Discover tables and validators in runtime using io.github.classgraph #1311
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This effectively reverts commit 7fb105e where registries of tables and validators were generated by the GtfsAnnotationProcessor. It is impossible to reliably generate a registry for multiple classes since there is an orthogonality rule for Java Annotation Processors [1]: “The result of processing a given input is not a function of the presence or absence of other inputs (orthogonality).” In other words, there is no way to guarantee that GtfsAnnotationProcessor receives all schema and validator classes: it may receive only a portion of them, so it cannot generate a global registry. Discovery is implemented in separate classes (ClassGraphTableDiscoverer and ClassGraphValidatorDiscoverer), so that clients of the GTFS Validator may implement their own ways to discover tables and validators. io.github.classgraph is just one option, an alternative is com.google.common.reflect. [1] https://docs.oracle.com/javase/7/docs/api/javax/annotation/processing/Processor.html
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core/src/main/java/org/mobilitydata/gtfsvalidator/table/ClassGraphTableDiscoverer.java
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…obilityData#1311) This effectively reverts commit 7fb105e where registries of tables and validators were generated by the GtfsAnnotationProcessor. It is impossible to reliably generate a registry for multiple classes since there is an orthogonality rule for Java Annotation Processors [1]: “The result of processing a given input is not a function of the presence or absence of other inputs (orthogonality).” In other words, there is no way to guarantee that GtfsAnnotationProcessor receives all schema and validator classes: it may receive only a portion of them, so it cannot generate a global registry. Discovery is implemented in a separate class ClassGraphDiscovery, so that clients of the GTFS Validator may implement their own ways to discover tables and validators. io.github.classgraph is just one option, an alternative is com.google.common.reflect. [1] https://docs.oracle.com/javase/7/docs/api/javax/annotation/processing/Processor.html
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This effectively reverts commit 7fb105e where registries of tables and validators were generated by the GtfsAnnotationProcessor. It is impossible to reliably generate a registry for multiple classes since there is an orthogonality rule for Java Annotation Processors [1]:
“The result of processing a given input is not a function of the presence or absence of other inputs (orthogonality).”
In other words, there is no way to guarantee that GtfsAnnotationProcessor receives all schema and validator classes: it may receive only a portion of them, so it cannot generate a global registry.
[1] https://docs.oracle.com/javase/7/docs/api/javax/annotation/processing/Processor.html