php best practice for validating setter when overloading class properties

Question

Hi,

I have a class that uses the __set magic method. One of the properties for the class can only be set with a certain range of string values, the best example I can think of is the mysql datatype ENUM('value_one','value_two','value_three').

Would I place conditional statements within the __set method to distinguish between which property is being set and whether the value is valid for that property?

Are large switch statements inside a __set method considered sloppy practice, is their a better way of producing the desired results?

Thanks, Ben

Answer 1

The __set function could check for the existance of a method named similar to presetVariableName, which is called and passed the new value as a parameter.

That function could then perform the validation logic, and return true or false as to whether it's valid or not.

Answer 2

Would I place conditional statements within the __set method to distinguish between which property is being set and whether the value is valid for that property?

Yes to the first part, no to the second.

Are large switch statements inside a __set method considered sloppy practice, is their a better way of producing the desired results?

Your __set method should determine which variable is trying to be set and then pass off the rest of the functionality to a private setter setParticularVar. setParticularVar will then contain the logic specific to validating that variable and can throw an exception if an invalid value is passed.

Alternatively, you could make the private setter public instead, allowing two ways to set the variable but this is not as desirable as two ways to set a value is not as clean a design.