Add methods for retrieving full paginator output and item paths.

smithy-lang · Nov 11, 2020 · 13c7ac2 · 13c7ac2
1 parent 9af70ba
commit 13c7ac2
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Showing 4 changed files with 47 additions and 15 deletions.
diff --git a/smithy-model/src/main/java/software/amazon/smithy/model/knowledge/PaginatedIndex.java b/smithy-model/src/main/java/software/amazon/smithy/model/knowledge/PaginatedIndex.java
@@ -17,6 +17,7 @@
 
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.function.Function;
@@ -81,22 +82,22 @@ private Optional<PaginationInfo> create(
         }
 
         MemberShape inputToken = trait.getInputToken().flatMap(input::getMember).orElse(null);
-        MemberShape outputToken = trait.getOutputToken()
+        List<MemberShape> outputTokenPath = trait.getOutputToken()
                 .flatMap(path -> PaginatedTrait.resolvePath(path, model, output))
                 .orElse(null);
 
-        if (inputToken == null || outputToken == null) {
+        if (inputToken == null || outputTokenPath == null) {
             return Optional.empty();
         }
 
         MemberShape pageSizeMember = trait.getPageSize().flatMap(input::getMember).orElse(null);
-        MemberShape itemsMember = trait.getItems()
+        List<MemberShape> itemsMemberPath = trait.getItems()
                 .flatMap(path -> PaginatedTrait.resolvePath(path, model, output))
                 .orElse(null);
 
         return Optional.of(new PaginationInfo(
                 service, operation, input, output, trait,
-                inputToken, outputToken, pageSizeMember, itemsMember));
+                inputToken, outputTokenPath, pageSizeMember, itemsMemberPath));
     }
 
     public Optional<PaginationInfo> getPaginationInfo(ToShapeId service, ToShapeId operation) {

diff --git a/smithy-model/src/main/java/software/amazon/smithy/model/knowledge/PaginationInfo.java b/smithy-model/src/main/java/software/amazon/smithy/model/knowledge/PaginationInfo.java
@@ -15,6 +15,7 @@
 
 package software.amazon.smithy.model.knowledge;
 
+import java.util.List;
 import java.util.Optional;
 import software.amazon.smithy.model.shapes.MemberShape;
 import software.amazon.smithy.model.shapes.OperationShape;
@@ -33,9 +34,9 @@ public final class PaginationInfo {
     private final StructureShape output;
     private final PaginatedTrait paginatedTrait;
     private final MemberShape inputToken;
-    private final MemberShape outputToken;
+    private final List<MemberShape> outputToken;
     private final MemberShape pageSize;
-    private final MemberShape items;
+    private final List<MemberShape> items;
 
     PaginationInfo(
             ServiceShape service,
@@ -44,9 +45,9 @@ public final class PaginationInfo {
             StructureShape output,
             PaginatedTrait paginatedTrait,
             MemberShape inputToken,
-            MemberShape outputToken,
+            List<MemberShape> outputToken,
             MemberShape pageSize,
-            MemberShape items
+            List<MemberShape> items
     ) {
         this.service = service;
         this.operation = operation;
@@ -88,11 +89,35 @@ public MemberShape getInputTokenMember() {
         return inputToken;
     }
 
+    /**
+     * @return the last {@link MemberShape} of the output path.
+     * @deprecated See getOutputTokenPath.
+     */
     public MemberShape getOutputTokenMember() {
+        int size = outputToken.size();
+        if (size == 0) {
+            return null;
+        }
+        return outputToken.get(size - 1);
+    }
+
+    public List<MemberShape> getOutputTokenPath() {
         return outputToken;
     }
 
+    /**
+     * @return the last {@link MemberShape} of the items path.
+     * @deprecated See getItemsMemberPath
+     */
     public Optional<MemberShape> getItemsMember() {
+        int size = items.size();
+        if (size == 0) {
+            return Optional.empty();
+        }
+        return Optional.ofNullable(items.get(size - 1));
+    }
+
+    public Optional<List<MemberShape>> getItemsMemberPath() {
         return Optional.ofNullable(items);
     }
 

diff --git a/smithy-model/src/main/java/software/amazon/smithy/model/traits/PaginatedTrait.java b/smithy-model/src/main/java/software/amazon/smithy/model/traits/PaginatedTrait.java
@@ -15,6 +15,8 @@
 
 package software.amazon.smithy.model.traits;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Optional;
 import java.util.regex.Pattern;
 import software.amazon.smithy.model.Model;
@@ -90,23 +92,26 @@ public Optional<String> getPageSize() {
      *              of an operation.
      * @return The optional member shape that the path resolves to.
      */
-    public static Optional<MemberShape> resolvePath(
+    public static Optional<List<MemberShape>> resolvePath(
             String path,
             Model model,
             StructureShape shape
     ) {
+        List<MemberShape> memberShapes = new ArrayList<>();
+
         // For each member name in the path, try to find that member in the previous structure
-        Optional<MemberShape> memberShape = Optional.empty();
+        Optional<MemberShape> memberShape;
         Optional<StructureShape> container = Optional.of(shape);
         for (String memberName: PATH_PATTERN.split(path)) {
             memberShape = container.flatMap(structure -> structure.getMember(memberName));
             if (!memberShape.isPresent()) {
                 return Optional.empty();
             }
+            memberShapes.add(memberShape.get());
             container = model.getShape(memberShape.get().getTarget())
                     .flatMap(Shape::asStructureShape);
         }
-        return memberShape;
+        return Optional.of(memberShapes);
     }
 
     /**

diff --git a/...main/java/software/amazon/smithy/model/validation/validators/PaginatedTraitValidator.java b/...main/java/software/amazon/smithy/model/validation/validators/PaginatedTraitValidator.java
@@ -136,9 +136,9 @@ private List<ValidationEvent> validateMember(
 
         if (memberPath == null) {
             return service != null && validator.isRequiredToBePresent()
-                   ? Collections.singletonList(error(operation, trait, String.format(
+                    ? Collections.singletonList(error(operation, trait, String.format(
                     "%spaginated trait `%s` is not configured", prefix, validator.propertyName())))
-                   : Collections.emptyList();
+                    : Collections.emptyList();
         }
 
         if (!validator.pathsAllowed() && memberPath.contains(".")) {
@@ -184,7 +184,7 @@ private List<ValidationEvent> validateMember(
         if (validator.pathsAllowed() && PATH_PATTERN.split(memberPath).length > 2) {
             events.add(warning(operation, trait, String.format(
                     "%spaginated trait `%s` contains a path with more than two parts, which can make your API "
-                        + "cumbersome to use",
+                    + "cumbersome to use",
                     prefix, validator.propertyName()
             )));
         }
@@ -228,7 +228,8 @@ Optional<MemberShape> getMember(
         ) {
             Optional<StructureShape> outputShape = opIndex.getOutput(operation);
             return outputShape.flatMap(structureShape -> getMemberPath(opIndex, operation, trait)
-                    .flatMap(path -> PaginatedTrait.resolvePath(path, model, structureShape)));
+                    .flatMap(path -> PaginatedTrait.resolvePath(path, model, structureShape)))
+                    .map(memberShapes -> memberShapes.get(memberShapes.size() - 1));
         }
     }