Refactoring examples + docs

Author: leandrodamascena

docs/core/event_handler/appsync.md

@@ -290,7 +290,7 @@ You can use `append_context` when you want to share data between your App and Ro
 
 ### Batch processing
 
-We support Appsync's batching mechanism for Lambda Resolvers. To handle multiple events in a batch and prevent multiple lambda executions, configure your Appsync to group events and use the `@batch_resolver` or `@async_batch_resolver` decorators.
+We support AWS Appsync's batching mechanism for Lambda Resolvers. It prevents multiple Lambda executions by grouping events and using the `@batch_resolver` or `@async_batch_resolver` decorators to resolve the entire batch.
 
 ???+ info
     If you want to understand more how to configure batch processing for the AppSync, please follow this [guide](https://aws.amazon.com/blogs/mobile/introducing-configurable-batching-size-for-aws-appsync-lambda-resolvers/){target="_blank"}.
@@ -300,28 +300,38 @@ We support Appsync's batching mechanism for Lambda Resolvers. To handle multiple
     --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_resolver.py"
   	```
 
+    1. The entire batch is sent to the resolver, and you need to iterate through it to process all records.
+
 === "getting_started_with_batch_resolver_payload.json"
   	```json hl_lines="4 16 21 29 41 46"
     --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_resolver_payload.json"
   	```
 
-#### Handling exceptions
+#### Processing Batch items individually
 
-By default, records that fail during Lambda execution return `None` to ensure the entire batch doesn't fail due to processing errors. However, you have the option to actively return exceptions for debugging or troubleshooting.
+You can process each item in the batch individually, and we can handle exceptions for you. However, it's important to note that utilizing this method may increase the execution time of your Lambda function.
 
 ???+ tip
     For better error handling, you may need to configure response mapping templates and specify error keys. Explore more on returning individual errors [here](https://docs.aws.amazon.com/appsync/latest/devguide/tutorial-lambda-resolvers.html#advanced-use-case-batching){target="_blank"}.
 
-=== "enable_exceptions_batch_resolver.py"
-  	```python hl_lines="3 7 21"
-    --8<-- "examples/event_handler_graphql/src/enable_exceptions_batch_resolver.py"
+=== "getting_started_with_batch_resolver_individual.py"
+  	```python hl_lines="3 7 17"
+    --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_resolver_individual.py"
+  	```
+
+    1. You need to disable the aggregated event by using `aggregate` flag.
+        The resolver receives and processes each record one at a time.
+
+=== "getting_started_with_batch_resolver_handling_error.py"
+  	```python hl_lines="3 7 17"
+    --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_resolver_handling_error.py"
   	```
 
-    1. You can enable the exceptions by setting `raise_on_error` to True.
+    1. You can enable enable the error handling by using `raise_on_error` flag.
 
-=== "enable_exceptions_batch_resolver_payload.json"
+=== "getting_started_with_batch_resolver_payload.json"
   	```json hl_lines="4 16 21 29 41 46"
-    --8<-- "examples/event_handler_graphql/src/enable_exceptions_batch_resolver_payload.json"
+    --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_resolver_payload.json"
   	```
 
 #### Async

examples/event_handler_graphql/src/getting_started_with_batch_async_resolver.py

@@ -1,9 +1,11 @@
-from typing import Dict, Optional
+from typing import Any, List, Optional
 
+from aws_lambda_powertools import Logger
 from aws_lambda_powertools.event_handler import AppSyncResolver
 from aws_lambda_powertools.utilities.data_classes import AppSyncResolverEvent
 from aws_lambda_powertools.utilities.typing import LambdaContext
 
+logger = Logger()
 app = AppSyncResolver()
 
 
@@ -15,8 +17,18 @@
 
 
 @app.async_batch_resolver(type_name="Query", field_name="relatedPosts")
-async def related_posts(event: AppSyncResolverEvent, post_id: str) -> Optional[Dict]:
-    return posts_related.get(post_id, None)
+async def related_posts(event: List[AppSyncResolverEvent]) -> Optional[List[Any]]:
+    results = []
+
+    for record in event:  # (1)!
+        post_id = record.arguments.get("post_id")
+        try:
+            results.append(posts_related[post_id] if post_id else None)
+            # Add other logic here
+        except Exception:
+            logger.error("Error processing record", post_id=post_id)
+
+    return results
 
 
 def lambda_handler(event, context: LambdaContext) -> dict:

examples/event_handler_graphql/src/getting_started_with_batch_resolver.py

@@ -1,9 +1,11 @@
-from typing import Dict, Optional
+from typing import Any, List
 
+from aws_lambda_powertools import Logger
 from aws_lambda_powertools.event_handler import AppSyncResolver
 from aws_lambda_powertools.utilities.data_classes import AppSyncResolverEvent
 from aws_lambda_powertools.utilities.typing import LambdaContext
 
+logger = Logger()
 app = AppSyncResolver()
 
 
@@ -15,8 +17,18 @@
 
 
 @app.batch_resolver(type_name="Query", field_name="relatedPosts")
-def related_posts(event: AppSyncResolverEvent, post_id: str) -> Optional[Dict]:
-    return posts_related.get(post_id, None)
+def related_posts(event: List[AppSyncResolverEvent]) -> List[Any]:
+    results = []
+
+    for record in event:  # (1)!
+        post_id = record.arguments.get("post_id")
+        try:
+            results.append(posts_related[post_id] if post_id else None)
+            # Add other logic here
+        except Exception:
+            logger.error("Error processing record", post_id=post_id)
+
+    return results
 
 
 def lambda_handler(event, context: LambdaContext) -> dict:

examples/event_handler_graphql/src/getting_started_with_batch_resolver_handling_error.py

@@ -0,0 +1,25 @@
+from typing import Any, Dict
+
+from aws_lambda_powertools import Logger
+from aws_lambda_powertools.event_handler import AppSyncResolver
+from aws_lambda_powertools.utilities.data_classes import AppSyncResolverEvent
+from aws_lambda_powertools.utilities.typing import LambdaContext
+
+logger = Logger()
+app = AppSyncResolver()
+
+
+posts_related = {
+    "1": {"title": "post1"},
+    "2": {"title": "post2"},
+    "3": {"title": "post3"},
+}
+
+
+@app.batch_resolver(type_name="Query", field_name="relatedPosts", aggregate=False, raise_on_error=True)  # (1)!
+def related_posts(event: AppSyncResolverEvent, post_id: str = "") -> Dict[str, Any]:
+    return posts_related[post_id]
+
+
+def lambda_handler(event, context: LambdaContext) -> dict:
+    return app.resolve(event, context)

examples/event_handler_graphql/src/getting_started_with_batch_resolver_individual.py

@@ -0,0 +1,25 @@
+from typing import Any, Dict
+
+from aws_lambda_powertools import Logger
+from aws_lambda_powertools.event_handler import AppSyncResolver
+from aws_lambda_powertools.utilities.data_classes import AppSyncResolverEvent
+from aws_lambda_powertools.utilities.typing import LambdaContext
+
+logger = Logger()
+app = AppSyncResolver()
+
+
+posts_related = {
+    "1": {"title": "post1"},
+    "2": {"title": "post2"},
+    "3": {"title": "post3"},
+}
+
+
+@app.batch_resolver(type_name="Query", field_name="relatedPosts", aggregate=False)  # (1)!
+def related_posts(event: AppSyncResolverEvent, post_id: str = "") -> Dict[str, Any]:
+    return posts_related[post_id]
+
+
+def lambda_handler(event, context: LambdaContext) -> dict:
+    return app.resolve(event, context)

examples/event_handler_graphql/src/getting_started_with_batch_resolver_payload.json

@@ -26,7 +26,7 @@
     },
     {
         "arguments":{
-           "post_id":"10"
+           "post_id":"2"
         },
         "identity":"None",
         "source":"None",