Merge pull request #20 from sidhant92/develop

Default Field Support

Author: sidhant92

build.gradle

@@ -22,7 +22,7 @@ sourceCompatibility = 1.8
 targetCompatibility = 1.8
 
 group 'com.github.sidhant92'
-version = "1.0.1"
+version = "1.1.0"
 
 apply plugin: "com.dipien.semantic-version"
 

src/main/java/com/github/sidhant92/boolparser/application/BooleanExpressionEvaluator.java

@@ -34,11 +34,15 @@ public BooleanExpressionEvaluator(final BoolExpressionParser boolExpressionParse
         operatorService = new OperatorService();
     }
 
-    public Try<Boolean> evaluate(final String expression, final Map<String, Object> data) {
-        final Try<Node> tokenOptional = boolExpressionParser.parseExpression(expression);
+    public Try<Boolean> evaluate(final String expression, final Map<String, Object> data, final String defaultField) {
+        final Try<Node> tokenOptional = boolExpressionParser.parseExpression(expression, defaultField);
         return tokenOptional.map(node -> evaluateToken(node, data));
     }
 
+    public Try<Boolean> evaluate(final String expression, final Map<String, Object> data) {
+        return evaluate(expression, data, null);
+    }
+
     private boolean evaluateToken(final Node node, final Map<String, Object> data) {
         switch (node.getTokenType()) {
             case COMPARISON:

src/main/java/com/github/sidhant92/boolparser/parser/BoolExpressionParser.java

@@ -9,4 +9,6 @@
  */
 public interface BoolExpressionParser {
     Try<Node> parseExpression(final String expression);
+
+    Try<Node> parseExpression(final String expression, final String defaultField);
 }

src/main/java/com/github/sidhant92/boolparser/parser/antlr/BoolParser.java

@@ -28,25 +28,30 @@ public BoolParser(final int maxCacheSize) {
         this.cache = Caffeine.newBuilder().maximumSize(maxCacheSize).build();
     }
 
+    @Override
+    public Try<Node> parseExpression(final String expression, final String defaultField) {
+        return Try.of(() -> getNode(expression, defaultField));
+    }
+
     @Override
     public Try<Node> parseExpression(final String expression) {
-        return Try.of(() -> getNode(expression));
+        return Try.of(() -> getNode(expression, null));
     }
 
-    private Node getNode(final String expression) {
+    private Node getNode(final String expression, final String defaultField) {
         if (useCache) {
-            return cache.get(expression, this::parse);
+            return cache.get(expression, ex -> parse(ex, defaultField));
         }
-        return parse(expression);
+        return parse(expression, defaultField);
     }
 
-    private Node parse(final String expression) {
+    private Node parse(final String expression, final String defaultField) {
         final BooleanExpressionLexer filterLexer = new BooleanExpressionLexer(CharStreams.fromString(expression));
         final CommonTokenStream commonTokenStream = new CommonTokenStream(filterLexer);
         final BooleanExpressionParser filterParser = new BooleanExpressionParser(commonTokenStream);
         final ParseTree parseTree = filterParser.parse();
 
-        final BooleanFilterListener listener = new BooleanFilterListener();
+        final BooleanFilterListener listener = new BooleanFilterListener(defaultField);
         parseTreeWalker.walk(listener, parseTree);
 
         return listener.getNode();

src/main/java/com/github/sidhant92/boolparser/parser/antlr/BooleanFilterListener.java

@@ -1,8 +1,10 @@
 package com.github.sidhant92.boolparser.parser.antlr;
 
 import java.util.List;
+import java.util.Objects;
 import java.util.Stack;
 import java.util.stream.Collectors;
+import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.tuple.Pair;
 import com.github.sidhant92.boolparser.constant.DataType;
 import com.github.sidhant92.boolparser.constant.LogicalOperationType;
@@ -25,7 +27,10 @@ public class BooleanFilterListener extends BooleanExpressionBaseListener {
 
     private org.antlr.v4.runtime.Token lastToken;
 
-    public BooleanFilterListener() {
+    private String defaultField;
+
+    public BooleanFilterListener(final String defaultField) {
+        this.defaultField = defaultField;
         this.node = null;
         this.lastToken = null;
         this.currentNodes = new Stack<>();
@@ -37,7 +42,7 @@ public Node getNode() {
 
     @Override
     public void exitComparatorExpression(BooleanExpressionParser.ComparatorExpressionContext ctx) {
-        final String variableName = ctx.left.getText();
+        final String variableName = getField(ctx.left.getText());
         final DataType dataType = getDataType(ctx.right.getStart());
         final Operator operator = Operator.getOperatorFromSymbol(ctx.op.getText()).orElse(Operator.EQUALS);
         currentNodes.add(new ComparisonNode(variableName, ValueUtils.convertValue(ctx.right.getText(), dataType), operator, dataType));
@@ -46,7 +51,7 @@ public void exitComparatorExpression(BooleanExpressionParser.ComparatorExpressio
 
     @Override
     public void exitToExpression(BooleanExpressionParser.ToExpressionContext ctx) {
-        final String field = ctx.field.getText();
+        final String field = getField(ctx.field.getText());
         final DataType lowerDataType = getDataType(ctx.lower.start);
         final Object lowerValue = ValueUtils.convertValue(ctx.lower.start.getText(), lowerDataType);
         final DataType upperDataType = getDataType(ctx.upper.start);
@@ -57,7 +62,7 @@ public void exitToExpression(BooleanExpressionParser.ToExpressionContext ctx) {
 
     @Override
     public void exitInExpression(BooleanExpressionParser.InExpressionContext ctx) {
-        final String field = ctx.field.getText();
+        final String field = getField(ctx.field.getText());
         final List<Pair<DataType, Object>> items = ctx.data.children
                 .stream()
                 .filter(child -> child instanceof BooleanExpressionParser.TypesContext)
@@ -71,6 +76,13 @@ public void exitInExpression(BooleanExpressionParser.InExpressionContext ctx) {
         super.exitInExpression(ctx);
     }
 
+    private String getField(final String field) {
+        if (Objects.isNull(defaultField)) {
+            return field;
+        }
+        return StringUtils.isBlank(field) ? defaultField : field;
+    }
+
     private DataType getDataType(final org.antlr.v4.runtime.Token token) {
         switch (token.getType()) {
             case BooleanExpressionLexer.DECIMAL:

src/test/java/com/github/sidhant92/boolparser/application/BooleanExpressionEvaluatorTest.java

@@ -419,4 +419,22 @@ public void testStringEqualityWithQuotes() {
         assertTrue(booleanOptional.isSuccess());
         assertTrue(booleanOptional.get());
     }
+
+    @Test
+    public void testDefaultFieldTrue() {
+        final Map<String, Object> data = new HashMap<>();
+        data.put("age", 19);
+        final Try<Boolean> booleanOptional = booleanExpressionEvaluator.evaluate(">= 18 AND < 20", data, "age");
+        assertTrue(booleanOptional.isSuccess());
+        assertTrue(booleanOptional.get());
+    }
+
+    @Test
+    public void testDefaultFieldFalse() {
+        final Map<String, Object> data = new HashMap<>();
+        data.put("age", 17);
+        final Try<Boolean> booleanOptional = booleanExpressionEvaluator.evaluate(">= 18 AND < 20", data, "age");
+        assertTrue(booleanOptional.isSuccess());
+        assertFalse(booleanOptional.get());
+    }
 }