home *** CD-ROM | disk | FTP | other *** search
/ NeXT Enterprise Objects Framework 1.1 / NeXT Enterprise Objects Framework 1.1.iso / NextDeveloper / Examples / EnterpriseObjects / Validation / Validation.subproj / ValidatingDelegate.m < prev   
Encoding:
Text File  |  1995-02-17  |  4.8 KB  |  147 lines
  1. #import "ValidatingDelegate.h"
  2. #import "KeyValueValidation.h"
  3.  
  4. @implementation ValidatingDelegate
  5.  
  6. - (void)setValidatesImmediately:(BOOL)yn
  7. {
  8.     validatesImmediately = yn;
  9. }
  10.  
  11. - (BOOL)validatesImmediately
  12. {
  13.     return validatesImmediately;
  14. }
  15.  
  16. - (void)reportValidationError:(NSString *)message forKey:(NSString *)key ofObject:object inController:(EOController *)controller
  17. {
  18.     NSString *title;
  19.     title = [NSString stringWithFormat:@"Invalid input for: %@", key];
  20.  
  21.     // Let's make sure that the object with the error is selected
  22.     [controller setSelectionIndexes:[NSArray arrayWithObject:
  23.         [NSNumber numberWithInt:[[controller allObjects] indexOfObjectIdenticalTo:object]]]];
  24.  
  25.     NXRunAlertPanel([title cString], [message cString], "OK", NULL, NULL);
  26.  
  27.     // we could tell the controller to select the invalid object and
  28.     // run through the associations and restore focus to the one
  29.     // matching the key
  30. }
  31.  
  32. - (void)reportValidationErrors:(NSDictionary *)errors forObject:object inController:(EOController *)controller
  33. {
  34.     // pick one of the errors and display it
  35.     NSEnumerator *errorEnum = [errors keyEnumerator];
  36.     NSString *badValueKey, *errorMessage;
  37.     badValueKey = [errorEnum nextObject];
  38.     errorMessage = [errors objectForKey:badValueKey];
  39.  
  40.     [self reportValidationError:errorMessage forKey:badValueKey ofObject:object
  41.         inController:controller];
  42. }
  43.  
  44. - (NSDictionary *)controller:(EOController *)controller willSaveEdits: (NSDictionary *)edits toObject:object;
  45. {
  46.     if (validatesImmediately) {
  47.         NSMutableDictionary *converted = [NSMutableDictionary dictionaryWithCapacity:[edits count]];
  48.         NSEnumerator *editEnum = [edits keyEnumerator];
  49.         NSString *key;
  50.         NSDictionary *errors;
  51.  
  52.         while (key = [editEnum nextObject]) {
  53.             // construct a selector and see if the have a validation method
  54.             id value = [[controller dataSource] coerceValue:[edits objectForKey:key] forKey:key];
  55.             if (!value) {
  56.                 [self reportValidationError:@"Value entered is not of correct type"
  57.                     forKey:key ofObject:object inController:controller];
  58.                 return nil;
  59.             }
  60.  
  61.             [converted setObject:value forKey:key];
  62.         }
  63.  
  64.         errors = [object validateValuesInDictionary:converted];
  65.         if([errors count]) {
  66.             [self reportValidationErrors:errors forObject:object inController:controller];
  67.             // [controller discardEdits];  // throw away the bad values
  68.             return nil;
  69.         }
  70.         return converted;
  71.     }
  72.     return edits;
  73. }
  74.  
  75.  
  76. - (EODataSourceOperationDelegateResponse)controller:(EOController *)controller
  77.     willInsertObject:object
  78.     inDataSource:dataSource
  79. {
  80.     if ([object respondsToSelector:@selector(validForInsertInDataSource:)]) {
  81.         NSDictionary *errors = [object validForInsertInDataSource:dataSource];
  82.         if (errors) {
  83.             [self reportValidationErrors:errors forObject:object inController:controller];
  84.             return EORollbackDataSourceOperation;
  85.         }
  86.     }
  87.     return EOPerformDataSourceOperation;
  88. }
  89.  
  90. - (EODataSourceOperationDelegateResponse)controller:(EOController *)controller
  91.     willUpdateObject:object
  92.     inDataSource:dataSource
  93. {
  94.     if ([object respondsToSelector:@selector(validForUpdateInDataSource:)]) {
  95.         NSDictionary *errors = [object validForUpdateInDataSource:dataSource];
  96.         if (errors) {
  97.             [self reportValidationErrors:errors forObject:object inController:controller];
  98.             return EORollbackDataSourceOperation;
  99.         }
  100.     }
  101.     return EOPerformDataSourceOperation;
  102. }
  103.  
  104. - (EODataSourceOperationDelegateResponse)controller:(EOController *)controller
  105.     willDeleteObject:object
  106.     inDataSource:dataSource
  107. {
  108.     if ([object respondsToSelector:@selector(validForDeleteInDataSource:)]) {
  109.         NSDictionary *errors = [object validForDeleteInDataSource:dataSource];
  110.         if (errors) {
  111.             [self reportValidationErrors:errors forObject:object inController:controller];
  112.             return EORollbackDataSourceOperation;
  113.         }
  114.     }
  115.     return EOPerformDataSourceOperation;
  116. }
  117. @end
  118.  
  119.  
  120. @implementation NSObject (ValidationProtocols)
  121. // An EO can implement some or all of these methods to play a roll in its validation
  122. - (NSArray *)keysToValidate
  123. {
  124.     return [NSArray array];
  125. }
  126.  
  127. - (NSDictionary *)validForDataSource:(id <EODataSources>)dataSource;
  128. {
  129.     return [self validateValuesInDictionary:[self valuesForKeys:[self keysToValidate]]];
  130. }
  131.  
  132. - (NSDictionary *)validForInsertInDataSource:(id <EODataSources>)dataSource;
  133. {
  134.     return [self validForDataSource:dataSource];
  135. }
  136.  
  137. - (NSDictionary *)validForUpdateInDataSource:(id <EODataSources>)dataSource;
  138. {
  139.     return [self validForDataSource:dataSource];
  140. }
  141.  
  142. - (NSDictionary *)validForDeleteInDataSource:(id <EODataSources>)dataSource;
  143. {
  144.     return nil;
  145. }
  146. @end
  147.