Component Interface (API) design Guide [4]-notification (notifications)

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Notice (Notifications)

The notification is the other half of the trust agreement. My position is that if you use a trust agreement (which you should use in all appropriate places), you will add a notification of the same functionality so that it provides a complete delegation/notification scheme.

In Mgtilemenu, you can find the interface file about the notification: Mgtilemenucontroller

Rule 23: Notification follows delegate method

There is a natural correspondence between the delegate method (the appropriate, not the data source method) and the notification. You can use them anywhere in your code to achieve exactly the same purpose.

If you have a delegate about the occurrence of an event, you should usually also provide a notification of the same purpose. Even if the delegate method is removed, the user can still use the notification to achieve the corresponding function.

The parameters of the delegate method should match the ' UserInfo (notification added) ' content of the notification, a significant difference between the notification and the direct pass parameter in the delegate, which usually requires loading the information into the dictionary (nsdictionary).

Delegate method:

- (void)Tilemenuwilldisplay:(Mgtilemenucontroller *)Tilemenu;
- (void)Tilemenudiddisplay:(Mgtilemenucontroller *)Tilemenu;

The corresponding notification:

extern NSString * mgtilemenuwilldisplaynotification ;
extern NSString * mgtilemenudiddisplaynotification ;

Rule 24: Don't skimp ' userInfo (notice added value) '

Enough information to notify the object. Keep in mind that the notification sink may (almost always) not hold a reference to a delegate or data source component.

Ask yourself what is useful and provide the appropriate information. At the very least, you must ensure that the parameters provided to the corresponding delegate method are included in the UserInfo object.

Delegate method:

- (void)Tilemenu:(Mgtilemenucontroller *)TilemenuWillswitchtopage:(Nsinteger)pagenumber;
- (void)Tilemenu:(Mgtilemenucontroller *)TilemenuDidswitchtopage:(Nsinteger)pagenumber;

The corresponding notification:

// Notice UserInfo contains a key "Mgpagenumber"
#defineMGPageNumberKey @ "Mgpagenumber"
extern NSString * mgtilemenuwillswitchtopagenotification ;
extern NSString * mgtilemenudidswitchtopagenotification ;

Rule 25: Test the hell

Finally, everything has been known to everyone. Specialization in Software engineering 101th: Make sure it does work.

Whether to use formal TDD (test-driven development) depends on you, but the test itself is impossible to do comprehensively. Each of the thousands of combinations of delegate methods, each notification, and each custom point may have problems.

In the event of a defect, you should first find and fix them. If you are in a hurry, you can cut the function. You are bound to be troubled by the problem of bug-free online.

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Component Interface (API) design Guide [4]-notification (notifications)