Getting started with Express and the API-first CMS Gentics Mesh

Fast, unopinionated, minimalist. Express is one of the most popular Node.js frameworks out there. It simplifies routing and handling data. This blogpost is part of a series in which we show you how to combine the API-first CMS Gentics Mesh with popular frameworks, such as Express. Our focus is especially on routing and displaying the content with templates..

By Johannes Schüth, on January 23, 2017

Gentics Mesh is the CMS backend for your web applications and apps. It’s API-first so you can choose your favorite languages and frameworks. In this blogpost we are going to provide you with an example for getting started with Gentics Mesh and Express together with the request-promise library as well as the Nunjucks template engine. See how easy it is to swap out technologies and check out the exact same example using the PHP micro-framework Silex together with the Twig template engine.

Getting Ready

Clone the example from the Gentics Mesh Repository on GitHub

git clone https://github.com/gentics/mesh-express-example.git
cd mesh-express-example

Update the node dependencies

npm install

Download Gentics Mesh & start server

# 1. Start Gentics Mesh
java -jar mesh-demo-0.24.xx.jar

# 2. Start the express server
node index.js

The Example

Once set up you should be able to access the running Express server via http://localhost:3000.

The example consists of a small website which lists various vehicles from our demo data. The vehicles are grouped into categories which can be browsed individually. The example also features a breadcrumb navigation and image handling via Gentics Mesh.

gentics njk

Walkthrough

The main logic of our example is located within the index.js file.

The express route handler accepts these requests and processes them. We use the request-promise library to chain the outbound requests.

The Gentics Mesh webroot API makes it very easy to find contents for a corresponding web path. All request paths are passed along to this API in order to load the corresponding node which contains data needed to render the page.

A node can either be a node of type 'category', 'vehicle' or 'vehicleImage'. The schema type information of a node is used to switch between different pages. Loading a category node, for example, will result in the product list template to be rendered. A product node on the other hand will result in a product detail page.

In this example we use the Nunjucks template engine to render the templates.

The templates are structured and utilize template inheritance which is a great way to reuse common parts.

The base.njk template contains the needed includes and definitions for the Twitter Bootstrap template.

By default a breadcrumb navigation is added to each page. We moved the code for the navigation into the navigation.njk file. The Gentics Mesh Navigation Root API is used to load the needed breadcrumb information for the root level.

Hint: In our example only a single level is used and as such the navigation is not changing. In more complex examples the Navigation Root API can also be used to build up multi-level menus which can also be affected by user permissions.

The welcome.njk template just displays some information about the example for requests to the index page. (e.g.http://localhost/).

The productList.njk template is used to display categories. A category can contain multiple products. The template uses a simple loop which iterates over all products in order to display each one. The /api/v1/demo/nodes/:categoryUuid/children endpoint of Gentics Mesh is used here to load all products for a certain category.

Hint: All endpoints which return lists of items can be easily paged. If you plan to display many more items it would be good to also render a paging element.

The productDetail.njk template is used to display all product information on a single page. In this case it is sufficient to pass the resolved Node directly to the template. The needed files can thus be directly used. e.g.: {{ product.fields.description }}.

We hope this example was informative and showed you how easy it is to utilize Express in combination with Gentics Mesh to build a small template-based website.

You can also find it on GitHub: https://github.com/gentics/mesh-express-example

This is the second of a series of articles to show what’s possible with our

API-First CMS Gentics Mesh:

  • Building an API-first Web App with Gentics Mesh and the PHP micro-framework Silex

  • How to build a website with Go and API-first CMS Gentics Mesh

  • Data-driven Apps made easy with Vert.x 3.4.0 and headless CMS Gentics Mesh

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