Route Styles

Even though the rendering of a request is dynamic, slash routes resource2/resource1 are meant to mimic a file system, in the sense that when you make the request this is the "location" that you are getting the resource from. This is distinct from things like the format (json) that doesn't affect the location of a resource.

By putting a colon before a string in our route, we can create routes with different variables, or parameters. These parameters are automatically pulled out for us by Express and can be accessed via the request.params object.

const express = require('express')
const app = express()

app.get('/', (request, response) => {
  response.send('hello brian')
});

app.get("/greet/:name/:lastname", (request, response) => {
  response.send("Hello " + request.params.name + " " + request.params.lastname)
});

app.get("/multiply/:x/:y", (request, response) => {
  response.send("The answer is: " + (request.params.x * request.params.y))
});

app.get("/add/:x/:y", (request, response) => {
  response.send("The answer is: " + (parseInt(request.params.x) + parseInt(request.params.y)))
});

// make a search using: localhost:3000?q=pokemon
app.get("/search", (request, response) => {
  response.send("You are searching for: " + request.query.q);
});

In addition to having routes where different portions of the URL are different paramaters, we can use the generic string of the URL in our route logic using the wildcard.

app.get("/add/*", function(req, response) {
  let myParams = req.params[0].split("/")
  const result = myParams.reduce(function(total, num) {
    return total + parseInt(num)
  }, 0);
  response.send("The answer is  " + result)
})

This will give you a URL like http://localhost:3000/add/5/3/3/2/3 and give you an answer.

Query Parameters

Query parameters are used to tell the server that you have a query for the resource you are trying to access. Google search bar URLs are formatted this way: google.com/search?q=bananas

Access Query Parameters:

http://localhost:3000?hello=bye query parameter can be accessed with request.query.hello.

Notice that these are keys and values. hello becomes a key in the query object.

Pairing Exercise:

• Add each of the routes above into your app. Copy each one separately!
• console.log the value of request
• Try changing the :name of the url parameter to see the key change
• Try putting in a query string in addition to the URL parameters