1 00:00:00,260 --> 00:00:01,300 Hey, welcome back. 2 00:00:01,310 --> 00:00:05,840 In this video, you will learn the concept of context in Django. 3 00:00:05,930 --> 00:00:09,560 Context is a key feature of Django. 4 00:00:09,800 --> 00:00:12,860 So why is context important? 5 00:00:13,010 --> 00:00:17,750 Well, you'll understand that by using an example, as always. 6 00:00:17,750 --> 00:00:21,380 So let's say that currently we have this page. 7 00:00:21,380 --> 00:00:23,870 This is what we built previously, right? 8 00:00:23,870 --> 00:00:30,020 So in this page we want to display the meals, pizza, pasta, etcetera. 9 00:00:30,020 --> 00:00:34,580 And these meals, these data will be stored in the database. 10 00:00:34,580 --> 00:00:38,390 So Python will have access to the database, right? 11 00:00:38,420 --> 00:00:42,320 So for example, in Views.py we have Python code. 12 00:00:42,320 --> 00:00:49,430 So that means we need to get those data from Python to HTML. 13 00:00:49,520 --> 00:00:51,860 So from Python to. 14 00:00:54,290 --> 00:00:56,950 XHTML index.html. 15 00:00:56,960 --> 00:01:00,680 So this here is produced by index.html. 16 00:01:00,710 --> 00:01:04,700 So to get those data we use the context. 17 00:01:06,240 --> 00:01:07,980 So that's a bold theory. 18 00:01:08,010 --> 00:01:10,490 Now, let's implement the context here. 19 00:01:10,500 --> 00:01:12,960 So we're talking about this page, right? 20 00:01:12,990 --> 00:01:17,700 The home page, which is represented by this view. 21 00:01:17,730 --> 00:01:23,260 So now in this view, we create a function, a method. 22 00:01:23,280 --> 00:01:33,450 So this is a method since it's inside a class, A get context data, you have to name this method exactly 23 00:01:33,450 --> 00:01:40,140 like this gets underscore context data because this is basically a predefined method. 24 00:01:40,140 --> 00:01:43,770 It's a method that is part of list view of this class. 25 00:01:43,770 --> 00:01:49,290 So we are overriding this method by reusing that name. 26 00:01:49,980 --> 00:01:55,080 So this has to have a self argument since it's inside the class. 27 00:01:55,080 --> 00:01:59,460 And then inside here we create a context variable. 28 00:01:59,460 --> 00:02:02,160 This is a context I was talking about. 29 00:02:02,190 --> 00:02:13,630 Now this context is a dictionary and this dictionary can contain keys and values, let's say pizza here. 30 00:02:14,510 --> 00:02:15,500 In this example. 31 00:02:15,500 --> 00:02:20,090 It's a dictionary of one key and one value for that key. 32 00:02:20,420 --> 00:02:23,120 And then you return that context. 33 00:02:23,200 --> 00:02:26,220 Then you go to your index.html. 34 00:02:26,270 --> 00:02:28,640 Let's, let's split this to the right. 35 00:02:28,640 --> 00:02:35,990 And somewhere in between the body tags, you want to display that data. 36 00:02:35,990 --> 00:02:48,800 For example, let's write some h three tags and inside this h three tags you write this jinja to syntax, 37 00:02:48,800 --> 00:02:51,680 and in between you write meals. 38 00:02:51,860 --> 00:02:55,310 So this corresponds to the key here. 39 00:02:55,400 --> 00:03:00,320 And then you go to the website, refresh it, make sure you are running the app. 40 00:03:00,320 --> 00:03:09,290 So I'm running the app Currently you can run the app using Python Manage.py run server and so refresh 41 00:03:09,290 --> 00:03:12,320 the page and there we go, we get pizza. 42 00:03:12,890 --> 00:03:22,110 So what I just did here is that I had this string pizza inside Python and I was able to send that string 43 00:03:22,110 --> 00:03:24,000 into the front end here. 44 00:03:24,000 --> 00:03:26,100 So this is just a static string. 45 00:03:26,100 --> 00:03:33,030 But normally we're going to get this data from the database using some more lines of code here. 46 00:03:33,480 --> 00:03:38,280 But for now, let's just create some static strings in here. 47 00:03:38,280 --> 00:03:49,680 So just to demonstrate you that you can send Python values from your python code to your HTML code just 48 00:03:49,680 --> 00:03:50,460 like that. 49 00:03:51,090 --> 00:03:56,430 So the context more technically now we can speak in more technical terms. 50 00:03:56,430 --> 00:04:02,130 The context is a dictionary made of keys and values. 51 00:04:02,340 --> 00:04:07,950 In this example, it has only one key meals and this has this value. 52 00:04:07,980 --> 00:04:09,990 So the context is a dictionary. 53 00:04:09,990 --> 00:04:18,089 And then from your HTML templates you can access the keys of that dictionary as variables. 54 00:04:18,089 --> 00:04:21,060 So you see no quotes around meals. 55 00:04:21,450 --> 00:04:24,720 And then this will get the value of this. 56 00:04:24,720 --> 00:04:26,130 This can also be a list. 57 00:04:26,130 --> 00:04:31,740 So you can say pizza, comma, pasta, right? 58 00:04:31,770 --> 00:04:38,550 If you refresh the page here, you're going to get a list and then I'll show you techniques how to iterate 59 00:04:38,550 --> 00:04:46,850 over that list to to show those items one by one here as bullet points or wherever you like. 60 00:04:46,860 --> 00:04:54,120 And of course, we can put a comma here and maybe like expand the dictionary in the next line and you 61 00:04:54,120 --> 00:04:54,960 can say 62 00:04:56,940 --> 00:05:03,990 ingredients, comma, and then you have a list of other things, things here. 63 00:05:05,100 --> 00:05:11,460 So this here ingredients can also be accessed. 64 00:05:14,290 --> 00:05:17,080 Similarly using the same syntax. 65 00:05:19,740 --> 00:05:20,610 Like that. 66 00:05:21,890 --> 00:05:22,670 Refresh. 67 00:05:22,670 --> 00:05:25,370 And here we have the value of ingredients. 68 00:05:26,650 --> 00:05:31,500 So that's how you send data from your Python code to HTML. 69 00:05:31,540 --> 00:05:39,370 And then next to what's next is that we want to create an admin interface so that we are able to add 70 00:05:39,370 --> 00:05:41,650 some records to our database table. 71 00:05:41,650 --> 00:05:43,510 So meals with their ingredients. 72 00:05:43,510 --> 00:05:49,290 And then we want to display those data here on the web page. 73 00:05:49,300 --> 00:05:51,610 So that's about it for now. 74 00:05:51,640 --> 00:05:53,040 I'll see you in the next videos. 75 00:05:53,050 --> 00:05:53,530 Thanks.