use of io.cdap.cdap.etl.api.Arguments in project hydrator-plugins by cdapio.
the class JavaScriptTransform method init.
private void init(@Nullable TransformContext context, FailureCollector collector) {
ScriptEngineManager manager = new ScriptEngineManager();
engine = manager.getEngineByName("JavaScript");
try {
engine.eval(ScriptConstants.HELPER_DEFINITION);
} catch (ScriptException e) {
// shouldn't happen
collector.addFailure("Failed to define helper functions.", null);
throw collector.getOrThrowException();
}
JavaTypeConverters js = ((Invocable) engine).getInterface(engine.get(ScriptConstants.HELPER_NAME), JavaTypeConverters.class);
LookupConfig lookupConfig;
try {
lookupConfig = GSON.fromJson(config.lookup, LookupConfig.class);
} catch (JsonSyntaxException e) {
collector.addFailure("Invalid lookup config.", "Expected JSON map of string to string.").withConfigProperty(Config.LOOKUP);
throw collector.getOrThrowException();
}
Arguments arguments = context == null ? null : context.getArguments();
engine.put(CONTEXT_NAME, new ScriptContext(LOG, metrics, context, lookupConfig, js, arguments));
try {
// this is pretty ugly, but doing this so that we can pass the 'input' json into the transform function.
// that is, we want people to implement
// function transform(input) { ... }
// rather than function transform() { ... } and have them access a global variable in the function
String script = String.format("function %s() { return transform(%s, %s, %s); }\n%s", FUNCTION_NAME, VARIABLE_NAME, EMITTER_NAME, CONTEXT_NAME, config.script);
engine.eval(script);
} catch (ScriptException e) {
collector.addFailure(String.format("Invalid script: %s.", e.getMessage()), null).withConfigProperty(Config.SCRIPT);
}
invocable = (Invocable) engine;
if (config.schema != null) {
try {
schema = Schema.parseJson(config.schema);
} catch (IOException e) {
collector.addFailure(String.format("Invalid schema: %s.", e.getMessage()), "Output schema must be JSON parseable.").withConfigProperty(Config.SCHEMA);
}
}
collector.getOrThrowException();
}
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