trjhtr

I am building a simple calendar with recurring events.

CalendarEvent.php

id
start_date

CalendarRecurringPattern.php

parent_id
pattern_type // daily, weekly, monthly, yearly ...

Using pattern_type i build each following occurrence starting from start_date, using a recursive function and Carbon::class. What bugs me is the function getNextOccurrence(), I'd like to refactor the if/else block because it's not very clean. Here it is:

use CarbonCarbon;
....

public function getNextOccurrence(Carbon $startDate) 

 $pattern_type = $this->getPatternType() // daily, weekly...

 if ($pattern_type == 'daily') 
 $startDate->addDay();
 else if ($pattern_type == 'weekly') 
 $startDate->addWeek();
 else if ($pattern_type == 'monthly') 
 $startDate->addMonth();
 else if ($pattern_type == 'yearly') 
 $startDate->addYear();
 

Thanks!

I don't personally see a problem with the way its currently structured as there aren't that many options, but you could do it a couple of other ways;

Option 1

Array function name mapping (hacky name I just came up with), you could do the following;

$functionMap = [
 "daily" => "addDay",
 "weekly" => "addWeek",
 "monthly" => "addMonth",
 "yearly" => "addYear"
];

if(!isset($functionMap[$pattern_type]))
 throw new Exception("Can't find patern type $pattern_type", 1);


$startDate->$functionMap[$pattern_type]();

This might be seen as a sin by the PHP community but it works none the less

Option 2

You could use a switch which probably isn't a sin by the community.

switch ($pattern_type) 
 case "daily":
 // Do the daily task
 break;
 case "weekly":
 // Do the weekly task
 break;
 case "monthly":
 // Do the monthly task
 break;
 case "yearly":
 // Do the yearly task
 break;
 default: 
 throw new Exception("Can't find pattern type $pattern_type", 1);

Conclusion

I would add some exception / error that can be picked up if a non matched pattern_type is passed.

I would also convert the "magic strings" E.G "daily" to constants in case you need to re-use, change or update them in the future!

In terms of line count;

• your way 10 lines of code


• option 1 11 lines of code


• option 2 15 lines of code

The switch & if statements may have some advantages when doing code analysis aswel where the expected required input values can be picked up.