Adds ranker and setting of parameters in UI

app.py

@@ -37,9 +37,7 @@ def run_demo():
             styles={
                 "container": {"border": "2px solid #818494"},
                 "icon": {"font-size": "22px"},
-                # "nav-item": {},
                 "nav-link": {"font-size": "20px", "text-align": "left"},
-                # "nav-link-selected": {"background-color": "green"},
             },
         )
         component_select_pipeline(navigation)

core/pipelines.py

@@ -6,6 +6,7 @@ from haystack import Pipeline
 from haystack.document_stores import InMemoryDocumentStore
 from haystack.nodes.retriever import DensePassageRetriever, TfidfRetriever
 from haystack.nodes.preprocessor import PreProcessor
+from haystack.nodes.ranker import SentenceTransformersRanker
 
 
 def keyword_search(
@@ -72,3 +73,20 @@ def dense_passage_retrieval(
     )
 
     return search_pipeline, index_pipeline
+
+def dense_passage_retrieval_ranker(
+    index="documents",
+    query_embedding_model="facebook/dpr-question_encoder-single-nq-base",
+    passage_embedding_model="facebook/dpr-ctx_encoder-single-nq-base",
+    ranker_model="cross-encoder/ms-marco-MiniLM-L-12-v2"
+):
+    search_pipeline, index_pipeline = dense_passage_retrieval(
+        index=index,
+        query_embedding_model=query_embedding_model,
+        passage_embedding_model=passage_embedding_model,
+    )
+    ranker = SentenceTransformersRanker(model_name_or_path=ranker_model)
+    
+    search_pipeline.add_node(ranker, name="Ranker", inputs=["DPRRetriever"])
+    
+    return search_pipeline, index_pipeline

interface/components.py

@@ -4,7 +4,7 @@ from interface.draw_pipelines import get_pipeline_graph
 
 
 def component_select_pipeline(container):
-    pipeline_names, pipeline_funcs = get_pipelines()
+    pipeline_names, pipeline_funcs, pipeline_func_parameters = get_pipelines()
     with container:
         selected_pipeline = st.selectbox(
             "Select pipeline",
@@ -13,14 +13,29 @@ def component_select_pipeline(container):
             if "Keyword Search" in pipeline_names
             else 0,
         )
+        index_pipe = pipeline_names.index(selected_pipeline)
+        st.write("---")
+        st.header("Pipeline Parameters")
+        for parameter, value in pipeline_func_parameters[index_pipe].items():
+            if isinstance(value, str):
+                value = st.text_input(parameter, value)
+            elif isinstance(value, bool):
+                value = st.checkbox(parameter, value)
+            elif isinstance(value, int):
+                value = int(st.number_input(parameter, value))
+            elif isinstance(value, float):
+                value = float(st.number_input(parameter, value))
+            pipeline_func_parameters[index_pipe][parameter] = value
         if (
             st.session_state["pipeline"] is None
             or st.session_state["pipeline"]["name"] != selected_pipeline
+            or list(st.session_state["pipeline_func_parameters"][index_pipe].values()) != list(pipeline_func_parameters[index_pipe].values())
         ):
+            st.session_state["pipeline_func_parameters"] = pipeline_func_parameters
             (
                 search_pipeline,
                 index_pipeline,
-            ) = pipeline_funcs[pipeline_names.index(selected_pipeline)]()
+            ) = pipeline_funcs[index_pipe](**pipeline_func_parameters[index_pipe])
             st.session_state["pipeline"] = {
                 "name": selected_pipeline,
                 "search_pipeline": search_pipeline,

interface/config.py

@@ -1,7 +1,10 @@
 from interface.pages import page_landing_page, page_search, page_index
 
 # Define default Session Variables over the whole session.
-session_state_variables = {"pipeline": None}
+session_state_variables = {
+    "pipeline": None,
+    "pipeline_func_parameters": []
+}
 
 # Define Pages for the demo
 pages = {

interface/utils.py

@@ -1,6 +1,6 @@
 from io import StringIO
 import core.pipelines as pipelines_functions
-from inspect import getmembers, isfunction
+from inspect import getmembers, isfunction, signature
 from newspaper import Article
 from PyPDF2 import PdfFileReader
 import streamlit as st
@@ -16,7 +16,8 @@ def get_pipelines():
     pipeline_names = [
         " ".join([n.capitalize() for n in name.split("_")]) for name in pipeline_names
     ]
-    return pipeline_names, pipeline_funcs
+    pipeline_func_parameters = [{key: value.default for key, value in signature(pipe_func).parameters.items()} for pipe_func in pipeline_funcs]
+    return pipeline_names, pipeline_funcs, pipeline_func_parameters
 
 
 @st.experimental_memo