In browser Go compiler

This package provides a way to run Go code in the browser without needing a server, using GopherJS.

heavily inspired by Gopherjs Playground

Features

• Compile Go Code: Transpile Go code into JavaScript that can be run in the browser.
• Non-blocking Compilation: Utilize callback functions to handle the compiled code or any errors.
• Precompiled Package Support: Downloads and caches precompiled package archives from a specified URL.
• Exception Handling: Catches exceptions thrown during execution and returns them as errors.

Usage

Including the Gopherjs Compiler

<script src="https://cdn.jsdelivr.net/gh/naorzr/[email protected]/main.js"></script>

Compiling Go Code

You can then use the global __GOPHERJS__ object to compile Go code:

__GOPHERJS__.Compile(`
package main

import "fmt"

func main() {
  fmt.Println("Hello, playground")
}
`, function(result, err) {
  if (err) {
    console.error("Compilation error:", err);
    return;
  }

  // Handle the compiled code (result)
});

Running Compiled Code

The compile code is a string of JavaScript code that can be executed in the browser.

You can use eval, new Function, or any other method to execute the code:

conviniently, the __GOPHERJS__ object exposes a Run method that can be used to run the compiled code:

__GOPHERJS__.Run(compiledCode);

Importing Precompiled Packages

The logic includes the ability to download and cache precompiled package archives.
By default, the URL is set to "https://cdn.jsdelivr.net/gh/naorzr/[email protected]/playground/pkg/".
Make sure the version tag matches the version used in your go.mod file

How Does It Work

Gopherjs is a library written in Go that enables compiling Go code into a single executable javascript file. currently, the Gopherjs compiler is available only on the server side, since it's written in Go, but using the Gopherjs compiler, we can compile the compiler to a javascript file, that will enable us to use it on the client side.

the main.go file describes the process of using the compiler and exposing globals, and then that file is compiled to main.js using the Gopherjs compiler.

Development

To update the entire playground environment, just run https://github.com/naorzr/gopherjs-runtime. It will install your local version of GopherJS compiler, build the playground, make a temporary copy of Go to /tmp/gopherjsplayground_goroot, rebuild and copy the standard library into the pkg directory.

Working on the playground application itself is made easier by using the gopherjs serve command to rebuild and serve the sample playground every time you refresh the browser.

gopherjs serve

Then open http://localhost:8080/.

Upgrading GopherJS release

Step 1: Update the version in go.mod to the latest version.

VERSION="$(go list -m -versions -f "{{ range .Versions }}{{ println . }}{{ end }}" github.com/gopherjs/gopherjs | tail -n 1)"
echo "$VERSION"
go get -v "github.com/gopherjs/gopherjs@$VERSION"
go mod tidy

Step 2: Update the jsdelivr URL in main.go to the corresponding version.

Step 3: rebuild main.go to main.js using the GopherJS compiler.

Contributions

Please open an issue on GitHub for support or contributions.

License

MIT License (c)