refactor: add pagination on folders

src/backend/base/langflow/api/v1/flows.py

@@ -11,6 +11,8 @@
 from fastapi import APIRouter, Depends, File, HTTPException, UploadFile
 from fastapi.encoders import jsonable_encoder
 from fastapi.responses import StreamingResponse
+from fastapi_pagination import Page, Params, add_pagination
+from fastapi_pagination.ext.sqlalchemy import paginate
 from loguru import logger
 from sqlmodel import Session, and_, col, select
 
@@ -19,6 +21,7 @@
 from langflow.initial_setup.setup import STARTER_FOLDER_NAME
 from langflow.services.auth.utils import get_current_active_user
 from langflow.services.database.models.flow import Flow, FlowCreate, FlowRead, FlowUpdate
+from langflow.services.database.models.flow.model import FlowHeader
 from langflow.services.database.models.flow.utils import get_webhook_component_in_flow
 from langflow.services.database.models.folder.constants import DEFAULT_FOLDER_NAME
 from langflow.services.database.models.folder.model import Folder
@@ -120,64 +123,80 @@ def create_flow(
         raise HTTPException(status_code=500, detail=str(e)) from e
 
 
-@router.get("/", response_model=list[FlowRead], status_code=200)
+@router.get("/", response_model=list[FlowRead] | Page[FlowRead] | list[FlowHeader], status_code=200)
 def read_flows(
     *,
     current_user: User = Depends(get_current_active_user),
     session: Session = Depends(get_session),
     settings_service: SettingsService = Depends(get_settings_service),
     remove_example_flows: bool = False,
     components_only: bool = False,
+    get_all: bool = False,
+    folder_id: UUID | None = None,
+    params: Params = Depends(),
+    header_flows: bool = False,
 ):
     """
-    Retrieve a list of flows.
+    Retrieve a list of flows with pagination support.
 
     Args:
         current_user (User): The current authenticated user.
         session (Session): The database session.
         settings_service (SettingsService): The settings service.
-        remove_example_flows (bool, optional): Whether to remove example flows. Defaults to False.
         components_only (bool, optional): Whether to return only components. Defaults to False.
-
+        get_all (bool, optional): Whether to return all flows without pagination. Defaults to False.
+        folder_id (UUID, optional): The folder ID. Defaults to None.
+        params (Params): Pagination parameters.
+        remove_example_flows (bool, optional): Whether to remove example flows. Defaults to False.
     Returns:
-        List[Dict]: A list of flows in JSON format.
+        Union[list[FlowRead], Page[FlowRead]]: A list of flows or a paginated response containing the list of flows.
     """
 
     try:
         auth_settings = settings_service.auth_settings
+
+        default_folder = session.exec(select(Folder).where(Folder.name == DEFAULT_FOLDER_NAME)).first()
+        default_folder_id = default_folder.id if default_folder else None
+
+        starter_folder = session.exec(select(Folder).where(Folder.name == STARTER_FOLDER_NAME)).first()
+        starter_folder_id = starter_folder.id if starter_folder else None
+
+        if not folder_id:
+            folder_id = default_folder_id
+
         if auth_settings.AUTO_LOGIN:
             stmt = select(Flow).where(
                 (Flow.user_id == None) | (Flow.user_id == current_user.id)  # noqa
             )
-            if components_only:
-                stmt = stmt.where(Flow.is_component == True)  # noqa
-            flows = session.exec(stmt).all()
-
         else:
-            flows = current_user.flows
+            stmt = select(Flow).where(Flow.user_id == current_user.id)
+
+        if remove_example_flows:
+            stmt = stmt.where(Flow.folder_id != starter_folder_id)
 
-        flows = validate_is_component(flows)  # type: ignore
         if components_only:
-            flows = [flow for flow in flows if flow.is_component]
-        flow_ids = [flow.id for flow in flows]
-        # with the session get the flows that DO NOT have a user_id
-        folder = session.exec(select(Folder).where(Folder.name == STARTER_FOLDER_NAME)).first()
-
-        if not remove_example_flows and not components_only:
-            try:
-                example_flows = folder.flows if folder else []
-                for example_flow in example_flows:
-                    if example_flow.id not in flow_ids:
-                        flows.append(example_flow)  # type: ignore
-            except Exception as e:
-                logger.error(e)
+            stmt = stmt.where(Flow.is_component == True)  # noqa
 
-        if remove_example_flows:
-            flows = [flow for flow in flows if flow.folder_id != folder.id]
+        if not get_all:
+            stmt = stmt.where(Flow.folder_id == folder_id)
+
+        if get_all:
+            flows = session.exec(stmt).all()
+            flows = validate_is_component(flows)  # type: ignore
+            if components_only:
+                flows = [flow for flow in flows if flow.is_component]
+            if remove_example_flows and starter_folder_id:
+                flows = [flow for flow in flows if flow.folder_id != starter_folder_id]
+            if header_flows:
+                return [
+                    {"id": flow.id, "name": flow.name, "folder_id": flow.folder_id, "is_component": flow.is_component}
+                    for flow in flows
+                ]  # type: ignore
+            return flows
+        return paginate(session, stmt, params=params)
 
     except Exception as e:
         raise HTTPException(status_code=500, detail=str(e)) from e
-    return [jsonable_encoder(flow) for flow in flows]
 
 
 @router.get("/{flow_id}", response_model=FlowRead, status_code=200)
@@ -399,3 +418,35 @@ async def download_multiple_file(
             headers={"Content-Disposition": f"attachment; filename={filename}"},
         )
     return flows_without_api_keys[0]
+
+
+@router.get("/basic_examples/", response_model=list[FlowRead], status_code=200)
+def read_basic_examples(
+    *,
+    session: Session = Depends(get_session),
+):
+    """
+    Retrieve a list of basic example flows.
+
+    Args:
+        session (Session): The database session.
+
+    Returns:
+        list[FlowRead]: A list of basic example flows.
+    """
+
+    try:
+        # Get the starter folder
+        starter_folder = session.exec(select(Folder).where(Folder.name == STARTER_FOLDER_NAME)).first()
+
+        if not starter_folder:
+            return []
+
+        # Get all flows in the starter folder
+        return session.exec(select(Flow).where(Flow.folder_id == starter_folder.id)).all()
+
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e)) from e
+
+
+add_pagination(router)

src/backend/base/langflow/api/v1/folders.py

@@ -1,5 +1,7 @@
 import orjson
 from fastapi import APIRouter, Depends, File, HTTPException, Response, UploadFile, status
+from fastapi_pagination import Params
+from fastapi_pagination.ext.sqlmodel import paginate
 from sqlalchemy import or_, update
 from sqlmodel import Session, select
 
@@ -8,16 +10,17 @@
 from langflow.api.v1.schemas import FlowListCreate, FlowListReadWithFolderName
 from langflow.helpers.flow import generate_unique_flow_name
 from langflow.helpers.folders import generate_unique_folder_name
+from langflow.initial_setup.setup import STARTER_FOLDER_NAME
 from langflow.services.auth.utils import get_current_active_user
 from langflow.services.database.models.flow.model import Flow, FlowCreate, FlowRead
 from langflow.services.database.models.folder.constants import DEFAULT_FOLDER_NAME
 from langflow.services.database.models.folder.model import (
     Folder,
     FolderCreate,
     FolderRead,
-    FolderReadWithFlows,
     FolderUpdate,
 )
+from langflow.services.database.models.folder.pagination_model import FolderWithPaginatedFlows
 from langflow.services.database.models.user.model import User
 from langflow.services.deps import get_session
 
@@ -89,25 +92,42 @@ def read_folders(
                 or_(Folder.user_id == current_user.id, Folder.user_id == None)  # type: ignore # noqa: E711
             )
         ).all()
+        folders = [folder for folder in folders if folder.name != STARTER_FOLDER_NAME]
         return sorted(folders, key=lambda x: x.name != DEFAULT_FOLDER_NAME)
     except Exception as e:
         raise HTTPException(status_code=500, detail=str(e)) from e
 
 
-@router.get("/{folder_id}", response_model=FolderReadWithFlows, status_code=200)
+@router.get("/{folder_id}", response_model=FolderWithPaginatedFlows, status_code=200)
 def read_folder(
     *,
     session: Session = Depends(get_session),
     folder_id: str,
     current_user: User = Depends(get_current_active_user),
+    params: Params = Depends(),
+    is_component: bool = False,
+    is_flow: bool = False,
+    search: str = "",
 ):
     try:
         folder = session.exec(select(Folder).where(Folder.id == folder_id, Folder.user_id == current_user.id)).first()
         if not folder:
             raise HTTPException(status_code=404, detail="Folder not found")
-        flows_from_current_user_in_folder = [flow for flow in folder.flows if flow.user_id == current_user.id]
-        folder.flows = flows_from_current_user_in_folder
-        return folder
+
+        stmt = (
+            select(Flow)
+            .where(Flow.folder_id == folder_id, Flow.user_id == current_user.id)
+            .order_by(Flow.updated_at.desc())  # type: ignore
+        )
+        if is_component:
+            stmt = stmt.where(Flow.is_component == True)  # type: ignore # noqa: E712
+        if is_flow:
+            stmt = stmt.where(Flow.is_component == False)  # type: ignore # noqa: E712
+        if search:
+            stmt = stmt.where(Flow.name.like(f"%{search}%"))  # type: ignore
+        paginated_flows = paginate(session, stmt, params=params)
+
+        return FolderWithPaginatedFlows(folder=FolderRead.model_validate(folder), flows=paginated_flows)
     except Exception as e:
         if "No result found" in str(e):
             raise HTTPException(status_code=404, detail="Folder not found") from e

src/backend/base/langflow/services/database/models/flow/model.py

@@ -9,7 +9,7 @@
 from emoji import purely_emoji  # type: ignore
 from fastapi import HTTPException, status
 from loguru import logger
-from pydantic import field_serializer, field_validator
+from pydantic import BaseModel, field_serializer, field_validator
 from sqlalchemy import Text, UniqueConstraint
 from sqlmodel import JSON, Column, Field, Relationship, SQLModel
 
@@ -188,6 +188,20 @@ class FlowRead(FlowBase):
     folder_id: UUID | None = Field()
 
 
+class FlowHeader(BaseModel):
+    id: UUID
+    name: str
+    folder_id: UUID | None = Field()
+    is_component: bool | None = Field()
+
+
+class PaginatedFlowResponse(BaseModel):
+    flows: list[FlowRead]
+    total: int
+    page_size: int
+    page_index: int
+
+
 class FlowUpdate(SQLModel):
     name: str | None = None
     description: str | None = None

src/backend/base/langflow/services/database/models/folder/pagination_model.py

@@ -0,0 +1,10 @@
+from fastapi_pagination import Page
+
+from langflow.helpers.base_model import BaseModel
+from langflow.services.database.models.flow.model import Flow
+from langflow.services.database.models.folder.model import FolderRead
+
+
+class FolderWithPaginatedFlows(BaseModel):
+    folder: FolderRead
+    flows: Page[Flow]

src/backend/base/pyproject.toml

@@ -282,7 +282,8 @@ dependencies = [
     "spider-client>=0.0.27",
     "diskcache>=5.6.3",
     "clickhouse-connect==0.7.19",
-    "assemblyai>=0.33.0"
+    "assemblyai>=0.33.0",
+    "fastapi-pagination>=0.12.29",
 ]
 
 # Optional dependencies for uv

src/backend/tests/unit/test_database.py

@@ -67,8 +67,30 @@ async def test_read_flows(client: TestClient, json_flow: str, active_user, logge
     assert len(response.json()) > 0
 
 
+async def test_read_flows_pagination(client: TestClient, json_flow: str, active_user, logged_in_headers):
+    response = await client.get("api/v1/flows/", headers=logged_in_headers)
+    assert response.status_code == 200
+    assert response.json()["page"] == 1
+    assert response.json()["size"] == 50
+    assert response.json()["pages"] == 0
+    assert response.json()["total"] == 0
+    assert len(response.json()["items"]) == 0
+
+
+async def test_read_flows_pagination_with_params(client: TestClient, json_flow: str, active_user, logged_in_headers):
+    response = await client.get("api/v1/flows/", headers=logged_in_headers, params={"page": 3, "size": 10})
+    assert response.status_code == 200
+    assert response.json()["page"] == 3
+    assert response.json()["size"] == 10
+    assert response.json()["pages"] == 0
+    assert response.json()["total"] == 0
+    assert len(response.json()["items"]) == 0
+
+
 async def test_read_flows_components_only(client: TestClient, flow_component: dict, logged_in_headers):
-    response = await client.get("api/v1/flows/", headers=logged_in_headers, params={"components_only": True})
+    response = await client.get(
+        "api/v1/flows/", headers=logged_in_headers, params={"components_only": True, "get_all": True}
+    )
     assert response.status_code == 200
     names = [flow["name"] for flow in response.json()]
     assert any("Chat Input Component" in name for name in names)
@@ -267,6 +289,52 @@ async def test_delete_folder_with_flows_with_transaction_and_build(
         assert response.json() == {"vertex_builds": {}}
 
 
+async def test_get_flows_from_folder_pagination(client: TestClient, logged_in_headers):
+    # Create a new folder
+    folder_name = f"Test Folder {uuid4()}"
+    folder = FolderCreate(name=folder_name, description="Test folder description", components_list=[], flows_list=[])
+
+    response = await client.post("api/v1/folders/", json=folder.model_dump(), headers=logged_in_headers)
+    assert response.status_code == 201, f"Expected status code 201, but got {response.status_code}"
+
+    created_folder = response.json()
+    folder_id = created_folder["id"]
+
+    response = await client.get(f"api/v1/folders/{folder_id}", headers=logged_in_headers)
+    assert response.status_code == 200
+    assert response.json()["folder"]["name"] == folder_name
+    assert response.json()["folder"]["description"] == "Test folder description"
+    assert response.json()["flows"]["page"] == 1
+    assert response.json()["flows"]["size"] == 50
+    assert response.json()["flows"]["pages"] == 0
+    assert response.json()["flows"]["total"] == 0
+    assert len(response.json()["flows"]["items"]) == 0
+
+
+async def test_get_flows_from_folder_pagination_with_params(client: TestClient, logged_in_headers):
+    # Create a new folder
+    folder_name = f"Test Folder {uuid4()}"
+    folder = FolderCreate(name=folder_name, description="Test folder description", components_list=[], flows_list=[])
+
+    response = await client.post("api/v1/folders/", json=folder.model_dump(), headers=logged_in_headers)
+    assert response.status_code == 201, f"Expected status code 201, but got {response.status_code}"
+
+    created_folder = response.json()
+    folder_id = created_folder["id"]
+
+    response = await client.get(
+        f"api/v1/folders/{folder_id}", headers=logged_in_headers, params={"page": 3, "size": 10}
+    )
+    assert response.status_code == 200
+    assert response.json()["folder"]["name"] == folder_name
+    assert response.json()["folder"]["description"] == "Test folder description"
+    assert response.json()["flows"]["page"] == 3
+    assert response.json()["flows"]["size"] == 10
+    assert response.json()["flows"]["pages"] == 0
+    assert response.json()["flows"]["total"] == 0
+    assert len(response.json()["flows"]["items"]) == 0
+
+
 async def test_create_flows(client: TestClient, session: Session, json_flow: str, logged_in_headers):
     flow = orjson.loads(json_flow)
     data = flow["data"]
@@ -412,7 +480,7 @@ async def test_delete_nonexistent_flow(client: TestClient, active_user, logged_i
 
 
 async def test_read_only_starter_projects(client: TestClient, active_user, logged_in_headers):
-    response = await client.get("api/v1/flows/", headers=logged_in_headers)
+    response = await client.get("api/v1/flows/basic_examples/", headers=logged_in_headers)
     starter_projects = load_starter_projects()
     assert response.status_code == 200
     assert len(response.json()) == len(starter_projects)

src/frontend/src/App.css

@@ -153,6 +153,7 @@ body {
   width: 100%;
   height: 100%;
 }
+
 .react-flow__resize-control.handle {
   width: 0.75rem !important;
   height: 0.75rem !important;