Creating the Display Function

We're now ready to write a custom function that we can use to display the list view 0:00 of an item in both index.php and in catalog.php. 0:04 It's a good idea to name things in a descriptive way 0:09 instead of just making it something short and easy to reference in our code. 0:12 This way when someone else, even our future selves, 0:16 reads this code later, it's easy to understand what's happening. 0:19 Let's get started. 0:23 We'll name this function get_item_html. 0:25 For the parameters, we'll want to pass in the item ID, and 0:27 the interior array for the single item. 0:32 You can include multiple parameters for a function by separating them with a comma. 0:35 In this new function, we'll want to build a string 0:39 with the HTML needed to display the item in our list view. 0:42 We'll then want the function to pass back the HTML as the return value. 0:46 Now, where should we put this function? 0:52 We can't put it in catalog.php because we also need it to be available in index.php. 0:54 We'll need to put this in an include file so that both pages can access it. 1:00 Since this file will contain functions, 1:06 let's create a new include file named functions.php in our inc folder. 1:08 We open up our PHP code and add our new function. 1:14 Get item HTML. 1:21 We include our parameters, ID and item, and open and close our function. 1:23 We already have the code that builds the HTML output for a single item in the list. 1:31 It's over in the catalog.php file right now. 1:37 But we need to move it over here into our function so 1:40 that other files can access it. 1:43 In catalog.php, the code we need is right here. 1:45 So let's copy this and paste it into our function. 1:50 This works, but it's better with functions like this to return the HTML to the main 1:55 code as a piece of text instead of displaying it straight to the screen. 1:59 This gives our main code a little bit more flexibility when calling the functions. 2:03 So instead of echo, let's assign this string to a variable. 2:08 Let's call it output, equals, and the string. 2:13 Let's clean this up a little bit and then return our output. 2:17 Since we moved the code out of catalog.php, 2:27 we need to replace it with the code that calls this function. 2:29 In catalog.php we want to echo 2:32 get item html. 2:38 We want to pass the ID and the item. 2:44 Now we need to modify our foreach loop to get our item ID. 2:49 The ID is the key for the single item we have loaded into our variable. 2:55 So we add ID, equals greater than and then our item. 2:59 Just like we used when we created our array. 3:06 For each item now, as we loop through them one at a time, we pass the item 3:09 information into our function and get back the HTML for that item. 3:12 We then echo out the return value to the screen. 3:17 We haven't included our function page yet, so let's do that now. 3:20 Up at the top we'll include 3:23 inc/functions.php and 3:28 save this file. 3:33 The catalog page hasn't changed much. 3:37 It's working essentially the same way as it was before, but 3:39 we now have the code in a function that we can use on other pages. 3:42 The page that we want to call this function on is index.php. 3:46 I'll copy this whole foreach loop and paste it into our index file. 3:50 We'll replace the list items with 3:58 the call to our function within our foreach loop. 4:03 We need to add the include for 4:11 our data .php and our functions .php. 4:16 Now let's save this page and take a look at it in our browser. 4:22 Now when we refresh the page you can see how all 12 items 4:29 are showing on the homepage just like the catalog page. 4:34 However, on the homepage, we only want to display four random selections. 4:38 Awesome work. 4:45 We just finished creating our first custom function. 4:45 Next, we'll check out a built in php function to choose those four random items 4:48 that we display as suggestions on our home page. 4:53