template-file

🔀 Replace {{ variables }} in all your files

Use variables to replace template strings in any type of file. This is both a runnable command-line application and JavaScript/TypeScript module.

✨ Some helpful features:

• If you use a JavaScript file as the dataFile argument, whatever object the JS exports is used for replacement.
• If the value of one of the keys is a function, the result of that function is used for replacement.
• Deeply-nested keys can be used for replacements.

Usage

template-file <dataFile> <sourceGlob> <destination>

Arguments

• data - Data file in JSON; used to replace variables in source files
• sourceGlob - Files to process; see glob for syntax
• destination - Destination directory where processed files go

ℹ️ TIP: Remember to place quotes around your arguments (if they contain asterisks, question marks, etc.) to keep your shell from expanding globs before template-file gets to consume them.

Examples

Just handle one file:

template-file data.json template.txt build/

Compile all .abc files in src/ to build/:

template-file stuff.json 'src/**/*.abc' build/

Compile all HTML files in src/ to dist/ using the exported result of a JavaScript module:

template-file retrieveData.js 'src/**/*.html' './dist'

Templates

This uses templates similar to mustache templates, but there are some differences.

Anything between {{ and }} can be replaced with a value. Spacing doesn't matter.

const template = '{{ location.name }} is {{adjective}}.';
const data = {
  location: { name: 'Nashville' },
  adjective: 'cool'
};

render(template, data); //» 'Nashville is cool.'

To render a list of items, you can use {{#example}} and {{/example}}. Empty lists and falsy values aren't rendered:

const template = `
  <h3>Friend List:</h3>
  <ul>
    {{#friends}}
    <li>{{name}}</li>
    {{/friends}}
  </ul>
`;

const data = {
  friends: [{ name: 'Amanda' }, { name: 'Bryson' }, { name: 'Josh' }]
};

render(template, data);
// <h3>Friend List:</h3>
// <ul>
//   <li>Amanda</li>
//   <li>Bryson</li>
//   <li>Josh</li>
// </ul>

If you have an array of primitive values instead of objects, you can use {{ this }} to refer to the current value:

const template = `
### Foods I Like

{{#foods}}
  - {{ this }}
{{/foods}}
`;

const data = {
  foods: ['steak', 'eggs', 'avocado']
};

render(template, data);
// ### Foods I Like
//
// - steak
// - eggs
// - avocado

If a replacement is a function, it is called with no arguments:

const template = `Hello, {{name}}`;

const data = {
  name: () => 'Charles'
};

render(template, data); //» Hello, Charles

API

In addition to the CLI, this module exports several helpers to programmatically render templates.

Example:

import { render, renderFile } from 'template-file';

const data = {
  location: { name: 'Nashville' },
  adjective: 'cool'
};

// Replace variables in string
render('{{ location.name }} is {{ adjective }}.', data); //» 'Nashville is cool.'

// Replace variables in a file (same as above, but from a file)
const string = await renderFile('/path/to/file', data);
console.log(renderedString);

render

Type:

function render(template: string, data: Data): string;

Replaces values from data and returns the rendered string.

import { render } from 'template-file';

const data = {
  location: { name: 'Nashville' },
  adjective: 'cool'
};

render('{{ location.name }} is {{ adjective }}.', data); //» 'Nashville is cool.'

renderFile

Type:

function renderFile(filepath: string, data: Data): Promise<string>;

Reads a file replaces values from data, and returns the rendered string.

import { renderFile } from 'template-file';

// example.html:
// <h1>Welcome back, {{ sites.github.username }}!</h1>

const data = {
  name: 'Blake',
  sites: {
    github: {
      username: 'blakek'
    }
  }
};

renderFile('./example.html', data); //» '<h1>Welcome back, blakek!</h1>'

renderGlob

Type: (note, this may change in a future major version release)

function renderGlob(
  sourceGlob: string,
  data: Data,
  onFileCallback: (filename: string, contents: string) => void
): Promise<void>;

Finds files matching a glob pattern, reads those files, replaces values from data, and calls a function for each file. Note, no string is returned from the function; values are handled through callbacks for each file.

import { renderGlob } from 'template-file';

// ./templates/profile.html:
// <h1>Welcome back, {{ name }}!</h1>

// ./templates/sign-in.html:
// <p>Currently signed in as <em>{{ sites.github.username }}<em>.</p>

const data = {
  name: 'Blake',
  sites: {
    github: {
      username: 'blakek'
    }
  }
};

const files = [];

renderGlob('./templates/*.html', data, (filename, contents) => {
  files.push({ filename, contents });
});

console.log(files);
// [
//   {
//     contents: '<h1>Welcome back, Blake!</h1>',
//     filename: './templates/profile.html'
//   },
//   {
//     contents: '<p>Currently signed in as <em>blakek<em>.</p>',
//     filename: './templates/sign-in.html'
//   }
// ]

renderToFolder

Type:

function renderToFolder(
  sourceGlob: string,
  destination: string,
  data: Data
): Promise<void>;

import { renderToFolder } from 'template-file';

const data = {
  name: 'Blake',
  sites: {
    github: {
      username: 'blakek'
    }
  }
};

renderToFolder('./templates/*.html', './dist/', data);

Finds files matching a glob pattern, reads those files, replaces values from data, and writes a file with the same name to destination.

Upgrading from older versions:

Version 5 renamed some functions to be simpler:

• renderString was renamed render
• renderTemplateFile was renamed renderFile
• renderGlob and renderToFolder were in v4 but were undocumented. The API for renderGlob may change in the future, depending on usage.

Versions < 4 could not lookup properties with a dot in the name. This should be possible since version 4. For example, this was not possible before v4.0.0:

import { render } from 'template-file';

const data = { 'with.dot': 'yep' };

render('Does this work? {{with.dot}}', data);

Install

With either Yarn or npm installed, run one of the following:

Task	with Yarn	with npm
Add this to a project	yarn add template-file	npm install --save template-file
Install this as a development dependency	yarn add --dev template-file	npm install --save-dev template-file
Install this globally	yarn global add template-file	npm install --global template-file

License

MIT