Render Timing and Logging¶

Two development aids: how long a form took to render, and the library's log messages.

Render timing¶

Use render timing options to inspect form performance during development.

Timing behavior¶

The renderer measures render duration internally and can expose it in two ways:

Inline timing text in form output (show_timing=True)
Debug panel timing metadata (debug=True)

Inline timing (`show_timing=True`)¶

from pydantic_schemaforms import render_form_html

html = render_form_html(
    MyForm,
    submit_url="/submit",
    show_timing=True,
)

This adds a small timing indicator in the rendered form markup.

Debug panel (`debug=True`)¶

html = render_form_html(
    MyForm,
    submit_url="/submit",
    debug=True,
)

This appends a richer debug panel that includes timing plus schema/render metadata.

Combined usage¶

html = render_form_html(
    MyForm,
    submit_url="/submit",
    show_timing=True,
    debug=True,
)

Use this combination for local diagnosis of slow forms.

Async usage¶

The same options are available in async mode:

from pydantic_schemaforms import render_form_html_async

html = await render_form_html_async(
    MyForm,
    submit_url="/submit",
    show_timing=True,
)

With logging¶

If you also want log output, enable it explicitly:

html = render_form_html(
    MyForm,
    submit_url="/submit",
    show_timing=True,
    enable_logging=True,
)

enable_logging=True controls debug log emission and is independent of timing display in HTML.

Tips¶

Keep show_timing=False and debug=False for production-facing pages.
Use representative data when benchmarking complex forms (nested models, model lists, layout-heavy schemas).

Logging¶

pydantic-schemaforms uses Python's standard logging module and keeps detailed renderer logs opt-in.

What is logged by default¶

Default behavior for rendering calls:

No per-render debug/timing log lines are emitted.
Form rendering still works normally with no logging setup.

This keeps production output quiet unless you opt in.

Enabling renderer logs¶

Use enable_logging=True on render calls:

from pydantic_schemaforms import render_form_html

html = render_form_html(
    MyForm,
    submit_url="/submit",
    enable_logging=True,
)

When enabled, the renderer emits debug lines such as render duration and model name.

Logging level configuration¶

Renderer logs are emitted at DEBUG level. Configure logging accordingly:

import logging

logging.basicConfig(level=logging.DEBUG)

If your app is set to INFO/WARNING, DEBUG lines will remain hidden.

Per-request debugging pattern¶

For web apps, conditionally enable logs during troubleshooting:

from fastapi import FastAPI, Query
from fastapi.responses import HTMLResponse
from pydantic_schemaforms import SafeHTML, html, render_form_html

app = FastAPI()


@app.get("/demo", response_class=HTMLResponse)
def demo(debug_logs: bool = Query(False)):
    form_html = SafeHTML(render_form_html(
        MyForm,
        submit_url="/demo",
        enable_logging=debug_logs,
    ))
    return html(t"<html><body>{form_html}</body></html>")

show_timing=True: displays render timing in the returned HTML.
debug=True: appends the renderer debug panel to returned HTML.
enable_logging=True: emits renderer debug log lines.

These options are independent and can be combined.

Security guidance¶

Avoid logging raw secrets (CSRF tokens, passwords, session IDs).
Prefer logging outcomes and context (route, request_id, user_id) over sensitive payload values.