Using webpack-dev-server and HMR

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Using webpack-dev-server and HMR

While developing, instead of using encore dev --watch, you can use the webpack-dev-server:

$ ./node_modules/.bin/encore dev-server

This serves the built assets from a new server at http://localhost:8080 (it does not actually write any files to disk). This means your script and link tags need to change to point to this.

If you've activated the manifest.json versioning you're done: the paths in your templates will automatically point to the dev server.

You can also pass options to the dev-server command: any options that are supported by the normal webpack-dev-server. For example:

$ ./node_modules/.bin/encore dev-server --https --port 9000

This will start a server at https://localhost:9000.


This Webpack server is independent from Symfony's development web server and you need to run both separately.

Using dev-server inside a VM

If you're using dev-server from inside a virtual machine, then you'll need to bind to all IP addresses and allow any host to access the server:

$ ./node_modules/.bin/encore dev-server --host --disable-host-check

You can now access the dev-server using the IP address to your virtual machine on port 8080 - e.g.

Hot Module Replacement HMR

Encore does support HMR, but only in some areas. To activate it, pass the --hot option:

$ ./node_modules/.bin/encore dev-server --hot

HMR currently works for Vue.js, but does not work for styles anywhere at this time.

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.