Gardient/behavioral-patterns
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Update readme

Browse Source
This commit is contained in:
Petrutiu Mihai
2016-07-12 12:24:44 +03:00
parent 301167a30f
commit 97fbc20387
1 changed files with 18 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
README.md
View File

@@ -1,12 +1,14 @@
# BehavioralPatterns BehavioralPatterns
==================
Behavioral Patterns is a .NET core solution that shows some ways to implement the behavioral patterns described by the Gang of Four. Behavioral Patterns is a .NET core solution that shows some ways to implement the behavioral patterns described by the Gang of Four.
Patterns described: Patterns described:
1. Chain of responssibility 1. Chain of responssibility
---------------------------
Implemented in project: ChainOfResponsibility Implemented in project: ChainOfResponsibility
a. Pattern description: ### a. Pattern description:
Decouples sender and receiver (as a sender you don't know who will handle the request/ as a receiver you don't know who the sender is necessary) Decouples sender and receiver (as a sender you don't know who will handle the request/ as a receiver you don't know who the sender is necessary)
Hierarchical in nature Hierarchical in nature
When using the Chain of Responsibility is more effective: ### b.When using the Chain of Responsibility is more effective:
More than one object can handle a command More than one object can handle a command
The handler is not known in advance The handler is not known in advance
The handler should be determined automatically The handler should be determined automatically
@@ -16,16 +18,16 @@ Examples in real life:
-java.util.logging.Logger.#log() -java.util.logging.Logger.#log()
-javax.servlet.Filter#doFilter() -javax.servlet.Filter#doFilter()
-Spring Security Filter Chain -Spring Security Filter Chain
b. Pitfalls: ### c. Pitfalls:
Handling/Handler guarantee - you won't be sure that someone can process the request Handling/Handler guarantee - you won't be sure that someone can process the request
Runtime configuration risk - the order matters/and it might be that the chain is not configured correctly Runtime configuration risk - the order matters/and it might be that the chain is not configured correctly
Chain length/performance issues - in theory you could see a chain that is too big, and it would be a bottleneck in performance Chain length/performance issues - in theory you could see a chain that is too big, and it would be a bottleneck in performance
c. Flavors: ### d. Flavors:
Flavor 1: Execute first that matches the condition and exit -> Get one to process the request, or get the type of object Flavor 1: Execute first that matches the condition and exit -> Get one to process the request, or get the type of object
Flavor 2: Execute all elements of chain until the condition does not match -> Execute all validators until one invalidates the request Flavor 2: Execute all elements of chain until the condition does not match -> Execute all validators until one invalidates the request
Flavor 3: Always execute all handlers Flavor 3: Always execute all handlers
Flavor 4: Instead of each handler, having a successor, you could have each handler have a list of successors, and have it's policy what handlers to execute Flavor 4: Instead of each handler, having a successor, you could have each handler have a list of successors, and have it's policy what handlers to execute
d. Examples described: ### e. Examples described:
Purchase example: Purchase example:
Starting class: PurchaseExample.CheckAuthority Starting class: PurchaseExample.CheckAuthority
Problem that we are trying to solve: Problem that we are trying to solve:
@@ -36,11 +38,20 @@ CheckAuthority allows an employee to request money for approval
if (president can approve it) president will process the request if (president can approve it) president will process the request
2. Command pattern 2. Command pattern
------------------
3. Iterator pattern 3. Iterator pattern
------------------
4. Mediator pattern 4. Mediator pattern
------------------
5. Memento pattern 5. Memento pattern
------------------
6. Observer pattern 6. Observer pattern
------------------
7. State pattern 7. State pattern
------------------
8. Strategy pattern 8. Strategy pattern
------------------
9. Template pattern 9. Template pattern
------------------
10. Visitor pattern 10. Visitor pattern
------------------