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Simple Flows

Phlow supports simple flows that don't require a main module or complex module definitions. These flows are perfect for:

  • Data processing and transformation
  • Simple automation tasks
  • Batch processing
  • Testing and prototyping
  • Quick scripts

Basic Example​

The simplest Phlow flow contains only steps:

steps:
  - payload: "Hello, World!"
  - payload: !phs `Result: ${ payload }`

This flow will output: Result: Hello, World!

With Metadata​

You can add metadata to better describe your flow:

name: Simple Greeting
version: 1.0.0
description: A simple greeting flow
author: Your Name
steps:
  - payload:
      message: "Hello, Phlow!"
      timestamp: !phs `new Date().toISOString()`
  - payload: !phs `${ payload.message } - Generated at ${ payload.timestamp }`

Data Processing Example​

Here's a more complex example that processes data:

name: Data Processor
version: 1.0.0
description: Process and transform data
steps:
  - payload:
      users:
        - name: "John"
          age: 25
        - name: "Alice"
          age: 30
        - name: "Bob"
          age: 20
  - payload: !phs `
      payload.users
        .filter(user => user.age >= 25)
        .map(user => \`\${user.name} is \${user.age} years old\`)
        .join(', ')
    `

Using Optional Modules​

You can still use modules without specifying versions:

name: Simple Logging
description: Process data with logging
modules:
  - module: log
    # version omitted - will use 'latest'
    with:
      level: info
steps:
  - payload: "Processing important data"
  - log:
      message: !phs `Starting process: ${ payload }`
  - payload: !phs `Processed: ${ payload }`
  - log:
      message: !phs `Completed process: ${ payload }`

Running Simple Flows​

All simple flows are executed the same way:

# Run the flow
phlow simple-flow.yaml

# With debug logging
PHLOW_LOG=debug phlow simple-flow.yaml

Benefits of Simple Flows​

  • Quick to write: No need to define modules or main entry points
  • Easy to understand: Clear, linear execution
  • Perfect for automation: Ideal for batch processing and simple tasks
  • Backward compatible: Works alongside complex flows
  • Flexible: Can be expanded with modules when needed

When to Use Simple Flows​

Use simple flows when you need:

  • Quick data transformations
  • Simple automation without external dependencies
  • Testing and prototyping
  • Batch processing tasks
  • Educational examples

For more complex scenarios with user input, web servers, or database connections, consider using flows with main modules and explicit module definitions.