Github user mattyb149 commented on a diff in the pull request:
https://github.com/apache/nifi/pull/2749#discussion_r192408467
--- Diff:
nifi-nar-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/ListFileTransfer.java
---
@@ -43,7 +43,7 @@
.description("The fully qualified hostname or IP address of the
remote system")
.addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
.required(true)
-
.expressionLanguageSupported(ExpressionLanguageScope.VARIABLE_REGISTRY)
+
.expressionLanguageSupported(ExpressionLanguageScope.FLOWFILE_ATTRIBUTES)
--- End diff --
According to
[this](https://github.com/apache/nifi/pull/2749/files#diff-a68a345757d54ad30f79658062d6e794R76),
the attributes will not be populated with the right information if the
attributes come in from flow files as no FlowFile is passed in.
This is a weird thing because ListFTP declares a property HOSTNAME that had
EL scope VARIABLE_REGISTRY. But it also creates an FTPTransfer object which
declares a HOSTNAME property that has EL scope FLOWFILES. Because they have the
same name, the context fetches the FTPTransfer property but gets ListFTP's
property instead. Then it calls evaluateAttributeExpressions(flowFile), but
that violates ListFTP's HOSTNAME EL scope.
This fix prevents the violation, but the attributes would still be
incorrect right? I mention that because I thought of applying this same fix but
instead put in the one from #2717
---
