Nested Expandable UITableView from Plist in ios

问题

Hi is it possible to use plist to create a expandable table or view in ios?

Here's the plist file and the control type means

0 = Switch

1 = TextField

can I iterate the plist to create a expandable table view? and the output should be this. And if the switch is off all the sub parent of the parent will collapse. I hope someone can help me. Thanks in Advance :D

回答1:

Let's start from basic idea. I'll focus on expand/collapse functionality, ignoring cell types (switches, textfields, whatever). Table view hierarchy is limited with section level and row level. The requirement is to implement any number of nested levels. But we could indent cells using indentationLevel property. Table view would consist of one section with expanded (filtered) cells with level information provided. Therefore, goal is to transform deep plist hierarchy to flat one which is easier to manipulate when populating table view.

The structure of a plist node.

Node contains following properties:

name (cell title)
level (indentation level, hardcoded in plist for simplicity)
collapsed (wether node is collapsed, changed in response of user interaction)
children (child nodes in hierarchy)

Root element must be a dictionary, if you use dictionaryWithContentsOfFile: for plist loading. To keep the order of top level nodes unchanged we use array as a root container.

Data structure

Plist hierarchy is represented by NSMutableDictionary (mutability is required because we will change collapsed property). Table view flat hierarchy is represented by NSMutableArray (stay tuned).

@interface ViewController ()
{
    NSMutableDictionary *_model;
    NSMutableArray *_items;
}
@end

Transform plist hierarchy to flat one

Possible solution is to iterate over all nodes, choose expanded only and add them to a flat array. It could be achieved recursively:

- (void)reloadExpandedItems
{
    for (NSDictionary *item in _model[@"items"]) {
        [_items addObject:item];
        [self reloadExpandedItemsForItem:item];
    }
}

- (void)reloadExpandedItemsForItem:(NSDictionary*)item
{
    if ([item[@"collapsed"] boolValue]) {
        return;
    }

    for (NSDictionary *child in item[@"children"]) {
        [_items addObject:child];
        [self reloadExpandedItemsForItem:child];
    }

    return;
}

Populate table view

We need to set indentation level and respond to user interaction (collapse/expand) cells.

- (NSInteger)tableView:(UITableView *)tableView indentationLevelForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return [_items[indexPath.row][@"level"] integerValue];
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSMutableDictionary *item = _items[indexPath.row];
    item[@"collapsed"] = @(![item[@"collapsed"] boolValue]);  // inverse bool value

    [self reloadItems];
}

- (void)reloadItems
{
    [_items removeAllObjects];
    [self reloadExpandedItems];
    [self.tableView reloadData];
}

reloadItems retransforms plist hierarchy with new changes. If you want to animate changes you need extra logic for inserting/deleting expanded/collapsed cells.

回答2:

look this question. long story short - there no option for standart UITableView class to make it expandable like .plist . you must implement this functionality by your own, or use this example

回答3:

Apple has a sample project that uses data from a plist and populates it using expandable sections in a tableView. Here's the link: https://developer.apple.com/library/ios/samplecode/TableViewUpdates/Introduction/Intro.html

回答4:

This kind of nested TableView can be easily achieved by a very nice Github library RATreeView

Hope this will help.

来源：https://stackoverflow.com/questions/21773856/nested-expandable-uitableview-from-plist-in-ios

标签

ios

objective-c

uitableview

plist