The problem

We’re trying to build the booking aspect of the program. We need to be able to book free rooms during free periods based on the timetable. How can we accomplish this?

The solution

Let’s take a step-by-step approach to what we’re trying to do. Pen and paper will be much better to understand this, but here’s a recap:

• We need to look for free times in the user’s schedule:
  • To do this, we can query for the schedule of the user and remove the times when the user is already somewhere else.
• We need to look for free slots in the room’s schedule:
  • A good way to do this is to query for the schedule of the room and remove the times when the room is not available.
• We need to combine these two pieces of information to create a list of available times to book the room.
• After all of this is done, we need to display this information to let the user choose their preferred time.
• The user will send a query to the backend with the required data.
• We take this data and save it into our database to show that the room has been booked.

Some tips to improve the code

I have noticed some stuff while going through the code, so I’ll leave this here if you want to make some small improvements!

• Errors

  • The file “footer.php” is missing in the “includes” folder. This throws an error at the bottom of the page when launching the program with a local server;

  • The function “mysqli_error” expects a connection parameter. It doesn’t break the code, but the correct usage would be something like this ⬇️

    include('../dist/includes/dbcon.php');
    $id = $_REQUEST['id'];
    
    mysqli_query($con,"update settings set status='active' where settings_id='$id'")or die(mysqli_error($con));
    

• Code styling

  • Pay attention to indentation (it’s a way to organise the code to make it more readable). Try to re organise your code a bit without changing the functionality, it will be much easier to work with! Here’s an example with the file “activate.php” ⬇️

    <?php session_start();
    if(empty($_SESSION['id'])):
    header('Location:../index.php');
    endif;
    
    include('../dist/includes/dbcon.php');
    	$id = $_REQUEST['id'];
    	
    	mysqli_query($con,"update settings set status='active' where settings_id='$id'")or die(mysqli_error($con));
    	
    	mysqli_query($con,"update settings set status='inactive' where settings_id<>'$id'")or die(mysqli_error($con));
    		echo "<script type='text/javascript'>alert('Successfully update settings!');</script>";
    		echo "<script>document.location='settings.php'</script>";  
    	
    		$_SESSION['settings']=$id;
    
    		$query2=mysqli_query($con,"select term from settings where settings_id='$id'")or die(mysqli_error($con));
    			$row2=mysqli_fetch_array($query2);
    				$_SESSION['term']=$row2['term'];
    
    	
    ?>
    

    <?php
    session_start();
    
    if(empty($_SESSION['id'])):
    	header('Location:../index.php');
    endif;
    
    include('../dist/includes/dbcon.php');
    $id = $_REQUEST['id'];
    	
    mysqli_query($con,"update settings set status='active' where settings_id='$id'") or die(mysqli_error($con));
    	
    mysqli_query($con,"update settings set status='inactive' where settings_id<>'$id'") or die(mysqli_error($con));
    echo "<script type='text/javascript'>alert('Successfully update settings!');</script>";
    echo "<script>document.location='settings.php'</script>";  
    	
    $_SESSION['settings']=$id;
    
    $query2=mysqli_query($con,"select term from settings where settings_id='$id'") or die(mysqli_error($con));
    $row2=mysqli_fetch_array($query2);
    $_SESSION['term']=$row2['term'];
    ?>
    

  • There are two different schools of thought about writing SQL statements, but I think this is the one that works best for clean SQL code ⬇️

    update settings set status='active' where settings_id='$id'
    

    UPDATE settings SET status='active' WHERE settings_id='$id'
    

Code editor suggestions

If you’re free to choose your code editor, I’ll leave here some suggestions for code editors that you can check out. They’re all free and really help with productivity.

• Visual Studio Code Easy for beginners, has a clean interface and lots of extensions to support every need. Website: https://code.visualstudio.com/.
• Atom It’s probably easier for beginners, but has less features compared to Visual Studio Code. Website: https://atom.io/.
• Sublime Text Very easy for beginners, but like Atom it doesn’t have all the features that Visual Studio Code has. Website: https://www.sublimetext.com/.