current ConditionalContext.environment.

OnPropertyCondition is typically used in conjunction with the ConditionalOnProperty annotation, which specifies property names, optional prefixes, expected values, and whether missing properties should still allow activation.

Behavior

• If the annotated element does not have a ConditionalOnProperty annotation, this condition automatically passes.
• Retrieves the annotation from the source using Annotation.getDirectAnnotation.
• For each property name:
  • Combines the optional prefix with the property name to form the full key.
  • Retrieves the property's value from environment.getProperty.
  • If the property is missing:
    • Passes if matchIfMissing is true.
    • Fails if matchIfMissing is false.
  • If havingValue is specified, the property's value must match (case-insensitive) to pass.
  • If havingValue is not specified, any value equal to "false" causes the condition to fail.
• Logs trace information at every evaluation step if logging is enabled.

Example

@ConditionalOnProperty(
  prefix: 'server',
  names: ['ssl.enabled', 'ssl.enabled2'],
  havingValue: 'true',
  matchIfMissing: false,
)
class SslServerConfig {}

// During context evaluation:
final context = ConditionalContext(environment, podFactory, runtimeProvider);
final condition = OnPropertyCondition();
final shouldActivate = await condition.matches(context, source);

Logging

Trace logging provides detailed step-by-step information:

• Annotation presence and retrieval.
• Property key resolution and value checks.
• Pass/fail decisions for each property.

Related Components

• ConditionalContext: Provides access to environment properties and other conditional evaluation data.
• ConditionalOnProperty: Annotation that defines the properties to evaluate for conditional activation.
• Annotation: The metadata source of the annotated element.