Single Page Apps for GitHub Pages

Version 2.0 has an improved redirect query for better SEO performance. The redirect query is what search engines index as the url, which has no negative side effects other than that it is what the user sees as the url on the search results page. The updated query is much more readable by humans so the user has a better semantic understanding of where the search result links to.

Live example

This is a lightweight solution for deploying single page apps with GitHub Pages. You can easily deploy a React single page app with React Router browserHistory, like the one in the live example, or a single page app built with any frontend library or framework.

Why it's necessary

GitHub Pages doesn't natively support single page apps. When there is a fresh page load for a url like example.tld/foo, where /foo is a frontend route, the GitHub Pages server returns 404 because it knows nothing of /foo.

How it works

When the GitHub Pages server gets a request for a path defined with frontend routes, e.g. example.tld/foo, it returns a custom 404.html page. The custom 404.html page contains a script that takes the current url and converts the path and query string into just a query string, and then redirects the browser to the new url with only a query string and hash fragment. For example, example.tld/one/two?a=b&c=d#qwe, becomes example.tld/?p=/one/two&q=a=b~and~c=d#qwe.

The GitHub Pages server receives the new request, e.g. example.tld?p=/..., ignores the query string and hash fragment and returns the index.html file, which has a script that checks for a redirect in the query string before the single page app is loaded. If a redirect is present it is converted back into the correct url and added to the browser's history with window.history.replaceState(...), but the browser won't attempt to load the new url. When the single page app is loaded further down in the index.html file, the correct url will be waiting in the browser's history for the single page app to route accordingly. (Note that these redirects are only needed with fresh page loads, and not when navigating within the single page app once it's loaded).

A quick SEO note - while it's never good to have a 404 response, it appears based on Search Engine Land's testing that Google's crawler will treat the JavaScript window.location redirect in the 404.html file the same as a 301 redirect for its indexing. From my testing I can confirm that Google will index all pages without issue, the only caveat is that the redirect query is what Google indexes as the url. For example, the url example.tld/about will get indexed as example.tld/?p=/about. When the user clicks on the search result, the url will change back to example.tld/about once the site loads.

Usage instructions

For general information on using GitHub Pages please see GitHub Pages Basics, note that pages can be User, Organization or Project Pages

Basic instructions - there are two things you need from this repo for your single page app to run on GitHub Pages

Copy over the 404.html file to your repo as is - Note that you must use a custom domain if you are setting up a Project Pages site in order for GitHub Pages to serve the custom 404 page (if you are creating a User or Organization Pages site, then using a custom domain is optional)
Copy the redirect script in the index.html file and add it to your index.html file - Note that the redirect script must be placed before your single page app script in your index.html file

Detailed instructions - using this repo as a boilerplate for a React single page app hosted with GitHub Pages

Clone this repo ($ git clone https://github.com/rafrex/spa-github-pages.git)
Delete the .git directory (cd into the spa-github-pages directory and run $ rm -rf .git)
Instantiate the repository - If you're using this boilerplate as a new repository
- $ git init in the spa-github-pages directory, and then $ git add . and $ git commit -m "Add SPA for GitHub Pages boilerplate" to initialize a fresh repository
- If this will be a Project Pages site, then change the branch name from master to gh-pages ($ git branch -m gh-pages), if this will be a User or Organization Pages site, then leave the branch name as master
- Create an empty repo on GitHub.com (don't add a readme, gitignore or license), and add it as a remote to the local repo ($ git remote add origin <your-new-github-repo-url>)
- Feel free to rename the local spa-github-pages directory to anything you want (e.g. your-project-name) - If you're adding this boilerplate as the gh-pages branch of an existing repository
- Create and checkout a new orphaned branch named gh-pages for your existing repo ($ git checkout --orphan gh-pages), note that the gh-pages branch won't appear in the list of branches until you make your first commit
- Delete all of the files and directories (except the .git directory) from the directory of your existing repo ($ git rm -rf .)
- Copy all of the files and directories (including hidden dot files) from the cloned spa-github-pages directory into your project's now empty directory ($ mv path/to/spa-github-pages/{.[!.],}* path/to/your-projects-directory)
- $ git add . and $ git commit -m "Add SPA for GitHub Pages boilerplate" to instantiate the gh-pages branch
Set up your custom domain - see GitHub Pages instructions for setting up a custom domain - Note that you must use a custom domain if you are setting up a Project Pages site in order for GitHub Pages to serve the custom 404 page, however, if you are creating a User or Organization Pages site, then using a custom domain is optional (if you don't use a custom domain delete the CNAME file) - Update the CNAME file with your custom domain, don't include http://, but do include a subdomain if desired, e.g. www or your-subdomain - Update your CNAME and/or A record with your DNS provider - Run $ dig your-subdomain.your-domain.tld to make sure it's set up properly with your DNS (don't include http://)
Run $ npm install to install React and other dependencies, and then run $ webpack to update the build
$ git add . and $ git commit -m "Update boilerplate for use with my domain" and then push to GitHub ($ git push origin gh-pages for Project Pages or $ git push origin master for User or Organization Pages) - the example site should now be live on your domain
Creating your own site - Write your own React components, create your own routes, and add your own style! - Change the title in index.html and the title in 404.html to your site's title - Remove the favicon links from the header of index.html - Remove the Google analytics script from the header of index.html (the analytics function is wrapped in an if statement so that it will only run on the example site's domain (http://spa-github-pages.rafrex.com), but you don't need it, so remove it or replace it with your own analytics) - Change the readme, license and package.json as you see fit - For testing changes locally see development environment info below - To publish your changes to GitHub Pages run $ webpack -p for production to update the build, then $ git commit and $ git push to make your changes live
- Note that $ webpack -p is overloaded in the webpack config to strip out dead code not needed in production (e.g. PropTypes validation, comments, etc)

Development environment

I have included my preferred development environment for testing changes locally, which will auto refresh the browser any time changes are made, and can be accessed by running $ npm start (details below). Or you can use your own setup by running $ webpack and serving the index.html file and the 404.html file for 404s.

$ npm start runs the start script in package.json, which runs both of the following commands simultaneously:
- $ webpack -d --watch
  - -d is for development mode with source maps
  - --watch will automatically run webpack -d whenever the files change
- $ live-server --entry-file=404.html
  - live-server does live reloading of all assets - bundle.js, app.css, etc - the --entry-file=404.html will serve 404.html when the requested file can't be found so it mimics how GitHub Pages works (normally I would set --entry-file=index.html which is basically how servers that support single page apps work - and what I wish GitHub Pages would do)

Miscellaneous

The .nojekyll file in this repo turns off Jekyll for GitHub Pages
Need form submission on your static site? Use Formspree
One of the awesome things about the GitHub Pages CDN is that all files are automatically compressed with gzip, so no need to worry about compressing your JavaScript, HTML or CSS files for production