Category NSObject+MethodCallDependingType

Summary

This category permits to route the call of a method to a specific method depending on a given type.

The goal is to avoid "switch case" or consecutive "if / else if / else" to call a specific method depending on the value of a an attribute or variable.

The category stores the method names of each method of the class which respects a specified "protocol".

Exemple

Depending on a value you have to call different methods with a very similar goal.

@interface MenuViewController : UIViewController
{
    NSString *desiredColor; // Value could be @"Red" or @"Blue"
    ...
}

@end

Without use this category you should do this way:

...
- (void)viewDidLoad
{
    if ([self.desiredColor isEqualToString:@"Red"])
        [self constructRedMenu];
    else if ([self.desiredColor isEqualToString:@"Blue"])
        [self constructBlueMenu];
}
...

With the category:

#import "NSObject+MethodCallDependingType.h"

- (void)viewDidLoad
{
    // Parse the name of each methods wich contains the string @"ColorMenu" and store them
    [test constructMethodsListForRouting:@[@"ColorMenu"] FromClass:[self class]];
    
    [test callRoutedMethod:@"createMenu" withTypeKey:@"ColorMenu" andTypeValue:self.desiredColor andParameters:nil];
}

- (void)createMenuDependingOnColorMenuRed
{
    // do stuff
}

- (void)createMenuDependingOnColorMenuBlue
{
    // do stuff
}

How does it work ?

The method names are stored depending on two types.

• "type key"
• "type value"

A first NSDictionnary property "methodsForRouting" which contains:

• key: "type key"
• value: an intance of the class "MethodsForTypeKey":
  ⇒ A common name of the specific methods (prefix)
  ⇒ An array of the different "type value" which exists for "type key" (suffix)

Why use a "type key" and a "type value" ?

• Optimized by limiting the number of loop iteration to find a desired method.
• Use the same "type value" but for a different "type key".

How the category parses a method name ?

To be parsed a method name must respect the following nomenclature:

1. An identical prefix for all the specifics method:
   ⇒ Ex: createMenu
2. A string which defines the protocol: (Default is "DependingOn" but can be modified with the protocol setter from the category)
   ⇒ Ex: DependingOn
3. A "type key"
   ⇒ Ex: @"ColorMenu"
4. A "type value"
   ⇒ Ex: @"Red"

Result:

- (void)createMenuDependingOnColorMenuRed;

// OR

- (void)createMenuDependingOnColorMenuRed:(Whatever *)params;

How to use it ?

Two ways to init the category:

⇒ First: The category parses the method names

You don't have to parse the method names, the category do this for you by using this method:

/*
 ** @parameter: typeList - Array containing the different types of key that the user need to route his methods.
 ** @parameter: className - The class to get the method names.
 ** Store the class methods name which contains a type from the "typesList" given in paramter
 */
- (void)constructMethodsListForRouting:(NSArray *)typesList FromClass:(Class)className;

⇒ Second: Set a Dictionnary with the method names already parsed

Be careful, you can set your own dictionnary parsed with method names. But if the dictionnary doesn't respect the architecture explained above, the category will no longer work.

- (void)setMethodsForRouting:(NSDictionary *)dictionnary

Protocol

String which permits to identify if a method name needs to be parsed.

By default the string "protocol" value is "DependingOn" but you can set another protocol value by using this setter:

- (void)setProtocol:(NSString *)newProtocol

Licence

The MIT License (MIT)

Copyright (c) 2013 Jean Lebrument

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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