content-type-router/readme.md

This is a strictly structured router module designed for internal use only. It assumes all incoming request are either json, text or file/blob via POST method. It doesn't parse flexible parameter in path either.

# Entrance

You need to pass 4 parameters to the `init()` function: request, response, environment object and router map.

- **request** is the same object from http.createServer callback.
- **response** is the same object from http.createServer callback.
- **env** is anything you want to pass to your handler. For example database object.
- **map** is a string/function mapping const. It indicates which handler function should a request with specific path be mapped to.

```javascript
const router = require('mime-router');
const file = require('./local_modules/object/file.js'); // Your handler module
const test = require('./local_modules/object/test.js'); // Your handler module
const map = {
    '/test/server': test.server,
    '/file/upload': file.upload,
};
const env = {
    database: null // Let's say you want to pass a database to the handler too
}
const server = http.createServer(function (req, res) {
    router.init(req, res, env, map);
});
server.listen(process.env.PORT || 8000);
```

# Processing

- If the request contentType is **application/json**, the module will process and transform the body into a json object.
- If the request contentType is **text/plain**, the module will pass the text directly.
- If the request contentType is almost everything else, the module will assume it's a file and form up an object like this:
```json
{
    "buffer": [],
    "contentType": "image/png",
    "category": "image"
}
```

# Handler

A handler function should always have a signature like this:

```javascript
function handler(req, res, env, data) {
    // Deal with the data
}
```

Depends on the **Content-Type** in request header, data will be:

- JSON object if Content-Type is **"application/json"**.
- String if Content-Type is **"text/plain"**.
- JSON object listing in the *Processing* section if Content-Type is anything else.