wizard-ui-bridge

wizard-ui-bridge is the user-interface-independent way for a wizard to ask a user questions.

A wizard asks a series of questions and turns the answers into something, often a configuration file. WizardUiBridge is the interface it asks through, so the same wizard runs on a plain console, on a full-screen Textual user interface, in a graphical user interface (Tkinter through the companion package below, or a toolkit you write a bridge for yourself), or on a scripted bridge in your tests.

Tk companion

wizard-ui-bridge has a companion wizard-tk-bridge that implements the same user-interface-independent way for a wizard to ask a user questions using a Tkinter GUI.

Is this package for you?

This package is a good fit when one or more of these apply:

• You have a wizard, or a program that asks a user a series of questions, and you do not want the questions to be tied to one user interface.
• You want typed questions, each with validation and re-asking: text, integer, path, yes/no, choice and multi-choice asked one at a time, and float, date, time, date and time and duration as fields of a form.
• You want to ask a whole form at once where the user interface can show one, and fall back to one question at a time where it cannot.
• You want the user to be able to go back a step or cancel, without every question having to handle that.
• You want a full-screen text user interface for free when the program runs in a terminal, and a plain console fallback when it does not.
• You want your wizard to be testable without a terminal.

This package is probably not the right one when:

• You want a general widget toolkit. Use Textual or a GUI toolkit directly.
• You only need one input() call.

Installation

wizard-ui-bridge requires Python 3.12 or newer.

pip install --upgrade wizard-ui-bridge

Textual is optional. Install it with the extra when you want the full-screen text user interface:

pip install --upgrade 'wizard-ui-bridge[textual]'

Without the extra, everything except the Textual bridge works, and make_text_ui_bridge() returns the console bridge. Importing wizard_ui_bridge never imports Textual; it is imported the first time a Textual bridge is actually used. Asking for the Textual bridge without Textual installed raises ImportError naming the extra to install.

Quick start

Ask a small form, on the best user interface the terminal allows:

import sys

from wizard_ui_bridge import AskTextField, AskIntField, AskYesNoField, \
    make_text_ui_bridge

bridge = make_text_ui_bridge(sys.stdout, sys.stdin, sys.stderr)
answers = bridge.ask_form('Describe the export', [
    AskTextField('Report name', 'Shown as the title of the report'),
    AskIntField('Rows', 'How many rows to export', min_value=1),
    AskYesNoField('Headings', 'Write a heading row', True)])
for answer in answers:
    print(f'{answer.asking.short_question}: {answer.value}')

The same code runs as a full-screen form when Textual is installed and the program runs in a terminal, and as one console question at a time when it does not.

Ask one question at a time instead:

name = bridge.ask_text('Report name', default='report')
rows = bridge.ask_int('Rows', min_value=1)

Main entry points

• WizardUiBridge The bridge a wizard asks through. Subclass it to connect a wizard to a user interface of your own; the base class turns the typed questions and whole-form questions into the few methods your subclass implements.

• make_text_ui_bridge() and UiBridgeType Return the Textual bridge when Textual is installed and both streams are a terminal, and the console bridge otherwise. UiBridgeType forces one or the other.

• WizardUiBridgeConsole Asks one question at a time on plain text streams.

• WizardUiBridgeTextual Full-screen text user interface, needs the textual extra.

• AskTextField, AskIntField, AskFloatField, AskPathField, AskYesNoField, AskChoiceField, AskMultiChoiceField, AskDateField, AskTimeField, AskDateTimeField, AskDurationField The typed fields a form is built from, each with a matching Answer...Field.

• WizardBack, WizardAbort, WizardCancelLevel, WizardNavigation How a user asks to go back a step or to give up, without every question having to handle it.

• TableColumn, TableCell and ask_table() Ask for a small table of values, with a fixed or variable number of rows.

• textual_installed() and load_textual_bridge() Ask whether the optional Textual bridge can be used, and get the class when it can.

Writing your own bridge

A bridge of your own subclasses WizardUiBridge and implements the few asking methods. The modules wizard_ui_bridge.bridge_helpers and wizard_ui_bridge.form_helpers hold the helpers the bundled bridges use to interpret raw answers and to build form answers, so that a bridge of your own behaves the same way.

History

The low-level WizardUiBridge.ask() method was removed in version 1.2, together with the fallbacks that let a bridge which only overrode ask() keep working by rerouting the typed ask_*() calls through it. Version 1.1 was the last version that supported it. A bridge implements the typed methods directly: ask_text(), ask_choice(), ask_multi(), ask_yes_no() and ask_table(), together with show(). A typed method a bridge does not implement raises NotImplementedError. See Writing your own bridge above.

Relation to tableio-cfg-json

This package used to be part of tableio-cfg-json. It was split out so that a wizard that has nothing to do with TableIO does not have to install TableIO and everything TableIO depends on.

Source code repo history

The two git repos https://github.com/tom-bjorkholm/wizard-ui-bridge and https://github.com/tom-bjorkholm/tableio_cfg_json share a common history. Up until version 1.1 there was only one repo. Now that repo is split in two, and each repo holds only code for its package. However, both repos have the common history.

Documentation

• Teaching examples and walkthroughs: wizard_ui_bridge/example/src/wizard_ui_example

• Public API notes: doc/wizard_ui_bridge_api.md

• Protected/internal API notes: doc/wizard_ui_bridge_protected_api.md

• Source repository: wizard-ui-bridge

License

MIT

Test summary

• Test result: 1051 passed, 9 deselected in 38s
• No flake8 warnings.
• No mypy errors found.
• No pylint warnings.
• No python layout warnings.
• Built version(s): 1.3
• Build and test using Python 3.14.6