← Back to all products

Conditional Logic Engine

$29

Dynamic form behavior with 15 operators and 9 action types for show/hide/require/skip fields.

📁 10 files

JSONMarkdownPython

📄 Product Preview

Try the interactive reader and demo tools below, or get the full product with all content unlocked.

📖 Interactive Reader (Free Preview) ⚙ Try Demo Tools 📦 Download Free Sample

📁 File Structure 10 files

conditional-logic-engine/ ├── LICENSE ├── README.md ├── examples/ │ └── form_rules.json ├── free-sample.zip ├── guide/ │ ├── 01_features.md │ ├── 02_cli-reference.md │ ├── 03_programmatic-usage.md │ └── 04_license.md ├── index.html └── src/ └── conditional_logic_engine.py

📖 Documentation Preview README excerpt

Conditional Logic Engine

Dynamic form behavior with 15 operators and 9 action types — show, hide, require, skip fields based on user input. Pure Python, zero dependencies.

Part of the [Form Forge](https://form-forge.codevault.dev) toolkit by CodeVault.

Features

15 comparison operators: equals, not_equals, greater_than, less_than, greater_equal, less_equal, contains, not_contains, starts_with, ends_with, is_empty, is_not_empty, matches (regex), in, not_in
9 action types: show, hide, require, optional, skip, set_value, validate, disable, enable
JSON rule definitions: define all logic in a declarative JSON format
AND/OR logic groups: combine multiple conditions with boolean operators
Field-to-field references: conditions can reference other form field values
Evaluation engine: evaluate rules against live form data and return actions to execute
Python 3.10+ stdlib only — no pip installs required

Quick Start


# Evaluate rules against form data
python src/conditional_logic_engine.py --rules examples/form_rules.json --data '{"country": "US", "age": "25"}'

# Run the built-in demo
python src/conditional_logic_engine.py --demo

CLI Reference

Flag	Description
`--rules FILE`	JSON file containing conditional logic rules
`--data JSON`	Form data as a JSON string to evaluate against
`--demo`	Run a built-in demo showing all operator/action types

Rules JSON Format


{
  "rules": [
    {
      "id": "show-company-field",
      "description": "Show company name when role is Business",
      "logic": "and",
      "conditions": [
        {
          "field": "role",
          "operator": "equals",
          "value": "business"
        }
      ],
      "actions": [
        {
          "type": "show",
          "target": "company_name"
        },
        {
          "type": "require",
          "target": "company_name"
        }
      ]

*... continues with setup instructions, usage examples, and more.*

📄 Code Sample .py preview

src/conditional_logic_engine.py #!/usr/bin/env python3 """ Conditional Logic Engine — Dynamic Form Rules =============================================== Define show/hide rules, skip conditions, dynamic validation, and field dependencies using a declarative JSON-based rule engine. Evaluates conditions at runtime and outputs the active field set. Part of the Form Forge toolkit by DataNest. License: MIT """ from __future__ import annotations import argparse import json import logging import operator import re import sys from dataclasses import dataclass, field from enum import Enum from typing import Any, Callable logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s") logger = logging.getLogger(__name__) # --------------------------------------------------------------------------- # Constants & operator map # --------------------------------------------------------------------------- OPERATOR_MAP: dict[str, Callable[[Any, Any], bool]] = { "equals": operator.eq, "not_equals": operator.ne, "greater_than": operator.gt, "less_than": operator.lt, "greater_equal": operator.ge, "less_equal": operator.le, "contains": lambda a, b: str(b).lower() in str(a).lower(), "not_contains": lambda a, b: str(b).lower() not in str(a).lower(), "starts_with": lambda a, b: str(a).lower().startswith(str(b).lower()), "ends_with": lambda a, b: str(a).lower().endswith(str(b).lower()), "is_empty": lambda a, _: not str(a).strip(), "is_not_empty": lambda a, _: bool(str(a).strip()), "matches": lambda a, b: bool(re.match(str(b), str(a))), "in": lambda a, b: str(a) in (b if isinstance(b, list) else str(b).split(",")), "not_in": lambda a, b: str(a) not in (b if isinstance(b, list) else str(b).split(",")), } class ActionType(Enum): # ... 386 more lines ...

Buy Now — $29 Back to Products