From afee4f36ce5c753f1257b153497daa09bf211cdb Mon Sep 17 00:00:00 2001
From: oryx1729 <78848855+oryx1729@users.noreply.github.com>
Date: Wed, 23 Jun 2021 12:01:54 +0200
Subject: [PATCH] Add scaffold for defining custom components for Pipelines
 (#1205)

---
 rest_api/config.py                     |  2 +-
 rest_api/controller/__init__.py        |  1 +
 rest_api/pipeline/custom_component.py  | 17 +++++++++++++++++
 rest_api/{ => pipeline}/pipelines.yaml |  0
 4 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 rest_api/pipeline/custom_component.py
 rename rest_api/{ => pipeline}/pipelines.yaml (100%)

diff --git a/rest_api/config.py b/rest_api/config.py
index 72fb0f0d5..56e1e7675 100644
--- a/rest_api/config.py
+++ b/rest_api/config.py
@@ -1,6 +1,6 @@
 import os
 
-PIPELINE_YAML_PATH = os.getenv("PIPELINE_YAML_PATH", "rest_api/pipelines.yaml")
+PIPELINE_YAML_PATH = os.getenv("PIPELINE_YAML_PATH", "rest_api/pipeline/pipelines.yaml")
 QUERY_PIPELINE_NAME = os.getenv("QUERY_PIPELINE_NAME", "query")
 INDEXING_PIPELINE_NAME = os.getenv("INDEXING_PIPELINE_NAME", "indexing")
 
diff --git a/rest_api/controller/__init__.py b/rest_api/controller/__init__.py
index e69de29bb..4b066366a 100644
--- a/rest_api/controller/__init__.py
+++ b/rest_api/controller/__init__.py
@@ -0,0 +1 @@
+from rest_api.pipeline import custom_component  # this import is required for the Custom Components to be registered
diff --git a/rest_api/pipeline/custom_component.py b/rest_api/pipeline/custom_component.py
new file mode 100644
index 000000000..35dfd97af
--- /dev/null
+++ b/rest_api/pipeline/custom_component.py
@@ -0,0 +1,17 @@
+"""
+Pipelines allow putting together Components to build a graph.
+
+In addition to the standard Haystack Components, custom user-defined Components
+can be used in a Pipeline YAML configuration.
+
+The classes for the Custom Components must be defined in this file.
+"""
+
+
+from haystack import BaseComponent
+
+
+class SampleComponent(BaseComponent):
+
+    def run(self, **kwargs):
+        raise NotImplementedError
diff --git a/rest_api/pipelines.yaml b/rest_api/pipeline/pipelines.yaml
similarity index 100%
rename from rest_api/pipelines.yaml
rename to rest_api/pipeline/pipelines.yaml