[GitHub] nifi pull request #1157: NIFI-2791 Adding 'math' expression language functio...

[asfgit]

Github user asfgit closed the pull request at:

https://github.com/apache/nifi/pull/1157


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[GitHub] nifi pull request #1157: NIFI-2791 Adding 'math' expression language functio...

[pvillard31]

Github user pvillard31 commented on a diff in the pull request:

https://github.com/apache/nifi/pull/1157#discussion_r84855173
  
--- Diff: 
nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/evaluation/functions/MathEvaluator.java
 ---
@@ -0,0 +1,138 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.attribute.expression.language.evaluation.functions;
+
+import org.apache.nifi.attribute.expression.language.evaluation.Evaluator;
+import 
org.apache.nifi.attribute.expression.language.evaluation.NumberEvaluator;
+import 
org.apache.nifi.attribute.expression.language.evaluation.NumberQueryResult;
+import 
org.apache.nifi.attribute.expression.language.evaluation.QueryResult;
+import 
org.apache.nifi.attribute.expression.language.exception.AttributeExpressionLanguageException;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Map;
+
+public class MathEvaluator extends NumberEvaluator {
+
+private final Evaluator subject;
+private final Evaluator methodName;
+private final Evaluator optionalArg;
+
+public MathEvaluator(final Evaluator subject, final 
Evaluator methodName, final Evaluator optionalArg) {
+this.subject = subject;
+this.methodName = methodName;
+this.optionalArg = optionalArg;
+}
+
+@Override
+public QueryResult evaluate(final Map 
attributes) {
+final String methodNamedValue = 
methodName.evaluate(attributes).getValue();
+if (methodNamedValue == null) {
+return new NumberQueryResult(null);
+}
+
+final Number subjectValue;
+if(subject != null) {
+subjectValue = subject.evaluate(attributes).getValue();
+if(subjectValue == null){
+return new NumberQueryResult(null);
+}
+} else {
+subjectValue = null;
+}
+
+final Number optionalArgValue;
+if(optionalArg != null) {
+optionalArgValue = optionalArg.evaluate(attributes).getValue();
+
+if(optionalArgValue == null) {
+return new NumberQueryResult(null);
+}
+} else {
+optionalArgValue = null;
+}
+
+try {
+Number executionValue = null;
+
+if (subjectValue == null){
+Method method = Math.class.getMethod(methodNamedValue);
+
+if(method == null) {
+throw new AttributeExpressionLanguageException("Cannot 
evaluate 'math' function because no subjectless method was found with the 
name:'" + methodNamedValue + "'");
+}
+
+executionValue = (Number) method.invoke(null);
+} else if(optionalArg == null) {
+boolean subjectIsDecimal = subjectValue instanceof Double;
+Method method = Math.class.getMethod(methodNamedValue, 
subjectIsDecimal ? double.class : long.class);
--- End diff --

If I use:

${filename:math('exp')}

I'll get the following exception:


org.apache.nifi.attribute.expression.language.exception.AttributeExpressionLanguageException:
 Unable to calculate math function value
at 
org.apache.nifi.attribute.expression.language.evaluation.functions.MathEvaluator.evaluate(MathEvaluator.java:129)
 ~[nifi-expression-language-1.1.0-SNAPSHOT.jar:1.1.0-SNAPSHOT]
at 
org.apache.nifi.attribute.expression.language.Query.evaluate(Query.java:568) 
~[nifi-expression-language-1.1.0-SNAPSHOT.jar:1.1.0-SNAPSHOT]
at 
org.apache.nifi.attribute.expression.language.Query.evaluateExpression(Query.java:386)
 ~[nifi-expression-language-1.1.0-SNAPSHOT.jar:1.1.0-SNAPSHOT]
at 

[GitHub] nifi pull request #1157: NIFI-2791 Adding 'math' expression language functio...

[JPercivall]

GitHub user JPercivall opened a pull request:

https://github.com/apache/nifi/pull/1157

NIFI-2791 Adding 'math' expression language function

Thank you for submitting a contribution to Apache NiFi.

In order to streamline the review of the contribution we ask you
to ensure the following steps have been taken:

### For all changes:
- [x] Is there a JIRA ticket associated with this PR? Is it referenced 
 in the commit message?

- [x] Does your PR title start with NIFI- where  is the JIRA number 
you are trying to resolve? Pay particular attention to the hyphen "-" character.

- [x] Has your PR been rebased against the latest commit within the target 
branch (typically master)?

- [x] Is your initial contribution a single, squashed commit?

### For code changes:
- [x] Have you ensured that the full suite of tests is executed via mvn 
-Pcontrib-check clean install at the root nifi folder?
- [x] Have you written or updated unit tests to verify your changes?
- [x] If adding new dependencies to the code, are these dependencies 
licensed in a way that is compatible for inclusion under [ASF 
2.0](http://www.apache.org/legal/resolved.html#category-a)? 
- [x] If applicable, have you updated the LICENSE file, including the main 
LICENSE file under nifi-assembly?
- [x] If applicable, have you updated the NOTICE file, including the main 
NOTICE file found under nifi-assembly?
- [x] If adding new Properties, have you added .displayName in addition to 
.name (programmatic access) for each of the new properties?

### For documentation related changes:
- [x] Have you ensured that format looks appropriate for the output in 
which it is rendered?

### Note:
Please ensure that once the PR is submitted, you check travis-ci for build 
issues and submit an update to your PR as soon as possible.



You can merge this pull request into a Git repository by running:

$ git pull https://github.com/JPercivall/nifi NIFI-2791

Alternatively you can review and apply these changes as the patch at:

https://github.com/apache/nifi/pull/1157.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

This closes #1157


commit 2c5a4fc193831464862a1a051c3a6b79dc651a9c
Author: jpercivall 
Date:   2016-10-20T14:58:53Z

NIFI-2791 Adding 'math' expression language function




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