I have the following problem:
- An user can withdraw money from 2 payment systems (but the number of payment systems can change anytime in the future).
- If user has a trusted account on either of these payment systems, money is transfered automatically
- If user enters a new account then he needs to wait until the end of month to be able to transfer money to this account.
Suposse we have payment systems X and Y. There exist all the following information items:
- We can do auto withdraw X (1 – Yes/0 – No)- column 1.
- We can do auto withdraw Y (1 – Yes/0 – No) – column 2.
- We have deficit of X (1 – Yes/0 – No) – column 3.
- We have deficit of Y (1 – Yes/0 – No) – column 4.
- User has trusted account of X (1 – Yes/0 – No) – column 5.
- User has trusted account of Y (1 – Yes/0 – No) – column 6.
- User can auto-withdraw X (1 – Yes/0 – No) – column 7.
- User can auto-withdraw Y (1 – Yes/0 – No) – column 8.
- User can withdraw X in end of month (1 – Yes/0 – No) – column 9.
- User can withdraw Y in end of month (1 – Yes/0 – No) – column 10.
In table bellow I tried to show all use cases:
Column 1; Column 2; Column 3; Column 4; Column 5; Column 6; Column 7; Column 8; Column 9; Column 10
1; 1; 0; 0; 1; 1; 1; 1; 0; 0
1; 1; 1; 0; 1; 1; 0; 1; 1; 0
1; 1; 0; 1; 1; 1; 1; 0; 0; 1
1; 1; 1; 0; 1; 0; 1; 0; 0; 1
1; 1; 0; 1; 0; 1; 0; 1; 1; 0
1; 1; 1; 1; 1; 1; 0; 0; 1; 1
0; 0; 0; 0; 1; 1; 0; 0; 1; 1
Please advise how can I avoid a lot of ifs?
8
How a bout a rules mechanism? Define a class(or a struct or whatever) that defines a rule:
class Rule {
bool weCanDoAutoWithdrawX;
bool weCanDoAutoWithdrawY;
bool WeHaveDeficitOfX;
bool WeHaveDeficitOfY;
...
}
Now, create a list of Rules, and fill it with Rule objects that represent the rules you described in the question. When you want to check a transaction, go over that list and check if it matches the rule. If at least one rule does – approve the transaction.
If you are not familiar with OOP you can store the different sets of conditions as strings of concatenated 1s and 0s (“1100111100″,”1110110110”, etc) stored in a string array. Then you can traverse that array. If at least one string matches the actual values – approve the transaction.
2
As I don’t see any language specified, use ‘switch’.
-Or if using C, you can make a function that handles each account type, then make a list of function pointers.
typedef void (*Account)(uint32_t aParameter);
static const Account[] = { mondoBurger, goodBurger };
-If using C++, JavaScript or any other OOP language, you could make an object that handles each account type.
The bottom line is: You can use modular code.
One “handler” (whether it be a function or an object) for an account.
One “handler” for each action type that can be made.
Thus you just install the handlers in a list and hands the list to the processing function.