Support customizable filter value serialization in links #403

switched from simple toString to TypeParser that allows to register custom string mappers.
crnk-project · Oct 28, 2018 · d55c8b5 · d55c8b5
1 parent 5585c4f
commit d55c8b5
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Showing 3 changed files with 18 additions and 4 deletions.
diff --git a/crnk-core/src/main/java/io/crnk/core/engine/parser/JacksonStringMapper.java b/crnk-core/src/main/java/io/crnk/core/engine/parser/JacksonStringMapper.java
@@ -3,8 +3,8 @@
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.ObjectReader;
+import com.fasterxml.jackson.databind.node.NumericNode;
 import com.fasterxml.jackson.databind.node.TextNode;
-import com.fasterxml.jackson.databind.node.ValueNode;
 
 import java.io.IOException;
 
@@ -34,9 +34,12 @@ public T parse(String input) {
 	public String toString(T input) {
 		JsonNode jsonNode = mapper.valueToTree(input);
 
-		if (jsonNode instanceof ValueNode) {
+		if (jsonNode instanceof TextNode) {
 			return jsonNode.textValue();
 		}
+		if (jsonNode instanceof NumericNode) {
+			return jsonNode.asText();
+		}
 
 		// fallback to String for complex type
 		return input.toString();

diff --git a/crnk-core/src/main/java/io/crnk/core/queryspec/mapper/DefaultQuerySpecUrlMapper.java b/crnk-core/src/main/java/io/crnk/core/queryspec/mapper/DefaultQuerySpecUrlMapper.java
@@ -2,6 +2,7 @@
 
 import io.crnk.core.engine.information.resource.ResourceInformation;
 import io.crnk.core.engine.internal.utils.ClassUtils;
+import io.crnk.core.engine.internal.utils.PreconditionUtil;
 import io.crnk.core.engine.internal.utils.StringUtils;
 import io.crnk.core.engine.parser.ParserException;
 import io.crnk.core.engine.parser.TypeParser;
@@ -223,11 +224,14 @@ protected String addResourceType(QueryParameterType type, String key, ResourceIn
 		return type.toString().toLowerCase() + "[" + resourceType + "]" + (key != null ? key : "");
 	}
 
-	protected static String serializeValue(Object value) {
+	protected String serializeValue(Object value) {
 		if (value == null) {
 			return NULL_VALUE_STRING;
 		}
-		return value.toString();
+		TypeParser typeParser = context.getTypeParser();
+		String strValue = typeParser.toString(value);
+		PreconditionUtil.verify(strValue != null, "should not map to null: %s", value);
+		return strValue;
 	}
 
 	@Override

diff --git a/crnk-documentation/src/docs/releases/latest/info.html b/crnk-documentation/src/docs/releases/latest/info.html
@@ -176,6 +176,13 @@ <h4>Historic Activiti repositories</h4>
 return ActivitiModule.create(processEngine, config);
 </pre>
 
+<h4>Bidirectional Object to String mapping with TypeParser</h4>
+
+The TypeParser class of Crnk has been extended to not only parse Strings, but also map objects back to Strings.
+Most notably, the DefaultQuerySpecUrlMapper makes use of this functionality to represent filter values
+as Strings in urls. Thereby, the extensibility of the TypeParser allows to customize that mapping.
+
+
 
 <h4>Simplified customizations of Criteria-based crnk-jpa repositories</h4>