README
koa-contrib-pathstringstartswith
a koa middleware, call an user defined middleware if ctx.path path string starts with a give prefix
This is a replacement for koa-mount.
How it works
It accept two params, path prefix, middleware.
If the app's ctx.path starts with path prefix, then
call the middleware.
It do so by a simple string compare. Chart below shows its behavior.
| ctx.path | prefix | call middleware (Y/N) |
|---|---|---|
| / | /api | N |
| /api | /api | Y |
| /api/ | /api | Y |
| /api | /api/ | N |
| /api/ | /api/ | Y |
| /api/v1 | /api/ | Y |
| /api/v1 | /api/v | Y |
| /api/v2 | /api/v2 | Y |
| /api/v2.0 | /api/v2 | Y |
| /api/v21 | /api/v2 | Y |
| /images | /image | Y |
| /images/flower | /image/ | Y |
Usage
If you just want a simple starts with compare, use it.
Otherwise use koa-contrib-pathstartswith instead.
Install via npm or yarn.
# for npm
npm i --save koa-contrib-startswith
# for yarn
yarn add koa-contrib-startswith
Use as a Koa middleware in your app.
// import it
const startsWith = require('koa-contrib-startswith')
// if ctx.path starts with `api/v1`, then call myMiddleware1
app.use(startsWith('/api/v1', myMiddleware1))
// if ctx.path starts with `api/v2`, then call myMiddleware2
app.use(startsWith('/api/v2', myMiddleware2))
Compare to koa-mount
- This koa middleware just call your user-defined middlewares according
the
ctx.path's prefix, it does not re-writectx.path, so the path your middleware get is as is. - This middleware do not mount Koa application.
- It's simple and easy to use.