feat(cdk): Add RecordExpander component for nested array extraction

airbyte_cdk/sources/declarative/declarative_component_schema.yaml

@@ -1927,6 +1927,10 @@ definitions:
           - ["data", "records"]
           - ["data", "{{ parameters.name }}"]
           - ["data", "*", "record"]
+      record_expander:
+        title: Record Expander
+        description: Optional component to expand records by extracting items from nested array fields.
+        "$ref": "#/definitions/RecordExpander"
       $parameters:
         type: object
         additionalProperties: true
@@ -1943,6 +1947,86 @@ definitions:
       $parameters:
         type: object
         additionalProperties: true
+  RecordExpander:
+    title: Record Expander
+    description: Expands records by extracting items from a nested array field. When configured, this component extracts items from a specified nested array path within each record and emits each item as a separate record. Optionally, the original parent record can be embedded in each expanded item for context preservation. Supports wildcards (*) for matching multiple arrays.
+    type: object
+    required:
+      - type
+      - expand_records_from_field
+    properties:
+      type:
+        type: string
+        enum: [RecordExpander]
+      expand_records_from_field:
+        title: Expand Records From Field
+        description: Path to a nested array field within each record. Items from this array will be extracted and emitted as separate records. Supports wildcards (*) for matching multiple arrays.
+        type: array
+        items:
+          type: string
+        interpolation_context:
+          - config
+        examples:
+          - ["lines", "data"]
+          - ["items"]
+          - ["nested", "array"]
+          - ["sections", "*", "items"]
+      remain_original_record:
+        title: Remain Original Record
+        description: If true, each expanded record will include the original parent record in an "original_record" field. Defaults to false.
+        type: boolean
+        default: false
+      on_no_records:
+        title: On No Records
+        description: Behavior when the expansion path is missing, not a list, or an empty list. "skip" (default) emits nothing. "emit_parent" emits the original parent record unchanged.
+        type: string
+        enum:
+          - skip
+          - emit_parent
+        default: skip
+      parent_fields_to_copy:
+        title: Parent Fields To Copy
+        description: List of parent field mappings to copy onto each expanded child record. Each mapping specifies a source path in the parent record and a target field name in the child record.
+        type: array
+        items:
+          "$ref": "#/definitions/ParentFieldMapping"
+      $parameters:
+        type: object
+        additionalProperties: true
+  ParentFieldMapping:
+    title: Parent Field Mapping
+    description: Defines a mapping from a parent record field to a child record field.
+    type: object
+    required:
+      - type
+      - source_field_path
+      - target_field
+    properties:
+      type:
+        type: string
+        enum: [ParentFieldMapping]
+      source_field_path:
+        title: Source Field Path
+        description: Path to the field in the parent record to copy.
+        type: array
+        items:
+          type: string
+        interpolation_context:
+          - config
+        examples:
+          - ["id"]
+          - ["created"]
+          - ["metadata", "timestamp"]
+      target_field:
+        title: Target Field
+        description: Name of the field in the child record where the value will be copied.
+        type: string
+        examples:
+          - "parent_id"
+          - "subscription_updated"
+      $parameters:
+        type: object
+        additionalProperties: true
   ExponentialBackoffStrategy:
     title: Exponential Backoff
     description: Backoff strategy with an exponential backoff interval. The interval is defined as factor * 2^attempt_count.

airbyte_cdk/sources/declarative/expanders/__init__.py

@@ -0,0 +1,10 @@
+#
+# Copyright (c) 2023 Airbyte, Inc., all rights reserved.
+#
+
+from airbyte_cdk.sources.declarative.expanders.record_expander import (
+    ParentFieldMapping,
+    RecordExpander,
+)
+
+__all__ = ["ParentFieldMapping", "RecordExpander"]

airbyte_cdk/sources/declarative/expanders/record_expander.py

@@ -0,0 +1,153 @@
+#
+# Copyright (c) 2023 Airbyte, Inc., all rights reserved.
+#
+
+from dataclasses import InitVar, dataclass, field
+from typing import Any, Iterable, Mapping, MutableMapping
+
+import dpath
+
+from airbyte_cdk.sources.declarative.interpolation.interpolated_string import InterpolatedString
+from airbyte_cdk.sources.types import Config
+
+
+@dataclass
+class ParentFieldMapping:
+    """Defines a mapping from a parent record field to a child record field."""
+
+    source_field_path: list[str | InterpolatedString]
+    target_field: str
+    config: Config
+    parameters: InitVar[Mapping[str, Any]]
+
+    def __post_init__(self, parameters: Mapping[str, Any]) -> None:
+        self._source_path = [
+            InterpolatedString.create(path, parameters=parameters)
+            for path in self.source_field_path
+        ]
+
+    def copy_field(
+        self, parent_record: Mapping[str, Any], child_record: MutableMapping[str, Any]
+    ) -> None:
+        """Copy a field from parent record to child record."""
+        source_path = [path.eval(self.config) for path in self._source_path]
+        try:
+            value = dpath.get(dict(parent_record), source_path)
+            child_record[self.target_field] = value
+        except KeyError:
+            pass  # Missing source fields in parent record are expected and intentionally skipped
+
+
+@dataclass
+class RecordExpander:
+    """Expands records by extracting items from a nested array field.
+
+    When configured, this component extracts items from a specified nested array path
+    within each record and emits each item as a separate record. Optionally, the original
+    parent record can be embedded in each expanded item for context preservation.
+
+    The expand_records_from_field path supports wildcards (*) for matching multiple arrays.
+    When wildcards are used, items from all matched arrays are extracted and emitted.
+
+    Examples of instantiating this component:
+    ```
+      record_expander:
+        type: RecordExpander
+        expand_records_from_field:
+          - "lines"
+          - "data"
+        remain_original_record: true
+    ```
+
+    ```
+      record_expander:
+        type: RecordExpander
+        expand_records_from_field:
+          - "sections"
+          - "*"
+          - "items"
+        on_no_records: emit_parent
+        parent_fields_to_copy:
+          - type: ParentFieldMapping
+            source_field_path: ["id"]
+            target_field: "parent_id"
+    ```
+
+    Attributes:
+        expand_records_from_field: Path to a nested array field within each record.
+            Items from this array will be extracted and emitted as separate records.
+            Supports wildcards (*).
+        remain_original_record: If True, each expanded record will include the original
+            parent record in an "original_record" field. Defaults to False.
+        on_no_records: Behavior when expansion produces no records. "skip" (default)
+            emits nothing. "emit_parent" emits the original parent record unchanged.
+        parent_fields_to_copy: List of field mappings to copy from parent to each
+            expanded child record.
+        config: The user-provided configuration as specified by the source's spec.
+    """
+
+    expand_records_from_field: list[str | InterpolatedString]
+    config: Config
+    parameters: InitVar[Mapping[str, Any]]
+    remain_original_record: bool = False
+    on_no_records: str = "skip"
+    parent_fields_to_copy: list[ParentFieldMapping] = field(default_factory=list)
+
+    def __post_init__(self, parameters: Mapping[str, Any]) -> None:
+        self._expand_path: list[InterpolatedString] | None = [
+            InterpolatedString.create(path, parameters=parameters)
+            for path in self.expand_records_from_field
+        ]
+
+    def expand_record(self, record: MutableMapping[Any, Any]) -> Iterable[MutableMapping[Any, Any]]:
+        """Expand a record by extracting items from a nested array field."""
+        if not self._expand_path:
+            yield record
+            return
+
+        parent_record = record
+        expand_path = [path.eval(self.config) for path in self._expand_path]
+        expanded_any = False
+
+        if "*" in expand_path:
+            extracted: Any = dpath.values(parent_record, expand_path)
+            for record in extracted:
+                if isinstance(record, list):
+                    for item in record:
+                        if isinstance(item, dict):
+                            expanded_record = dict(item)
+                            self._apply_parent_context(parent_record, expanded_record)
+                            yield expanded_record
+                            expanded_any = True
+                        else:
+                            yield item
+                            expanded_any = True
+        else:
+            try:
+                extracted = dpath.get(parent_record, expand_path)
+            except KeyError:
+                extracted = None
+
+            if isinstance(extracted, list):
+                for item in extracted:
+                    if isinstance(item, dict):
+                        expanded_record = dict(item)
+                        self._apply_parent_context(parent_record, expanded_record)
+                        yield expanded_record
+                        expanded_any = True
+                    else:
+                        yield item
+                        expanded_any = True
+
+        if not expanded_any and self.on_no_records == "emit_parent":
+            yield parent_record
+
+    def _apply_parent_context(
+        self, parent_record: Mapping[str, Any], child_record: MutableMapping[str, Any]
+    ) -> None:
+        """Apply parent context to a child record."""
+        if self.remain_original_record:
+            child_record["original_record"] = parent_record
+
+        for field_mapping in self.parent_fields_to_copy:
+            field_mapping.copy_field(parent_record, child_record)

airbyte_cdk/sources/declarative/extractors/dpath_extractor.py

@@ -3,12 +3,13 @@
 #
 
 from dataclasses import InitVar, dataclass, field
-from typing import Any, Iterable, List, Mapping, MutableMapping, Union
+from typing import Any, Iterable, List, Mapping, MutableMapping, Optional, Union
 
 import dpath
 import requests
 
 from airbyte_cdk.sources.declarative.decoders import Decoder, JsonDecoder
+from airbyte_cdk.sources.declarative.expanders.record_expander import RecordExpander
 from airbyte_cdk.sources.declarative.extractors.record_extractor import RecordExtractor
 from airbyte_cdk.sources.declarative.interpolation.interpolated_string import InterpolatedString
 from airbyte_cdk.sources.types import Config
@@ -24,6 +25,11 @@ class DpathExtractor(RecordExtractor):
     If the field path points to an empty object, an empty array is returned.
     If the field path points to a non-existing path, an empty array is returned.
 
+    Optionally, records can be expanded by providing a RecordExpander component.
+    When record_expander is configured, each extracted record is passed through the
+    expander which extracts items from nested array fields and emits each item as a
+    separate record.
+
     Examples of instantiating this transform:
     ```
       extractor:
@@ -47,16 +53,32 @@ class DpathExtractor(RecordExtractor):
         field_path: []
     ```
 
+    ```
+      extractor:
+        type: DpathExtractor
+        field_path:
+          - "data"
+          - "object"
+        record_expander:
+          type: RecordExpander
+          expand_records_from_field:
+            - "lines"
+            - "data"
+          remain_original_record: true
+    ```
+
     Attributes:
         field_path (Union[InterpolatedString, str]): Path to the field that should be extracted
         config (Config): The user-provided configuration as specified by the source's spec
         decoder (Decoder): The decoder responsible to transfom the response in a Mapping
+        record_expander (Optional[RecordExpander]): Optional component to expand records by extracting items from nested array fields
     """
 
     field_path: List[Union[InterpolatedString, str]]
     config: Config
     parameters: InitVar[Mapping[str, Any]]
     decoder: Decoder = field(default_factory=lambda: JsonDecoder(parameters={}))
+    record_expander: Optional[RecordExpander] = None
 
     def __post_init__(self, parameters: Mapping[str, Any]) -> None:
         self._field_path = [
@@ -79,8 +101,15 @@ def extract_records(self, response: requests.Response) -> Iterable[MutableMappin
                 else:
                     extracted = dpath.get(body, path, default=[])  # type: ignore # extracted will be a MutableMapping, given input data structure
             if isinstance(extracted, list):
-                yield from extracted
+                if not self.record_expander:
+                    yield from extracted
+                else:
+                    for record in extracted:
+                        yield from self.record_expander.expand_record(record)
             elif extracted:
-                yield extracted
+                if self.record_expander:
+                    yield from self.record_expander.expand_record(extracted)
+                else:
+                    yield extracted
             else:
                 yield from []