Using a switch statement to append URL structure - php

Question

So I have the following switch statement inside a method inside my class:
public function getSASURL(string $blobName, string $size = '') : string
{
if ($this->containerName === 'userpictures-resized') {
switch ($size) {
case 'small':
return '_SThumb';
break;
case 'medium':
return '_MThumb';
break;
case 'large':
return '_LThumb';
break;
case 'original':
return '_Original';
break;
case 'big':
return '_Big';
break;
}
return $this->generateSASURL($blobName . $size . '.jpg');
}
return $this->generateSASURL($blobName);
}
Here is what it's doing:
When I call:
$sasURL = $azure->getSASURL('AHahn_com');
I get the following thing back - this works as expected.
https://storageaccount.blob.core.windows.net/userpictures-resized/AHahn_com.jpg?sv=2017-11-09&sr=b&st=2020-10-08T13:04:47Z
Now when I call:
$sasURL = $azure->getSASURL('AHahn_com', 'small');
I get the following back:
'_SThumb'
Instead, this is the result that I want to receive back (with _SThumb after the filename, before the extension):
https://storageaccount.blob.core.windows.net/userpictures-resized/AHahn_com_SThumb.jpg?sv=2017-11-09&sr=b&st=2020-10-08T13:04:47Z
Does anyone know what I might be doing wrong?

Answer 1

Your problem is that you return from the switch statement rather than use the value for each case. You can either overwrite $size inside each case, so for example $size = '_SThumb'; instead of return '_SThumb';, or create another variable which you substitute for $size to your generateSASURL() method.
However, another approach could be to create a map of the sizes and their corresponding value. Then just access the array with $size as a key. To make it case-insensitve, you can do $map[strtolower($size)]. The default value (when no match was found) is the value after the null-coalescing operator ??, which could be anything - here it's $size, but it could be an empty string if that's more applicable.
public function getSASURL(string $blobName, string $size = '') : string
{
if ($this->containerName === 'userpictures-resized') {
$map = [
'size' => '_SThumb',
'medium' => '_SThumb',
'large' => '_MThumb',
'original' => '_Original',
'big' => '_Big',
];
return $this->generateSASURL($blobName . ($map[$size] ?? $size) . '.jpg');
}
return $this->generateSASURL($blobName);
}