Hiding fields

[j-dawg]

I'm programming a form which only certain fields are required based on previous fields.

I'm having trouble hiding certain fields conditionally, I was wondering if this is native functionality?

[wm-j-ray]

I had the same issue, so maybe I can help.

You can handle this using some additions to your form model. I had certain sections that I wanted to appear or be hidden based on the value of some other field. What I did was used excludedFields to manage the entire form rather than the Fields array.

At a high level, I created methods that created the list(s) of fields I wanted to toggle and then some helper methods to manage the form by adjusting the array returned by [form excludedFields].

What I did was in the form model I created something like this:

 -(NSArray *) characterAttributesFields {
return @[@"species",
         @"sex",
         @"age",
         @"hair",
         @"eyes",
         @"build",
         @"intelligence",
         @"profession"
         ];
 }

I did one of these for each clump of form field/properties I wanted to manage. (As an aside, I used a separate NSDictionary to control the individual stylings of each field. Just seemed a little easier to maintain). I created a property for an array of dynamicallyExcludedFields and I'd use methods to adjust the contents of this array.

Then I used these lists and some helper methods to adjust what gets returned by [excludedFields), like so:

 - (NSArray *)excludedFields
 {

     NSMutableArray *excluded = [[NSMutableArray alloc] init];

     [excluded addObjectsFromArray:[self alwaysExcludedFields]];
     if ([_dynamicallyExcludedFields count]) {
         for (id excludeMeToo in _dynamicallyExcludedFields) {
             [excluded addObject:excludeMeToo];
         }
     }
     return excluded;
 }

So the above method just adjusts what is returned. It probably seems a little counter-intuitive that you manage the form contents by the contents of the excludedFields array rather than the Fields array, but that is the only way I could figure out how to do it.

Read a field value filled in by user Adjust dynamically excludedFieldsArray reload the form

wash, rinse, repeat

I'm sure there is a more clever way of getting the job done, but hey, what do I know?

Hope this helps.

//**********

Here are some of the helper methods that may save you a little hassle:

 -(NSArray *) alwaysExcludedFields {
     return @[@"dynamicallyExcludedFields",
         @"isNewCharacter"
         ];
 }




 -(void) addToExcludedFields: (NSString *)fieldName {
     bool alreadyThere = [_dynamicallyExcludedFields containsObject:fieldName];
     if (!alreadyThere) {
         [_dynamicallyExcludedFields addObject:fieldName];
     }
 }

 -(void) dropFromExcludedFields: (NSString *)fieldName {
     bool isThere = [_dynamicallyExcludedFields containsObject:fieldName];
     if (isThere) {
         [_dynamicallyExcludedFields removeObject:fieldName];
     }
}

And finally a cover function or two that will fire based on the value of some other field:

 -(void) addCharacterAttributesFieldsToForm {
     for (id obj in [self characterAttributesFields]) {
         [self dropFromExcludedFields:obj];
     }
}

 -(void) dropCharacterAttributesFieldsFromForm {
     for (id obj in [self characterAttributesFields]) {
         [self addToExcludedFields:obj];
     }
     NSLog(@"Excluded Fields: %@",self.excludedFields);  
}

[j-dawg]

Thank you.

I wrote a Swift solution, which is quite different to your suggestion but I thought you might find interesting.

I added a FXFormFieldAction to the switch field, which calls a function containing

self.formController.form = self.formController.form
self.tableView.reloadData()

Then within the func fields() -> [AnyObject]! { function, I create an NSMutableArray to which I can conditionally add fields to before returning.

This solution works great, the only thing I am lacking is the ability to make the change in fields animated.