Tempra

A lightweight command-line tool for applying Go templates to various data sources.

Overview

Tempra allows you to combine Go templates with data from CSV, JSON, or YAML files to generate text output. It's a simple but powerful tool for generating reports, configuration files, or any text-based output from structured data.

Installation

go install github.com/cedrus-and-thuja/tempra/cmd/tempra@latest

Usage

tempra -template <template_file> -source <data_file>

Required Flags

• -template: Path to the Go template file
• -source: Path to the data source file (CSV, JSON, or YAML)

Data Sources

Tempra supports the following data source formats:

CSV

CSV files are loaded as a list of maps, accessible in the template via .Data. Column headers are automatically title-cased (first character uppercase).

Example CSV:

name,age,city
john,30,new york
jane,25,san francisco

Access in template:

{{range .Data}}
Name: {{.Name}}, Age: {{.Age}}, City: {{.City}}
{{end}}

JSON

JSON files are loaded directly into the template context.

Example JSON:

{
  "users": [
    { "name": "John", "age": 30 },
    { "name": "Jane", "age": 25 }
  ]
}

Access in template:

{{range .users}}
Name: {{.name}}, Age: {{.age}}
{{end}}

YAML

YAML files are loaded directly into the template context.

Example YAML:

users:
  - name: John
    age: 30
  - name: Jane
    age: 25

Access in template:

{{range .users}}
Name: {{.name}}, Age: {{.age}}
{{end}}

Examples

Generate a simple report from CSV

Data file (people.csv):

name,age,occupation
Alice,28,Engineer
Bob,35,Designer
Charlie,42,Manager

Template file (report.template):

# Team Members Report

{{range .Data}}
## {{.Name}}
- Age: {{.Age}}
- Role: {{.Occupation}}
{{end}}

Command:

tempra -template report.template -source people.csv

Output:

# Team Members Report

## Alice
- Age: 28
- Role: Engineer

## Bob
- Age: 35
- Role: Designer

## Charlie
- Age: 42
- Role: Manager

Generate a configuration file from JSON

Data file (config.json):

{
  "app": {
    "name": "MyApp",
    "version": "1.0.0"
  },
  "database": {
    "host": "localhost",
    "port": 5432,
    "username": "admin"
  }
}

Template file (app-config.template):

# Application Configuration

APP_NAME={{.app.name}}
APP_VERSION={{.app.version}}

# Database Settings
DB_HOST={{.database.host}}
DB_PORT={{.database.port}}
DB_USER={{.database.username}}

Command:

tempra -template app-config.template -source config.json

Output:

# Application Configuration

APP_NAME=MyApp
APP_VERSION=1.0.0

# Database Settings
DB_HOST=localhost
DB_PORT=5432
DB_USER=admin

Development

Tempra uses Taskfile for common development tasks.

• task setup: Install development tools
• task lint: Run linters
• task test: Run tests with coverage
• task build: Build the binary
• task run: Run the application

License

[MIT License]