PHP-and-MySQL/C4/Cookies-Part-1/English-timed
From Script | Spoken-Tutorial
Revision as of 21:43, 4 June 2015 by Sandhya.np14 (Talk | contribs)
Time | Narration |
00:00 | Welcome to this tutorial on php cookies. |
00:04 | Cookies are a very important part when creating special websites where you store information about a user. |
00:11 | The definition of a cookie is - a set of data stored on your computer or the user's computer by the web-server. |
00:18 | This means that when we go to a website, our details are stored and are used when we visit it again, provided we select an option like 'Remember me'. |
00:30 | So that you don't have to keep logging in. |
00:32 | But if you didn't check a button like 'remember me', you will probably be dealing with sessions which close as soon as the user closes the browser. |
00:42 | So, sessions are killed straight away; however, cookies are stored for later use. |
00:50 | So let's begin right away and see how to create a cookie. |
00:53 | You do this by using the setcookie() function. |
00:55 | The function takes 5 parameters but I will use just 3. |
01:00 | The first vital one I will use is the name of the cookie which I will set to 'name'. |
01:05 | The second one is the data that needs to be stored inside this cookie and I'll type "Alex" here. |
01:12 | Now the next one's a bit more tricky. |
01:15 | It's the time in which it expires. |
01:18 | Now this needs to be set in seconds. |
01:21 | And to represent this, I am going to create a variable called '$exp' for expire and this will be equal to the time(). |
01:28 | Let me add some value here. |
01:31 | At the moment I am adding zero. |
01:33 | So, if I echo this out and get rid of this cookie function for now. |
01:39 | I'm just echoing out the time here just to show you what it does. |
01:43 | So, let's refresh. So you can see quite a lot of digits here. |
01:47 | Now this is the unique time-stamp. |
01:50 | And the unique time-stamp is the number of seconds before January the 1st 1970. |
01:56 | So, January the 1st at 12 am ummmm...... in the year 1970. |
02:02 | So you can see it here - I think the number of seconds in here equate to a date in the future. |
02:10 | So for example, at this moment you can see this 88, now 89 and as I keep refreshing, by every second this increases. |
02:20 | So yes, this is quite useful way of adding a specific value here. |
02:28 | Now we need to find out the time in seconds of a day because I want this cookie to expire in a day. |
02:34 | So, I multiply 24 by 60 to get the number of minutes in a day. |
02:39 | And then multiply the answer by 60 to get the number of seconds in a day which is 86,400. |
02:47 | So, if I replace zero with 86400, we have the variable "expire" that now holds the time in the future by a day. |
02:56 | To save time, I am copying this and I will add my 'expire' variable here. |
03:02 | So, this function will set our cookie called 'name' with a value of 'Alex' and it will expire in a day - read in seconds using the 'time' function here. |
03:13 | So let's refresh this page and hey! we can see we have no errors which means it has worked. |
03:19 | Now what I'll do is I'll use block commenting to comment out all of these. |
03:23 | And below this I'll echo out this cookie. |
03:26 | But the reason I have commented this is because you don't need to set a cookie every time the user comes into the page. |
03:33 | If you are using a log-in script and you let the user log into your website, you would need to issue this only once and then the cookie will be stored. |
03:41 | And you could use it within this time that we have set here. |
03:46 | So, what I'll do is I'll set echo and I'll use a dollar sign, sorry, 'underscore cookie'. |
03:52 | Inside here is the name of the cookie so I'll type 'name'. Refresh and you can see 'Alex'. |
03:59 | You can check it out. Even if I close my browser, restart my computer and came back into this page, it will still read Alex because it's been stored into the computer. |
04:11 | Okay, now if I had to set another cookie, let's say, I set another cookie here and this will be 'age' and my age is 19. |
04:24 | And my expiry time I'll just keep as this. |
04:29 | So, let's just put this up here. |
04:31 | We can replace the block commenting with line-comment to keep it neat. |
04:36 | So, for our expiry time, I'll set another cookie in here. |
04:41 | And that will have the same expiry time. Let's see if I can get it right. |
04:46 | Okay, so we'll get rid of this. |
04:48 | We’ve set another cookie with the same expiry time. |
04:51 | Let's refresh. Okay that has been set. |
04:55 | So, what I'll do is comment this out and here I will echo it out. |
05:01 | So, you see we can set more than one cookie in a page. Let's refresh that and we can get 19. |
05:07 | Now we can also set a cookie in a single sentence. |
05:11 | For that, I'll type: echo underscore cookie, "name" and the concatenate "is" and then concatenate my "age". |
05:27 | Therefore we will have a sentence saying "Alex is 19", just from the cookies that we've stored. |
05:34 | And again if I close my browser or restart my computer or come back two hours later, this information will still be there stored on this computer, ready to be used by this page. |
05:44 | So, you can see that they are really very useful to use and really easy to create as well and easy to echo out the user. |
05:53 | Now there's a function we can use called print r() or 'print underscore r'. |
05:58 | And we can echo out 'dollar underscore cookie' here. We can align it a bit later... |
06:05 | Refresh this and you can see we've got an array here and we have a different value. |
06:12 | We have got 'name' and that is equal to "Alex" and we've got an 'age' which is equal to 19. |
06:22 | So, these are cookies and they have been set and these are the values of the cookies. |
06:27 | This can be very useful if you want to echo this out to yourself. |
06:31 | Okay, now there is another function which I will cover in the second part of this tutorial and I'll use an if statement to find out if a cookie is set or not. |
06:41 | And I'll also show you how to unset a cookie. |
06:45 | So join me in part 2 and thanks for watching. This is Evan Varkey, dubbing for the Spoken Tutorial Project. Bye. |