Switch Operations¶

path, method and base_url are parameters, so one form can serve any operation in the document it was constructed with. Setting path or method rebuilds the widgets; setting base_url redirects the next request.

A form rebuilt for a different Petstore operation

Change both at once¶

form.param.update(path="/pet", method="post")

Use param.update rather than two assignments. Two assignments rebuild twice, and the intermediate pair, e.g. the old path with the new method, is often an operation the document does not define, which renders an error on the way past.

Rebuilt in place¶

form.form and form.response are the same objects before and after, mutated rather than replaced, so a layout built once keeps working:

layout = pmui.Column(form.form)   # built once
form.method = "post"              # layout now shows the POST widgets

The previous response is cleared on rebuild, since it does not describe the new operation.

A selector over several operations¶

"""One form, repointed at any operation in the document."""

import panel as pn
import panel_material_ui as pmui

from panel_openapi import OpenAPIForm
from panel_openapi import load_openapi

pn.extension()

SPEC = load_openapi("https://petstore3.swagger.io/api/v3/openapi.json")
BASE_URL = "https://petstore3.swagger.io/api/v3"

OPERATIONS = {
    "Find pets by status": ("/pet/findByStatus", "get"),
    "Get a pet by id": ("/pet/{petId}", "get"),
    "Add a pet": ("/pet", "post"),
    "Place an order": ("/store/order", "post"),
}

form = OpenAPIForm(SPEC, base_url=BASE_URL, path="/pet/findByStatus", method="get")

selector = pmui.Select(label="Operation", options=list(OPERATIONS), value="Find pets by status")


def repoint(event):
    path, method = OPERATIONS[event.new]
    # Update both at once: one rebuild, and no transient path/method pair the
    # document does not define.
    form.param.update(path=path, method=method)


selector.param.watch(repoint, "value")

pmui.Column(selector, form, sizing_mode="stretch_width").servable(title="Switch operation")

Undefined targets¶

Setting a path or method the document does not define renders an error listing what is available, and leaves form.widgets empty. Setting a valid one restores the form, so a selector that passes through an invalid combination recovers.

Redirecting requests¶

base_url is read when the request is built, so pointing a form at staging instead of production needs nothing else:

form.base_url = "https://staging.example.com"

Reacting to changes¶

title updates with the operation unless you set it explicitly, and it is a parameter, so it can drive a heading:

pmui.Typography(form.param.title, variant="h6")

pmui.Page.title is a plain string parameter and cannot take a reference, so sync it with a watcher instead:

form.param.watch(lambda event: setattr(page, "title", event.new), "title")