Traffic Types - HTTP Methods

Sorting by Intent

So far we’ve mostly looked at GET requests (sightseeing). But traffic on the Data Superhighway comes in many flavors. Express segregates traffic not just by where it’s going (path), but by what it wants to do (method).

Fig 1: Traffic Sorting Logic.

Here is the standard CRUD breakdown for our interchange:

Method	Action	Driving Analogy
GET	Read	Sightseeing. Just looking.
POST	Create	Delivery Truck. Dropping off new cargo.
PUT	Update (Replace)	Road Construction. Replacing the whole lane.
PATCH	Update (Partial)	Pothole repair. Fixing just one part.
DELETE	Delete	Demolition Crew. Removing the road entirely.

Strict Lane Enforcement

Express is strict. app.get('/things') and app.post('/things') are two completely different roads, even if they share the same asphalt (URL).

// GET /things -> "Show me the things"
app.get('/things', (req, res) => {
  res.send('Here is the list.');
});

// POST /things -> "Take this new thing"
app.post('/things', (req, res) => {
  res.send('New thing received.');
});

// DELETE /things -> "Destroy the things"
app.delete('/things', (req, res) => {
  res.send('Things destroyed.');
});

Solo Warning

If you try to POST to a route that only has a GET handler, Express will give you a 404 Not Found (or 405 Method Not Allowed, if configured). The road exists, but your vehicle type isn’t allowed.

The HTML Form Limitation

Here is a pothole you will hit immediately: Native HTML Forms only support GET and POST.

If you try to set <form method="DELETE">, the browser will ignore you and send a GET request instead (because it defaults to GET if it doesn’t understand the method).

How do we fix this?

1. AJAX / Fetch: JavaScript (on the client) has no such limitation. fetch('/things', { method: 'DELETE' }) works perfectly.
2. Method Override: A middleware technique (often used in classic SSR apps) where we trick the server. We send a POST request but add a query string like ?_method=DELETE. The server sees the note and “pretends” it received a DELETE.

For now, just know that if you are building a pure HTML/Simple Express app without client-side JS, you are mostly stuck in the GET and POST lanes.

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Extra Bits & Bytes

Express HTTP Method Routing - Demo Repo

MDN HTTP Methods

⏭ Dead Ends

What happens when a driver takes a wrong turn and ends up off the map?