Phlow Structure

Phlow is a modular runtime for building backends, automations, and orchestrations using YAML to define flows. Each flow is descriptive and structured into modules, steps, and scripts.

This document covers:

• Main structure (main.yaml)
• Modules inclusion (modules.yaml)
• Dynamic scripts (.phs)
• Special commands (!include, !phs, !import)

Example: Student Flow

To better understand the concepts, refer to the Student Flow example. This example demonstrates how to implement a flow that evaluates whether someone is a student based on their age and other parameters.

main: cli
name: Are you a student?
version: 1.0.0
description: Check if you are a student.
author: Your Name
modules: !include modules.yaml
steps:
  - assert: !phs main.force
    then:
      return: !phs `${main.name} is a student, but the age is not valid`
    else:
      - assert: !phs main.age < 18 && main.age > 3
        then:
          return: !phs `${main.name} is a student`
      - assert: !import scripts/condition.phs
        then:
          return: !phs `${main.name} is not a student`
        then:
          return: !phs `${main.name} is not a student`
      - assert: !phs main.age <= 3
        then:
          return: !phs `${main.name} is a baby`  
      - return: !import scripts/output.phs

Flow Logic Overview

The "Are you a student?" flow operates as follows:

1. Captures CLI arguments: name, age, force.
2. If force is true, returns a message indicating the user is a student.
3. Otherwise:
   • If age is 18 or older, returns a message indicating the user is a student.
   • If age is less than 3, indicates the person is a baby.
   • Otherwise, returns an invalid age message.

Structure Visualization

main.yaml
 ├── Header (main, name, version, etc.)
 ├── modules: !include modules.yaml
 └── steps: conditional execution flow

modules.yaml
 └── CLI arguments definition

scripts/
 ├── condition.phs (age validation)
 └── output.phs (error message)