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https://github.com/reddec/rpc
Golang and JS interaction made simple
https://github.com/reddec/rpc
golang-json-api golang-rpc rpc
Last synced: about 1 month ago
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Golang and JS interaction made simple
- Host: GitHub
- URL: https://github.com/reddec/rpc
- Owner: reddec
- License: mit
- Created: 2022-07-04T13:38:27.000Z (over 2 years ago)
- Default Branch: master
- Last Pushed: 2023-06-19T08:40:09.000Z (over 1 year ago)
- Last Synced: 2024-06-20T00:33:33.217Z (7 months ago)
- Topics: golang-json-api, golang-rpc, rpc
- Language: Go
- Homepage:
- Size: 40 KB
- Stars: 4
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# RPC
[](https://pkg.go.dev/github.com/reddec/rpc)
> Calling Golang backend should be simple.
- no runtime dependencies (for TS generator there is a compile-time dependency)
- 100% test coverage
- simple and efficient
This project was created within one night after my frustration while writing yet another service which basically exposes
DB operations as an HTTP endpoint. The problem is that most of the current approaches offer some kind of framework lock.
Once you write your business logic, you will, basically, have to duplicate the method, which will just accept values
from an HTTP request and proxy it to the business function.
This project allows you to expose almost any kind of structure method as HTTP endpoints.
Supports:
- Any input and output arguments as soon as it is supported by JSON encoder/decoder
- (optionally) First argument can be `context.Context` and it will be wired to `request.Context()`
- Value and/or error output. Example:
- `Foo(...)`
- `Foo(...) error`
- `Foo(...) int64`
- `Foo(...) (int64, error)`
> There are two main packages: [`rpc`](https://pkg.go.dev/github.com/reddec/rpc) and [`jrpc`](https://pkg.go.dev/github.com/reddec/rpc/jrpc).
> The [`rpc`](https://pkg.go.dev/github.com/reddec/rpc) is array-based interaction (function arguments are mapped as-is as array),
> and [`jrpc`](https://pkg.go.dev/github.com/reddec/rpc/jrpc) package is single-payload oriented.
>
> [`rpc`](https://pkg.go.dev/github.com/reddec/rpc) provides less restrictions for Go side, while [`jrpc`](https://pkg.go.dev/github.com/reddec/rpc/jrpc) more friendly for UI and code-generators.
Simplest possible example:
```go
package main
type Service struct{}
func (srv *Service) Sum(a, b int64) int64 {
return a + b
}
func main() {
http.Handle("/api/", http.StripPrefix("/api", rpc.New(&Service{})))
http.ListenAndServe("127.0.0.1:8080", nil)
}
```
In JS side (you can just copy-and-paste)
```js
function RPC(baseURL = "") {
return new Proxy({}, {
get(obj, method) {
method = method.toLowerCase();
if (method in obj) {
return obj[method]
}
const url = baseURL + "/" + encodeURIComponent(method)
const fn = async function () {
const args = Array.prototype.slice.call(arguments);
const res = await fetch(url, {
method: "POST",
body: JSON.stringify(args),
headers: {
"Content-Type": "application/json"
}
})
if (!res.ok) {
const errMessage = await res.text();
throw new Error(errMessage);
}
return await res.json()
}
return obj[method] = fn
}
})
}
```
And use it as:
```js
const api = RPC("/api");
const amount = await api.sum(123, 456)
```
**Alternative** is to use CDN (seriously? for 375 bytes?)
```html
import RPC from "https://cdn.jsdelivr.net/gh/reddec/rpc@1/js/rpc.min.js"
const API = RPC("/api");
const total = await API.sum(123, 456);
```
## Dynamic session
In some cases you may need to prepare session, based on request: find user, authenticate it and so on. For that
use `Builder`.
`Builder` will invoke factory on each request and use returned value as API session object.
For example:
```go
package main
import (
"net/http"
"github.com/reddec/rpc"
)
type userSession struct {
user string
}
func (us *userSession) Greet() string { // this will be an exported method
return "Hello, " + us.user + "!"
}
type server struct{}
func (srv *server) newSession(r *http.Request) (*userSession, error) {
user := r.Header.Get("X-User") // mimic real authorization
return &userSession{
user: user,
}, nil
}
func main() {
var srv server // initialize it!
http.Handle("/api/", http.StripPrefix("/api", rpc.Builder(srv.newSession)))
http.ListenAndServe("127.0.0.1:8080", nil)
}
```
Now, on call `api.greet()`, first will be executed `newSession` and then `userSession.Greet`
### Supporting tools
#### RPC script
Minified version of js/rpc.js supporting script (~400B) embedded to the library and available as global variable
`rpc.JS` and can be exposed as handler by `Script` function:
```go
// ...
http.Handle("/static/js/rpc.min.js", rpc.Script())
```
#### Schema
Package `schema` provides simple way to generate OpenAPI 3.1 schema based on indexed methods from server.
The generated object could be serialized as YAML or JSON and served as handler.
The function `schema.OpenAPI` uses result of `Index` function to generate schema and definition.
```go
var srv Server
index := rpc.Index(&srv)
schema := schema.OpenAPI(index) // customizable by Options
// render as JSON or YAML
```
For the convenience use handler to export schema over HTTP. It will pre-generate and cache schema.
```go
var srv Server
index := rpc.Index(&srv)
// ...
http.Handle("/schema", schema.Handler(index))
```