Hey hey heyyyyyy! Here’s a quick article on how to have beauty link previews, just like Dev.to does. You're gonna get something like this: Yup, was being literal with the " " 😛 I've built something similar for my new project workby.io, and here's how I did it... like dev.to Almost every guide that I found was using , in fact, uses it. It's pretty popular and efficient, BUT, I don't want to pay $14 bucks for each 1k image 😂🐁 htmlcsstoimage.com dev.to So, I'm going to use : A ruby gem to transform HTML into PDFs, PNGs, or JPEGs using Google Puppeteer and Chromium. Grover If you want to build this with, let's say, Node.js, you can also follow me. Puppeteer is popular and easy to use. We're going to build an HTML view and take a screenshot of it. Long story short: You can create a blank Rails project, or just add additional functionality to your current app. Setup Install Grover gem with bundle add grover And the dependency of Grover, , with: Puppeteer yarn add puppeteer Then create an empty controller where you can respond with different link preview templates: rails g controller og-imager dev_to In the action, let's call Grover and let him do the magic dev_to app/controllers/og_imager_controller.rb class OgImagerController < ApplicationController # GET /og_imager/dev_to # @param {string} title # @param {string} avatar # @param {string} username # @param {string} timestamp # @param {array} logos # @returns image/png def dev_to # Get params and set to variable # TODO: Retrieve your object instead :p @title = params[:title] @avatar = params[:avatar] @username = params[:username] @timestamp = params[:timestamp] @logos = params[:logos] # Grover.new accepts a URL or inline HTML and optional parameters for Puppeteer grover = Grover.new( render_to_string ) # Get a screenshot png = grover.to_png # Render image send_data(png, type: 'image/png', disposition: 'inline') end end Here's our view, just simple HTML/CSS app/views/og_imager/dev_to.html.erb <div class="container"> <div class="card"> <h1 class="title"> <%= @title %> </h1> <div class="details"> <div class="user"> <img src="<%= @avatar %>" class="avatar"> <p class="username"> <%= @username %> - <%= @timestamp %> </p> </div> <div class="logos"> <% @logos.each do |logo| %> <img src="<%= logo %>" class="logo"> <% end %> </div> </div> </div> </div> <style> @import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;500&display=swap'); *{ font-family: 'Roboto', sans-serif; color: #cd685f; } .container{ width: 1128px; height: 600px; display: flex; } .card{ display: flex; justify-content: space-between; flex-direction: column; margin: 2.8rem 4rem 4rem 2.8rem; border: 3px solid #c56b61; border-radius: 25px 25px 0px 0px; box-shadow: 7px 10px 0px 1px #c56b61; padding: 3.8rem 1.8rem 1.8rem 1.8rem; } .title{ margin: 0px; font-weight: 500; font-size: 5rem; line-height: 80px; } .details{ display: flex; justify-content: space-between; } .user{ display: flex; align-items: center; } .avatar{ border: 3px solid #c56b61; width: 50px; height: 50px; border-radius: 50%; margin-right: 10px; } .username{ margin: 0; font-size: 2.5rem; } .logos{ display: flex; justify-content: space-between; } .logo{ width: 60px; height: 60px; margin-left: 20px; transform: rotate(5deg); } </style> And finally, create an initializer to set our Browser viewport (final image size). initializers/grover.rb Grover.configure do |config| config.options = { viewport: { width: 1128, height: 600 }, } end If you have created a blank project, and want to use this as a micro-service, here's a guide on how to deploy this thing to Heroku. Create the app on your Heroku account (I'm assuming you already have the cli installed): heroku create your_app_name Warn Heroku of our JS library (Puppeteer): heroku buildpacks:add heroku/nodejs --index=1 And also help him to setup Puppeteer dependencies 😛: heroku buildpacks:add jontewks/puppeteer --index=2 Tell Grover to run Puppeteer in the "no-sandbox": heroku config:set GROVER_NO_SANDBOX=true To make use of this image on the link preview, you will need . Just simple meta tags that browsers will look for. The Open Graph protocol Meta tags are always on <head> so, app/views/layouts/application.html.erb <%= yield(:head) %> And then ask ERB to fill the previous block with <%= content_for :head do %> <meta property="og:title" content="<%= @article.title %>"> <meta property="og:image" content="<%= article_link_preview(@article) %>"> <meta property="og:image:type" content="image/png" /> <meta property="og:image:width" content="1128"> <meta property="og:image:height" content="600"> <meta name="twitter:card" content="summary_large_image" /> <% end %> at your details view. Like: /articles/:id The thing it's because they are fancier on link previews, you can read more about that twitter:card here The previous method it's a simple helper that generates the URL that we are looking for. article_link_preview app/helpers/articles_helper.rb def article_link_preview article uri = URI.parse('https://your_app_name.herokuapp.com/ogimage') uri.query = URI.encode_www_form( title: article.title, 'images[]': article.tags.collect(&:image), timestamp: article.created_at.to_formatted_s(:short), ... ) uri.to_s end You will get something like this: https://your_app_name.herokuapp.com/og_imager/dev_to?title=Real%20Time%20Notification%20System%20with%20Hotwire,%20in%20Rails%207&avatar=https://dev-to-uploads.s3.amazonaws.com/uploads/user/profile_image/369241/a0111bcb-a046-4398-98cd-f4cf0e2f8d0d.png&username=Matias%20Carpintini&timestamp=13%20April&logos[]=https://img.icons8.com/office/80/000000/ruby-gemstone.png&logos[]=https://practicaldev-herokuapp-com.freetls.fastly.net/assets/devlogo-pwa-512.png Here's the of the whole thing. repo This article was first published here.
