Grouping core data tableView rows in manually created sections
I have a Company
entity with about 20 fields and I'm wanting to use a grouped tableView with manually created section headers (ie: General, Financial, Misc.), but I am unsure of how to make Core Data understand how to treat these section headers and make them relate only to the data I want to show in these groups.
For example, name, logo, etc would go under General, budgets, cash would go under financial, etc.
Basically, I want to control what data from Core data gets put into each category and display it.
In the Core books sample there is this code:
/*
The data source methods are handled primarily by the fetch results controller
*/
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return [[fetchedResultsController sections] count];
}
// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)secti开发者_Go百科on {
id <NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
}
But how do I make it understand that the sections aren't in Core data, but created manually?
I've got an answer to my problem now, I do not know if its the correct approach, but it is working and would welcome comments.
Just to clarify what the problem was, and what I was trying to do.
I have a core data entity company
with about 10 or so fields inside them, however rather than listing them all in one go, I wanted to group the outputted fields.
For example, I have about 6 fields relating to cash such as "cash", "marketingBudget", "seoBudget", etc and I wanted to group this data on the tableView, but the problem was I didn't know how to set up a relationship so that table.field.x belonged to group.x, and so on.
The answer I came to was to use a PLIST/dictionary that pretty much mirrors the structure of the core data entity; and assign the structure to the groups I want to display.
My dictionary looks like this;
(root)
->CompanyTpl (array)
--> Item 0 (Dictionary)
---> Section (String) = "General"
---> Children (Array ) ------> Item 0 (Dictionary)
----------> Key = "name"
----------> Value = "Company Name" ...
Where the Key
would be a reference for Core Data to use and display its contents, if required.
Where the Value
would be would to display at the cellForRowAtIndexPath.
So, in my code I basically went through the section (by which I mean tableView section) and then find the correlating children info from the PLIST; and get the Key/Value and use this as and when required.
Here is a cut down version of the code.
- (void)viewDidLoad {
NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"CompanyTpl" ofType:@"plist"];
self.companyDictionary = [[NSDictionary dictionaryWithContentsOfFile:plistPath] retain];
// self.tableDataSource is a NSMutableArray
self.tableDataSource = [self.companyDictionary objectForKey:@"CompanyTpl"];
// Debugging info
NSLog(@"Section = 0");
NSLog(@"%@", [self.tableDataSource objectAtIndex:0]);
NSLog(@"Section Name = %@", [[self.tableDataSource objectAtIndex:0] objectForKey:@"Section"]);
NSArray *sectionChildren = [[self.tableDataSource objectAtIndex:0] objectForKey:@"Data"];
NSLog(@"Section Children = %@", sectionChildren);
NSLog(@"Count of Section Children = %d", [sectionChildren count]);
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return ([self.tableDataSource count]);
}
// Section header
-(NSString*)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
NSString *title = nil;
title = [[self.tableDataSource objectAtIndex:section] objectForKey:@"Section"];
return title;
}
// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSInteger rows = 0;
NSArray *sectionChildren = [[self.tableDataSource objectAtIndex:section] objectForKey:@"Data"];
NSLog(@"Section Children = %@", sectionChildren);
NSLog(@"Count of Section Children = %d", [sectionChildren count]);
rows = [sectionChildren count];
return rows;
}
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSArray *sectionChildren = [[self.tableDataSource objectAtIndex:indexPath.section] objectForKey:@"Data"];
NSDictionary *sectionChildrenData = [sectionChildren objectAtIndex:indexPath.row];
//NSLog(@"Section Children data = %@", sectionChildrenData);
NSString *scKey = [sectionChildrenData objectForKey:@"Key"];
NSString *scValue = [sectionChildrenData objectForKey:@"Value"];
NSLog(@"scKey = %@", scKey);
// Grab the data from Core Data using the scKey
static NSString *CellIdentifier = @"defaultCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
//cell.textLabel.text = @"test";
cell.textLabel.text = scValue;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
return cell;
}
The idea would be that I can use the KEY when referencing Core Data to grab its contents and display it on the tableView controller at cellForRowAtIndexPath cell.textLabel.text value.
One could go a little further in depth and have more info in the PLIST such as what the subtitle should be, etc.
Anyway, would welcome comments and thoughts.
Thanks.
I have got a little closer to an answer, but I am still having trouble hooking up core data items so that they are in certain sections.
#pragma mark -
#pragma mark Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
//return [[fetchedResultsController sections] count];
//NSLog(@"%d", [self.sectionArray count] );
return 4;
}
// Section header
-(NSString*)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
NSString *title = nil;
switch (section) {
case 0:
title = @"General";
break;
case 1:
title = @"Finanical";
break;
case 2:
title = @"Category A";
break;
case 3:
title = @"Category B";
break;
case 4:
title = @"Misc";
break;
default:
break;
}
return title;
}
// Customize the number of rows in the table view.
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
/*
id <NSFetchedResultsSectionInfo> sectionInfo = [[fetchedResultsController sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
*/
NSInteger rows = 0;
// The number of rows depend on the section
switch (section) {
case 0:
rows = 2;
break;
case 1:
rows = 3;
break;
case 2:
rows = 4;
break;
default:
break;
}
return rows;
}
What this does is manually create 4 sections, the names don't matter at the moment, and then I create a different number of rows for each section.
So far, so good.
The problem I'm having is making Core Data understand that in section0.row0 I want the textLabel to say the the company name etc.
I'm thinking that all of this has to be in a dictionary, laying-out the entire structure that I want, and the labels to display; and then in cellForRowAtIndexPath I display the array within the dictionary that I want.
ie:
[root] CompanyTpl (array)
--> Item 0 (dictionary)
-----> Category (string) = "General"
-----> Data (Array)
---------> Item 0 (Dictionary)
---------------> cdFieldName: name
---------------> display: "Company name"
Where cdFieldName is a reference to the field name within Core Data I want to display.
If there is an alternative way to do this, I'd be interested in finding out.
Thanks.
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