Get Started with Node.js

This tutorial will guide you through writing a JavaScript file to process a template and generate a document locally on your machine using the Docxtemplater library and a Node.js environment.

It's an excellent starting point to explore Docxtemplater and create your first document with tags.

Prerequisites

• Basic familiarity with the command line.

On your computer or server, you will need:

• Node.js. An open-source, cross-platform JavaScript runtime environment that lets you run JavaScript code outside of a browser.
• The Node.js Package Manager (npm) which comes preinstalled when you install nodejs.

Check

You can test that all commands work correctly by opening a terminal and run :

node --version

This should return v20.18.0 or v22.9.0 or any other version number.

Then, run :

npm --version

This should return 10.9.0 or any other version number.

If one of these doesn't return a version, try to reinstall Node.js.

Installation

The first step is to install Docxtemplater and PizZip via npm.

Both libraries are developed by our team.

npm install --save docxtemplater pizzip

This command installs Docxtemplater and PizZip in your Node.js environment.

Usage

First, download the input.docx file and place it in a folder. This file serves as your "template" and includes two tags: {last_name} and {first_name}.

Next, create a new file named your_script_name.js in the same folder as the template. This file will contain the script that generates the document.

Copy the following code into your_script_name.js:

// Load our library that generates the document
const Docxtemplater = require("docxtemplater");
// Load PizZip library to load the docx/pptx/xlsx file in memory
const PizZip = require("pizzip");

// Builtin file system utilities
const fs = require("fs");
const path = require("path");

// Load the docx file as binary content
const content = fs.readFileSync(
    path.resolve(__dirname, "input.docx"),
    "binary"
);

// Unzip the content of the file
const zip = new PizZip(content);

/*
 * Parse the template.
 * This function throws an error if the template is invalid,
 * for example, if the template is "Hello {user" (missing closing tag)
 */
const doc = new Docxtemplater(zip, {
    paragraphLoop: true,
    linebreaks: true,
});

/*
 * Render the document : Replaces :
 * - {first_name} with John
 * - {last_name} with Doe,
 * ...
 */
doc.render({
    first_name: "John",
    last_name: "Doe",
    phone: "+33666666",
    description: "The Acme Product",
});

/*
 * Get the document as a zip (docx are zipped files)
 * and generate it as a Node.js buffer
 */
const buf = doc.getZip().generate({
    type: "nodebuffer",
    /*
     * Compression: DEFLATE adds a compression step.
     * For a 50MB document, expect 500ms additional CPU time.
     */
    compression: "DEFLATE",
});

// Write the Node.js Buffer to a file
fs.writeFileSync(path.resolve(__dirname, "output.docx"), buf);
/*
 * Instead of writing it to a file, you could also
 * let the user download it, store it in a database,
 * on AWS S3, ...
 */

Navigate to the folder containing your script using the command line and run your_script_name.js with Node.js:

node your_script_name.js

After running this command, you will find an output.docx file in the same folder, with the {first_name} tag replaced by "John" and the {last_name} tag replaced by "Doe".

Congratulations!

To go further

View how you can create conditions, loops, or read more about docxtemplater's syntax.

Explore more functionalities of Docxtemplater with our various demos that explore the different functionalities of docxtemplater. These demos showcase how to create more complex templates and scripts.