hof

README

hof - the high code framework

The hof tool tries to remove redundent development activities by using high level designs, code generation, and diff3 while letting you write custom code directly in the output. ( low-code for developers )

• Users write Single Source of Truth (SSoT) design for data models and the application generators
• hof reads the SSoT, processes it through the code generators, and outputs directories and files
• Users can write custom code in the output, change their designs, and regenerate code in any order
• hof can be customized and extended by only editing text files and not hof source code.
• Use your own tools, technologies, and practices, hof does not make any choices for you
• hof is powered by Cue (https://cuelang.org & https://cuetorials.com)

Install

You will have to download hof the first time. After that hof will prompt you to update and install new releases as they become available.

# Install (Linux, Mac, Windows)
curl -LO https://github.com/hofstadter-io/hof/releases/download/v0.5.15/hof_0.5.15_$(uname)_$(uname -m)
mv hof_0.5.15_$(uname)_$(uname -m) /usr/local/bin/hof

# Shell Completions (bash, zsh, fish, power-shell)
echo ". <(hof completion bash)" >> $HOME/.profile
source $HOME/.profile

# Show the help text
hof --help

You can always find the latest version from the releases page or use hof to install a specific version of itself with hof update --version vX.Y.Z.

Documentation

Please see https://docs.hofstadter.io to learn more.

Join us on Slack! https://hofstadter-io.slack.com (invite link)

Example

There are currently hof modules for:

• hofmod-cli - CLI infrastructure based on the Golang Cobra library.
• hofmod-server - API server based on the Golang Echo library.

You can see them used in:

• hof uses hofmod-cli
• saas uses hofmod-server

The following is a single file example:

package gen

import (
	// import hof's schemas for our generator
	"github.com/hofstadter-io/hof/schema"
)

// A schema for our generator's input
#Input: {
	name: string
	todos: [...{
		name: string
		effort: int
		complete: bool
	}]
}
// create a generator
#Gen: schema.#HofGenerator & {
	// We often have some input values for the user to provide.
	// Use a Cue definition to enforce a schema
	Input: #Input

	// Required filed for generator definitions, details can be found in the hof docs
	PackageName: "dummy"

	// Required field for a generator to work, the list of files to generate
	Out: [...schema.#HofGeneratorFile] & [
		todo,
		done,
		debug,
	]

	// In is supplied as the root data object to every template
	// pass user inputs to the tempaltes here, possibly modified, enhanced, or transformed
	In: {
		INPUT: Input
		Completed: _C
		Incomplete: _I
	}

	// calculate some internal data from the input
	_C: [ for t in Input.todos if t.complete == true { t } ]
	_I: [ for t in Input.todos if t.complete == false { t } ]

	// the template files
	todo: {
		Template: """
		Hello {{ .INPUT.name }}.

		The items still on your todo list:

		{{ range $T := .Incomplete -}}
		{{ printf "%-4s%v" $T.name $T.effort }}
		{{ end }}
		"""
		// The output filename, using string interpolation
		Filepath: "\(Input.name)-todo.txt"
	}
	done: {
		Template: """
		Here's what you have finished {{ .INPUT.name }}. Good job!

		{{ range $T := .Completed -}}
		{{ $T.name }}
		{{ end }}
		"""
		Filepath: "\(Input.name)-done.txt"
	}

	// useful helper
	debug: {
		Template: """
		{{ yaml . }}
		"""
		Filepath: "debug.yaml"
	}
}

// Add the @gen(<name>,<name>,...) to denote usage of a generator
Gen: _ @gen(todos)
// Construct the generator
Gen: #Gen & {
	Input: {
		// from first.cue
		name: gen.data.name
		todos: gen.data.tasks
	}
}