PopPage

Introduction

PopPage is a simple command-line utility for applying content to Jinja2 templates to generate files and directories. This project originally started as a static website generator but has since grown into something of a partial cookiecutter clone but it can be used for many purposes including documentation and code generation. The main features of PopPage are:

• Uses Jinja2 templates to generate output.

• Fairly good support for cookiecutter templates.

• Uses YAML to store default key/values for template variables.

• Output can be single files or directories.

• Key/values applied to the templates variables can specified on the command line.

A collection of templates is available here.

Status

The status of this project is beta. This project is suitable for use but there may be incompatibilities in new releases.

Refer to the project changelog for release notes.

Requirements

PopPage requires Python 2.7/3.x.

Installation

PopPage is available on PyPI here and can be installed with pip using the following command: pip install poppage

Usage

PopPage can be run from the command line using poppage. Type poppage --help for usage information. The following subcommands are available:

• check - Check the given INPATH template for variables.

• make - Generates directories and files based on the given INPATH template.

• run - Generates the OUTPATH, executes commands, then deletes OUTPATH.

Some Important Notes

Before showing any examples, keep these notes in mind:

• Template file/directory names can contain template variables (e.g. {{foo}}.txt). The provided key/values will be used for the output file generation unless an explicit OUTPATH is provided.

• The output will be passed to stdout if INPATH is a file (rather than a directory) and INPATH does not contain a template variable and no OUTPATH is specified.

CLI Key/Values

The following is a quick example of using PopPage from the CLI:

• Template file (template.jinja2):

  Hello {{name}}!

• PopPage command:

  poppage make --inpath template.jinja2 --string name world

• Output to stdout:

  Hello world!

YAML Key/Values

Additionally, default key/values can be stored in a YAML file:

• Template file (template.jinja2):

  Hello {{name}}!

• Defaults file (defaults.yaml):

  name: sun

• PopPage command:

  poppage make --inpath template.jinja2 --defaults defaults.yaml

• Output to stdout:

  Hello sun!

Custom YAML Tags

The following custom YAML tags are provided:

• !file - Reads value from a file as a string.

• !yaml - Reads value from file as YAML.

• !opt - Like !yaml but only for populating the __opt__ key.

• !cmd - Reads value from a CLI command output.

• !ask - Prompts the user to input a value.

• !py - Executes Python code.

Check out this example:

• Template file (template.jinja2):

  Hello {{first}} {{last}}!

• Defaults file (defaults.yaml):

  first: !file myfile.txt
  last: !cmd python -c "print('Skywalker')"

• Content of myfile.txt:

  Anakin

• PopPage command:

  poppage make --inpath template.jinja2 --defaults defaults.yaml

• Output to stdout:

  Hello Anakin Skywalker!

Sometimes it might be helpful to process variables in a defaults file. The !py tag can be used in this scenario:

name: !ask &name "Enter a name" (1)
loud: !py ["'{0}'.upper()", *name] (2)

1. The anchor &name is created.

2. A list must be provided to the !py tag. The code is the first element and it can contain standard Python string format variables (e.g. {0}) which will be replaced by the following list elements. Note that an anchor reference can be used as an element!

Option Defaults

Default utility options can be provided in the defaults file under the __opt__ root key.

Check out these examples:

• Basic option defaults:

  __opt__:
      inpath: template.jinja2
      outpath: myfile.txt

• Another options example:

  __opt__:
      inpath: template.jinja2
      outpath: myfile.py
      execute: python myfile.py

• For make commands, multiple inpath and outpath pairs can be specified, the lists are zipped to join the pairs:

  __opt__:
      command: make
      inpath:
        - template1.jinja2
        - template2.jinja2
      outpath:
        - myfile1.py
        - myfile2.py

• The execute option can be a template:

  __opt__:
      inpath: template.jinja2
      execute: python {{outpath}}

• Populate the options using a YAML file:

  __opt__: !opt myopts.yaml

Cookiecutter Compatiblity

PopPage should be compatible with many cookiecutter templates. Using https://github.com/solarnz/cookiecutter-avr as an example, check for the variables in the template:

poppage check --inpath https://github.com/solarnz/cookiecutter-avr
# Found variables:
#   cookiecutter::full_name
#   cookiecutter::repo_name
#   cookiecutter::year

Create a file to store your default values, for example defaults.yaml:

cookiecutter:
    full_name: Henry Jones
    repo_name: LastCrusade
    year: 1989

Run PopPage to generate your files:

poppage make --inpath https://github.com/solarnz/cookiecutter-avr --defaults defaults.yaml --outpath mydest
# This will generate the entire repo to a new directory named mydest.

# Or you can do:
poppage make --inpath https://github.com/solarnz/cookiecutter-avr/tree/master/%7B%7Bcookiecutter.repo_name%7D%7D --defaults defaults.yaml
# This will generate the {{cookiecutter.repo_name}} subdirectory to a new directory based on the given variables, in this case LastCrusade.

Demo Video

A quick demo video is available here on YouTube. This video demos using a single set of requirements information to generate native shell scripts for both Windows and Linux. The templates used in this demo are available on GitHub at the following locations:

• Linux Bash Script

• Microsoft Batch Script

Similar

The following projects are similar and may be worth checking out:

• cookiecutter