NIFI-6670: Add TextLineReader to read lines of text as single-field records #3735

mattyb149 · 2019-09-13T18:28:29Z

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MikeThomsen

Still working through it, but have some questions/ideas for you consideration.

MikeThomsen · 2019-10-07T15:28:00Z

...le/nifi-record-serialization-services/src/main/java/org/apache/nifi/text/TextLineReader.java

+
+    @Override
+    protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+        final List<PropertyDescriptor> properties = new ArrayList<>(super.getSupportedPropertyDescriptors());


It would be a bit more efficient to create this all at once with a static constructor such as

public static final List<PropertyDescriptor> PROPS = Collections.unmodifiableList(Arrays.asList(.....));

@mattyb149 can you address this? or reply?

This is done differently by different processors, I copied this part of the code from some other RecordReader.

MikeThomsen · 2019-10-07T15:30:22Z

...i-record-serialization-services/src/main/java/org/apache/nifi/text/TextLineRecordReader.java

+        this.linesLeftToSkip = skipLineCount;
+        this.linesPerGroup = linesPerGroup;
+        this.ignoreEmptyLines = ignoreEmptyLines;
+        final List<RecordField> fieldList = Collections.singletonList(new RecordField(fieldName, RecordFieldType.STRING.getDataType()));


As a default, that's a good one, but there should be some connection to a schema registry so users can do things like specify numeric inputs.

The benefit here is that you don't need to provide a schema. Otherwise I would think a GrokReader would suffice?

ottobackwards · 2019-10-07T15:36:56Z

This seems like the kind of thing that would be, or could be used as the base class for other "line by line readers". If this existed before grok reader for example, wouldn't thought go to extending this to implement that?

How easy do you think it would be to inherit from this reader?

…ecords

…d w unit test

mattyb149 · 2020-08-12T21:21:20Z

This one isn't currently designed to be subclassed (none of the actual component implementations are), but if there is some reusable code (a base class for example) we could consider putting it in the API.

@ottobackwards @MikeThomsen I've updated the PR, rebased against main, and added the additional feature of allowing the entire content to be treated as a record (by setting Lines Per Record to zero), any chance you could review again? Thanks in advance!

ottobackwards · 2020-08-12T22:09:26Z

...i-record-serialization-services/src/main/java/org/apache/nifi/text/TextLineRecordReader.java

+        final List<RecordField> fieldList = Collections.singletonList(new RecordField(fieldName, RecordFieldType.STRING.getDataType()));
+        schema = new SimpleRecordSchema(fieldList);
+    }
+


I know there is no requirement for java doc, but this function is pretty important, and the most likely place for maintainability.

Could you add an overview/summary of the goals, approach, logic and concerns?
It will keep folks like me from messing it up

ottobackwards · 2020-08-12T22:14:55Z

...le/nifi-record-serialization-services/src/main/java/org/apache/nifi/text/TextLineReader.java

+
+    protected static final PropertyDescriptor IGNORE_EMPTY_LINES = new PropertyDescriptor.Builder()
+            .name("linereader-ignore-empty-lines")
+            .displayName("Ignore Empty Lines")


I'm not sure I understand this. Can you reword and clarify how this relates to other properties?

ottobackwards · 2020-08-12T22:18:15Z

...on-services-bundle/nifi-record-serialization-services/src/test/resources/text/test_lines.txt

@@ -0,0 +1,7 @@
+Header line 1


Would it make sense to test multiple sequential empty lines instead of just a single?

mattyb149 · 2021-03-25T19:27:33Z

Closing my PR for now due to inactivity and the fact that you can use a GrokReader with Schema Access Strategy set to "Use String Fields from Grok Expression" (the default) and a Grok Expression of

%{GREEDYDATA:message}

MikeThomsen reviewed Oct 7, 2019

View reviewed changes

mattyb149 changed the base branch from master to main August 12, 2020 20:15

mattyb149 added 2 commits August 12, 2020 16:17

NIFI-6670: Add TextLineReader to read lines of text as single-field r…

effc71a

…ecords

NIFI-6670: Rebased @ main, support all content as one record, verifie…

ae28e45

…d w unit test

mattyb149 force-pushed the NIFI-6670 branch from 9d5aa5e to ae28e45 Compare August 12, 2020 20:39

ottobackwards reviewed Aug 12, 2020

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mattyb149 closed this Mar 25, 2021

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NIFI-6670: Add TextLineReader to read lines of text as single-field records #3735

NIFI-6670: Add TextLineReader to read lines of text as single-field records #3735

mattyb149 commented Sep 13, 2019

MikeThomsen left a comment

MikeThomsen Oct 7, 2019

ottobackwards Aug 12, 2020

mattyb149 Aug 13, 2020

MikeThomsen Oct 7, 2019

mattyb149 Jan 22, 2020

ottobackwards commented Oct 7, 2019

mattyb149 commented Aug 12, 2020

ottobackwards Aug 12, 2020 •

edited

ottobackwards Aug 12, 2020

ottobackwards Aug 12, 2020

mattyb149 commented Mar 25, 2021

NIFI-6670: Add TextLineReader to read lines of text as single-field records #3735

NIFI-6670: Add TextLineReader to read lines of text as single-field records #3735

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mattyb149 commented Sep 13, 2019

Description of PR

For all changes:

For code changes:

For documentation related changes:

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ottobackwards commented Oct 7, 2019

mattyb149 commented Aug 12, 2020

ottobackwards Aug 12, 2020 • edited

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mattyb149 commented Mar 25, 2021

ottobackwards Aug 12, 2020 •

edited