W4

Question 1

app.locals

Answer 1

• allows you to attach local variables to the application, which persist throughout the life of the app

Question 2

app.all()

Answer 2

This method will catch all HTTP requests for all verbs. IE: GET, PUT, POST, DELETE, etc. for a matching path.

Question 3

app.delete()

Answer 3

Routes a HTTP DELETE request for a matching path to a callback function specified.

Question 4

app.engine()

Answer 4

used to map a specific view extension to a template engine. For example if you want to map all html view templates to a specific engine you would register it here.

Question 5

app.get()

Answer 5

Routes a HTTP GET request for a matching path to a callback function specified.

Question 6

app.listen()

Answer 6

• typically called once to setup a port and optionally a host to listen on for requests.
• helps setup a https server and allows it to listen on a specified port. HTTP default port is 80, HTTPS default port is 443.

Question 7

app.post()

Answer 7

Routes a HTTP POST request for a matching path to a callback function specified.

Question 8

app.put()

Answer 8

Routes a HTTP PUT request for a matching path to a callback function specified.

Question 9

app.use()

Answer 9

used to add middleware to your application. Middleware consists of functions (typically placed before the routing methods) that automatically execute either when a specified path is matched or globally before every request.

• very useful when you want to do something with every request like add properties to the request object or check if a user is logged in.

Question 10

req.body

Answer 10

The req.body property contains the data submitted from a request.

• requires that you use a body parsing middleware first which will attach the parameters to req.body. If you post data in your request then this is how you access that data.

Question 11

req.cookies

Answer 11

If you are using a cookie and you use cookie parsing middleware, then the cookie data will be available on the req.cookie object.

Question 12

req.params

Answer 12

The third way of sending data is in the url.

For example, if you want to have a url in the pattern /user/:name where the :name is dynamic; ie: for ‘Bob’ it’s /user/bob and for ‘Mary’ it’s /user/mary.

access each differing username through req.params (ie: request.params.user).

Question 13

req.query

Answer 13

If you send data for a user using a url like /user?user=bob then you can access that username with req.query.user. ‘query’ will be an object with key value pairs matching the key value pairs sent in the query string of the request.

Question 14

req.get

Answer 14

req.get() is useful for checking what the values are of any of the headers sent with the request. If you need to check the ‘content-type’ for example or the ‘referer’ or ‘user-agent’ headers.

Question 15

res.cookie()

Answer 15

allows you to set a cookie on the response with a name = value key pair.

Question 16

res.download()

Answer 16

allows you to send a file back as a response

Question 17

res.end()

Answer 17

end a response immediately and send nothing back. You can also chain .end() off of .status to send a status code and end the response, ie: res.status(400).end();

Question 18

res.get()

Answer 18

use res.get() to lookup any header that is outgoing on the response.

Question 19

res.json()

Answer 19

send back a JSON object with key value pairs of data.

Question 20

res.redirect()

Answer 20

Use this to perform a redirect to another page on your site, go back to the previous page, or redirect to another domain all together.

Question 21

res.send()

Answer 21

You can send a String, an object, an Array, or even a Buffer object back to the client. The send() method will automatically set the Content-Type header for you based on the type of data sent.

Question 22

res.status()

Answer 22

You can use this to send back a specific status code and appropriate response to go with it. status() is chainable before a send() so you can do operations such as: res.status(404).send(“Page Not Found”)

Question 23

What is a route?

Answer 23

a path on your site that can have requests sent to it, and respond from it

Question 24

function to send static files

Answer 24

app.use(express.static(“static”));