Combining Conditions

The Purpose of Combining Conditions

A condition by itself is a useful tool for sifting data, but what if we want data that satisfy multiple criteria? Combined conditions are helpful in creating complex searches.

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Conditions That Checks if Multiple Conditions are All Satisfied

Declaration

+(instancetype) conditionsAreMet:(NSArray<StackBaseCondition *> *)conditions;

Example

//get the first 3 rows where columns 'Name' and 'Memo' contain matches for the phrase 'Matt' and also where column 'id' is greater than 10 
StackBaseCondition *columnsMatchPhrase = [StackBaseCondition columnsWithNames:@[@"Name", @"Memo"] matchPhrase:@"Sean"];
    
StackBaseCondition *idIsBigEnough = [StackBaseCondition columnWithName:@"id" isGreaterThan:@10];

[weakSelf.table getFirst:3 
rowsWhere:[StackBaseCondition conditionsAreMet:@[columnsMatchPhrase, idIsBigEnough]]
completionBlock:^(BOOL success, NSString *responseMessage, NSArray<NSDictionary *> *responseTable) {
    
    for(NSDictionary *row in responseTable){
        
        NSLog(@"row %ld: %@", ([responseTable indexOfObject:row] + 1), row);
        
    }
    
}];

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Conditions That Checks if at Least One of Multiple Conditions are Satisfied

Declaration

+(instancetype) oneOfTheseConditionsAreMet:(NSArray<StackBaseCondition *> *)conditions;

Example

//get the first 3 rows where column 'id' is less than 50 or where column 'id' is greater than 100 
StackBaseCondition *idIsSmallEnough = [StackBaseCondition columnWithName:@"id" isLessThan:@50];
    
StackBaseCondition *idIsBigEnough = [StackBaseCondition columnWithName:@"id" isGreaterThan:@100];

[weakSelf.table getFirst:3 
rowsWhere:[StackBaseCondition oneOfTheseConditionsAreMet:@[idIsSmallEnough, idIsBigEnough]]
completionBlock:^(BOOL success, NSString *responseMessage, NSArray<NSDictionary *> *responseTable) {
    
    for(NSDictionary *row in responseTable){
        
        NSLog(@"row %ld: %@", ([responseTable indexOfObject:row] + 1), row);
        
    }
    
}];

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Note On Combining Conditions

Although these methods exist, not all conditions can be combined. The conditionsAreMet: condition can be combined with other methods. However, the oneOfTheseConditionsAreMet: condition can never be combined with another condition. If it is, the resulting condition will return nil and a description of the problem will be logged.

To be clear, the following theoretical declaration would be okay:

[StackBaseCondition oneOfTheseConditionsAreMet:@[[StackBaseCondition conditionsAreMet:@[...]], otherCondition]];

This, on the other hand, would return a null value:

[StackBaseCondition conditionsAreMet:@[[StackBaseCondition oneOfTheseConditionsAreMet:@[...]], otherCondition]];