WEBVTT 0 00:09.260 --> 00:15.460 This is such a complicated topic, and that's why it's so important for me to spend more time on it... 1 00:15.620 --> 00:16.070 before we move on. 2 00:16.460 --> 00:23.560 I want to look at this URL Encoding and I want us to look at the example we had by using the "theta" 3 00:23.720 --> 00:24.240 character. 4 00:25.010 --> 00:26.600 Remember what we're doing here... 5 00:26.720 --> 00:29.540 we're looking at what happens when the page's charset 6 00:29.540 --> 00:33.680 does not contain a character that's entered into the form. 7 00:35.290 --> 00:42.460 There's our form. We defined the accept-charset attribute as being ISO-1859-1. And our user 8 00:42.460 --> 00:45.100 typed in a character outside of this range. 9 00:46.150 --> 00:49.420 The user typed in a character of theta. 10 00:49.660 --> 00:53.830 This theta character does not appear in the ISO encoding. 11 00:54.010 --> 01:01.390 So this means trying to encode it with the ISO encoding type will present a significant problem to the 12 01:01.390 --> 01:01.920 browser. 13 01:02.260 --> 01:07.900 And as I discussed previously, each browser, each different browser will handle this problem differently. 14 01:08.320 --> 01:10.270 Chrome will produce the following... 15 01:10.630 --> 01:11.650 GET url. 16 01:12.640 --> 01:18.700 We've seen this. And at first glance you might think this is so odd and weird, but once you understand... 17 01:18.700 --> 01:23.230 how encoding works, you'll know exactly why this URL looks the way it does. 18 01:23.500 --> 01:24.430 So let's jump into it. 19 01:24.430 --> 01:28.510 Let's discuss why this URL looks the way it does before we get into the nitty gritty. 20 01:28.520 --> 01:33.880 The first thing I want you to notice, which is quite straightforward, is that all your form data... 21 01:33.880 --> 01:41.530 is sent to the server after that question mark ? sign in the URL, and every variable you send to the server... 22 01:41.530 --> 01:47.460 will be displayed as a "name=value" pair, separated by an equal sign. 23 01:47.890 --> 01:53.320 OK, so your variables name is to the left of the equal and your variables values to the right of that 24 01:53.320 --> 01:53.850 equals sign. 25 01:54.670 --> 01:56.050 Pretty straightforward, right? 26 01:57.640 --> 02:02.950 Whaaaat 😕! Why do we have this question mark and these equal signs in the URL? 27 02:02.950 --> 02:05.800 Are we going to be talking more about this later... 28 02:06.310 --> 02:13.870 but just as a bit of a spoiler alert, this is what's known as URL encoding that the browser implements. 29 02:14.140 --> 02:20.380 The browser has to make sure that all the characters in that URL are (a) understood universally all of 30 02:20.380 --> 02:25.300 the browsers and servers and (b), that they are safe characters, that they don't conflict with your 31 02:25.300 --> 02:26.310 code, for example. 32 02:26.680 --> 02:32.420 And as we'll discuss a bit later, I'm going to have a dedicated, um, lecture or lectures on URL Encoding... 33 02:32.440 --> 02:35.130 so don't worry yet. For now, 34 02:35.140 --> 02:41.290 remember that URLs can only be sent over the web using the ASCII character set. 35 02:41.590 --> 02:48.910 And since URLs often contain characters that are outside of this ASCII character set, the URL has to... 36 02:48.910 --> 02:51.970 be converted into valid ASCII format. 37 02:52.540 --> 02:53.350 Makes sense, right? 38 02:53.800 --> 03:01.900 So URL encoding just takes unsafe characters and puts a percentage sign first, with two hexadecimal... 39 03:02.170 --> 03:03.550 characters after it. Whew, 40 03:04.240 --> 03:06.040 abut this now poses another problem. 41 03:06.040 --> 03:07.650 What is hexadecimal digits? 42 03:07.960 --> 03:13.480 I don't want to get into detail about that here, but just know as humans, we love decimal, we love... 43 03:13.480 --> 03:19.720 using our 10 fingers 🖐🖐, which means in a decimal system, each character can represent a number from 0 44 03:19.720 --> 03:20.200 to 9. 45 03:20.590 --> 03:22.330 Makes sense to us as humans. 46 03:22.330 --> 03:26.440 At a machine's fundamental level, the machine understands binary. 47 03:26.660 --> 03:29.620 It uses a completely different system, 1s and 0s. 48 03:29.950 --> 03:36.310 And when we are talking hexadecimal, we are using a completely different system. In a hexadecimal system... 49 03:36.340 --> 03:43.480 a single character can represent 0 to 15 unique values. And hexadecimal just very widely used... 50 03:43.990 --> 03:45.340 by computers and programmers. 51 03:45.550 --> 03:46.270 It's just the way it is. 52 03:46.270 --> 03:47.770 It's just has been around for a very long time. 53 03:48.220 --> 03:49.350 Let's jump back into the lecture.