"""Test helpers to configure an app that tests many cases (single/multiple outputs, patterns, multi triggers, ...). """ import json from functools import wraps from pathlib import Path from typing import Union import dash from dash import html import flask from dash import Dash, no_update from dash.dependencies import MATCH, ALL, ALLSMALLER, Input, Output, State from dash.development.base_component import Component from flask import request from django_plotly_dash import DjangoDash dash_contract_data = Path(__file__).with_suffix(".json") def fill_in_test_app(app: Union[DjangoDash, Dash], write=False): """Takes an unitialized Dash (or DjangoDash) app and add dash components and callbacks to test - single/multiple outputs - patterns (ALL,ALLSMALLER,MATCH) - multi triggers :param app: the Dash/DjangoDash app to initialize with components and callbacks :param write: if True, it will record/log in the tests_dash_contract.json all client callbacks to the app :return: None """ # define decorator that logs the body/response if write==True if not write: log_body_response = lambda f: f else: record_session = dash_contract_data.open("w") record_session.write("[") def log_body_response(f): @wraps(f) def wrapper(*args, **kwargs): result = f(*args, **kwargs) record_session.write( json.dumps( { "body": flask.request.get_json(), "args": args, "kwargs": kwargs, "result": result, } ) ) record_session.write(",") return result return wrapper def add_outputs_multi(): """Test output format (in list or not)""" inp1 = html.Button("Multi-single-output", id="inp1") outs = [html.Div(id=f"out1-{i}") for i in range(4)] app.layout.children.append(html.Div([inp1] + outs)) @app.callback( Output(outs[0].id, "children"), [Input(inp1.id, "n_clicks_timestamp")], [State(inp1.id, "n_clicks")], ) @log_body_response def test_single_output(*args): return f"single - {args}" @app.callback( [Output(outs[1].id, "children")], [Input(inp1.id, "n_clicks_timestamp")], [State(inp1.id, "n_clicks")], ) @log_body_response def test_single_output_list(*args): return [f"single in list - {args}"] @app.callback( [Output(outs[2].id, "children"), Output(outs[3].id, "children")], [Input(inp1.id, "n_clicks_timestamp")], [State(inp1.id, "n_clicks")], ) @log_body_response def test_multi_output(*args): return [f"multi in list - {args}"] * 2 def add_update_state_in_output(): inp1b = html.Button("Input-update-output-state", id="inp1b") out1b = html.A(href="http://www.example.com/null", id="out1b") app.layout.children.append(html.Div([inp1b, out1b])) @app.callback( [Output(out1b.id, "href"), Output(out1b.id, "children"), ], [Input(inp1b.id, "n_clicks_timestamp")], ) @log_body_response def test_update_output_state(n_clicks_timestamp): return f"http://www.example.com/{n_clicks_timestamp}", f"http://www.example.com/{n_clicks_timestamp}" def add_multi_triggered(): """Test a callback getting more than one element in the triggered context""" inp1 = html.Button("Multiple triggered", id="inp2") outs = [html.Div(id=f"out2-{i}") for i in range(1)] app.layout.children.append(html.Div([inp1] + outs)) @app.callback( Output(outs[0].id, "children"), [Input(inp1.id, "n_clicks_timestamp"), Input(inp1.id, "n_clicks")], ) @log_body_response def test_single_output(*args, **kwargs): print(kwargs) return f"multi triggered - {args} - {dash.callback_context.triggered or []}" def add_pattern_all(): inps = [ html.Button(f"Pattern ALL {i}", id={"_id": f"inp-{i}", "_type": "btn3"}) for i in range(3) ] out = html.Div(id=f"out3") app.layout.children.append(html.Div(inps + [out])) @app.callback( Output(out.id, "children"), [Input({"_id": ALL, "_type": "btn3"}, "n_clicks_timestamp")], [State({"_id": ALL, "_type": "btn3"}, "n_clicks")], ) @log_body_response def test_single_output(*args): return f"pattern ALL - {args}" def add_pattern_allsmaller(): inps = [ html.Button(f"Pattern ALLSMALLER {i}", id={"_id": f"inp-{i}", "_type": "btn4"}) for i in range(3) ] out = html.Div(id=f"out4") app.layout.children.append(html.Div(inps + [out])) @app.callback( Output({"_id": MATCH, "_type": "btn4"}, "children"), [Input({"_id": ALLSMALLER, "_type": "btn4"}, "n_clicks")], [State({"_id": ALLSMALLER, "_type": "btn4"}, "id")], ) @log_body_response def test_single_output(*args): return f"pattern ALLSMALLER - {args}" def add_pattern_match(): inps = [ html.Button(f"Pattern MATCH {i}", id={"_id": f"inp-{i}", "_type": "btn5"}) for i in range(3) ] out = html.Div(id=f"out5") app.layout.children.append(html.Div(inps + [out])) @app.callback( Output({"_id": MATCH, "_type": "btn5"}, "children"), [Input({"_id": MATCH, "_type": "btn5"}, "n_clicks")], [State({"_id": MATCH, "_type": "btn5"}, "id")], ) @log_body_response def test_single_output(*args): return f"pattern MATCH - {args}" def add_stop(): app.layout.children.append(html.Button("stop", id="stop")) @app.callback(Output("stop", "children"), [Input("stop", "n_clicks")]) def stop_server(nclicks): if nclicks: if write: # close the file recording the session record_session.write("]") record_session.close() func = request.environ.get("werkzeug.server.shutdown") func() return no_update app.layout = html.Div([]) add_outputs_multi() add_update_state_in_output() add_multi_triggered() add_pattern_all() add_pattern_allsmaller() add_pattern_match() add_stop() # add to all elements a n_clicks/n_clicks_timestamp values to have populate_values detect properties i = 0 ts = 1611733453854 for comp in app.layout.children: for elem in comp.children: if isinstance(elem, Component): elem.n_clicks = i elem.n_clicks_timestamp = ts i += 1 ts += 100 if __name__ == "__main__": # to generate the test_dash_contract.json, run the pure Dash app and click on each button once successively # if you regenerate the test_dash_contract.json, the final assert of the test test_dash_stateful_app will fail # as the timestamp will be different => the test will have to be updated accordingly test_app = Dash("DashContractApp") fill_in_test_app(test_app, write=True) test_app.run_server(debug=True)