WebFund 2015W: Assignment 9
This assignment has 15 points. For each of the following five HTTP GET and POST requests:
- give a transcript of the HTTP request going out and the response returned by the ajax-notes server, as CAPTURED BY YOU using socat as discussed in Tutorial 9 (1 point),
- briefly explain how the browser made this request (did the user type an address in the URL bar or did they interact with a page, and if they interacted with a page how did that page generate that HTTP request) (1 point), and
- briefly explain what code the server ran to generate the response. (1 point)
In other words, you should be giving an HTTP request example and then explaining the browser context that generated the request and the server context that generated the response.
Submit your answers on cuLearn in a text or PDF file by 10 AM on Monday, March 30, 2015. No other formats will be accepted.
- GET /
- GET /javascripts/notes.js
- GET /getNotes
- POST /updateNote
- POST /newNote
Solutions
Note I inserted blank lines between the request and response in the transcripts below. I also deleted the socat request/response metadata that sometimes gets inserted just before the end of the previous request/response (e.g., the timestamp inserted before the closing > of the trailing <html> tag).
GET /
> 2015/04/05 13:06:41.964459 length=406 from=0 to=405
GET / HTTP/1.1\r
Host: localhost:3005\r
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:37.0) Gecko/20100101 Firefox/37.0\r
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r
Accept-Language: en-US,en;q=0.5\r
Accept-Encoding: gzip, deflate\r
DNT: 1\r
Cookie: connect.sid=s%3A7VfppM1sNSPZH2ItZKhGrNFwEYtZ9hqe.j39zaf1VaOxBtKb48jUl%2BrxDauYO3IQSu%2BMaNlQgBz8\r
Connection: keep-alive\r
\r
< 2015/04/05 13:06:41.984748 length=188 from=0 to=187
HTTP/1.1 200 OK\r
X-Powered-By: Express\r
Content-Type: text/html; charset=utf-8\r
Content-Length: 588\r
ETag: W/"24c-32554b76"\r
Date: Sun, 05 Apr 2015 17:06:41 GMT\r
Connection: keep-alive\r
\r
< 2015/04/05 13:06:41.985227 length=587 from=188 to=774
<!DOCTYPE html>
<html>
<head>
<title>COMP 2406 AJAX Notes Demo</title>
<link rel="stylesheet" href="/stylesheets/style.css">
<script src="/javascripts/jquery-1.11.2.js"></script>
</head>
<body>
<h1>COMP 2406 AJAX Notes Demo</h1>
<p>Welcome to COMP 2406 AJAX Notes Demo</p>
<p>Please log in</p>
<div>
<form action="/login" method="post">
<div>
<input type="text" name="username">
<label for="username">Username</label>
</div>
<button type="submit">Login</button>
</form>
</div>
</body>
</html>
GET /javascripts/notes.js
Note that in order to prevent the notes.js response from getting mixed in with the jQuery response (which happened concurrently), I had to change layout.jade to instead load the script from code.jquery.com (so it wouldn't appear in the socat output). Specifically, I replaced the existing jquery loading line with "script(src='//code.jquery.com/jquery-1.11.2.min.js')".
> 2015/04/05 13:25:30.458213 length=445 from=0 to=444
GET /javascripts/notes.js HTTP/1.1\r
Host: localhost:3005\r
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:37.0) Gecko/20100101 Firefox/37.0\r
Accept: */*\r
Accept-Language: en-US,en;q=0.5\r
Accept-Encoding: gzip, deflate\r
DNT: 1\r
Referer: http://localhost:3005/notes\r
Cookie: connect.sid=s%3AInaH5BQtzrhgc1eCqzAq_Xvx5ZDZFm9k.glgLGfIdJ1ZTQv8jQ9GLVwVa3Tn%2BUp3Ws0JiTE6JeuY\r
Connection: keep-alive\r
Pragma: no-cache\r
Cache-Control: no-cache\r
\r
< 2015/04/05 13:25:30.468303 length=3761 from=0 to=3760
HTTP/1.1 200 OK\r
X-Powered-By: Express\r
Accept-Ranges: bytes\r
Date: Sun, 05 Apr 2015 17:25:30 GMT\r
Cache-Control: public, max-age=0\r
Last-Modified: Mon, 09 Mar 2015 01:05:38 GMT\r
ETag: W/"d90-56881568"\r
Content-Type: application/javascript\r
Content-Length: 3472\r
Connection: keep-alive\r
\r
$(function() {
var insertNotesIntoDOM = function(userNotes) {
var i;
$(".notes").remove();
for (i=0; i < userNotes.length; i++) {
console.log("Adding note " + i);
$("#notesList").append('<li class="notes"> <div>' +
userNotes[i].title + ": " +
'<button type="button" class="editButton"' +
'id="edit' + i + '">' + '[edit]</button>' +
'<p>' + userNotes[i].content + '</p>' +
"</li>");
$("#edit" + i).click(userNotes[i], editNote);
}
}
var getAndListNotes = function() {
$.getJSON("/getNotes", insertNotesIntoDOM);
}
var updateNoteOnServer = function(event) {
var theNote = event.data;
theNote.title = $("#noteTitle").val();
theNote.content = $("#noteContent").val();
noteListing();
$.post("/updateNote",
{"id": theNote._id,
"title": theNote.title,
"content": theNote.content},
getAndListNotes);
}
var editNote = function(event) {
var theNote = event.data;
$(".notesArea").replaceWith('<div class="notesArea" ' +
'id="editNoteDiv"></div>');
$("#editNoteDiv").append('<h2>Edit Note</h2>');
$("#editNoteDiv").append('<div><input type="text" ' +
'id="noteTitle"></input></div>');
$("#noteTitle").val(theNote.title);
$("#editNoteDiv").append('<div><textarea cols="40" rows="5" ' +
'id="noteContent" wrap="virtual">' +
'</textarea></div>');
$("#noteContent").val(theNote.content);
$("#editNoteDiv").append('<button type="button" id="updateNote">' +
'Update</button>')
$("#updateNote").click(theNote, updateNoteOnServer);
$("#editNoteDiv").append('<button type="button" id="cancelUpdate">' +
'Cancel</button>')
$("#cancelUpdate").click(noteListing);
}
var editNewNote = function(result) {
var theNote = {"title": "",
"content": ""};
if (result.indexOf("ERROR") == -1) {
theNote._id = result;
editNote({data: theNote}); //faking event object
} else {
// report that we couldn't create a note
noteListing();
}
}
var newNote = function() {
$.post("/newNote", editNewNote);
}
var noteListing = function() {
$(".notesArea").replaceWith('<div class="notesArea" ' +
'id="listNotesDiv">');
$("#listNotesDiv").append('<h2>Notes</h2>');
$("#listNotesDiv").append('<ul id="notesList">' +
'<li class="notes">Loading Notes...</li>' +
'</ul>');
$("#listNotesDiv").append('<button id="newNote" type="button">' +
'New Note</button>');
$("#newNote").click(newNote);
$("#listNotesDiv").append('<button id="refreshNotes" type="button">' +
'Refresh</button>');
$("#refreshNotes").click(getAndListNotes);
getAndListNotes();
}
noteListing();
});