Dynamically add dimensions to boolean array - flutter

Question

I'm using flutter to develop an e-commerce app.
I'm working on the navDrawer for it and I could use some help with the categories.
I have categories that can have subcategories and the subcategories can also have their own subcategories.
Basically, the data set is an array of unknown dimensions.
I need to make a boolean map for my categories and subcategories so that I can keep track of which ones are open in order to show the subcategories.
Here's an example of the dataset:
{
"id":"41490",
"name":"Electrical Equipment",
"subCategories":[
{
"id":"41492",
"name":"Breakers",
"subCategories":[
{
"id":"167542",
"name":"1 Pole",
"subCategories":[
{
"id":"167577",
"name":"15 Amp",
"subCategories":null
},
{
"id":"167585",
"name":"20 Amp",
"subCategories":null
},
{
"id":"167600",
"name":"30 Amp",
"subCategories":null
},
{
"id":"167606",
"name":"40 Amp",
"subCategories":null
}
]
},
I think recursion is the optimal way to process this dataset but the problem I'm having is that I can't figure out how to have dynamic dimensions for an array in Dart.
I already figured out how to generate my listTiles from the dataset but I can't figure out the boolean map.
Is this even possible or should I look into a different approach?
Here's my code for generating the listTiles from the dataset:
void setCategories(List categories){
_categories = categories;
int catCount = categories.length;
_categoryList = new ListView.builder(
//shrinkWrap: true,
//physics: ClampingScrollPhysics(),
padding:EdgeInsets.all(0.0),
itemCount: catCount,
itemBuilder: (BuildContext context, int index) => buildCategories(context, index),
);
}
Widget buildCategories(BuildContext context, int index){
if(_categories[index]['subCategories']!=null){
//TODO: call buildSubCategories with depth of 1 parameter
return Container(
height: 30.0,
child: ListTile(
title: Row(
children:[
Text(" "+_categories[index]['name']),
Transform.scale(
scale: 0.75,
child:
Icon(Icons.arrow_back)
)
]
),
onTap: () {
//TODO: implement boolean map here
}
),
padding: EdgeInsets.all(0.0),
margin: EdgeInsets.all(0.0)
);
} else {
return Container(
height: 30.0,
child: ListTile(
title: Text(" "+_categories[index]['name']),
onTap: () {
}
),
padding: EdgeInsets.all(0.0),
margin: EdgeInsets.all(0.0)
);
}
}
Widget buildSubCategories(var parent, int depth){
List subCategoryList = parent['subCategories'];
int subCategoryCount = subCategoryList.length;
if(parent['subCategories']!=null){
//for each subCategory
//if subCategory has subCategories
//recurse subCategory with depth
buildSubCategories(parent['subCategories'], depth++);
//TODO: implement boolean map here
} else {
//
}
}
void generateCategoryBooleanMap(){
//TODO: generate boolean map here
//TODO: boolean map needs to have a undetermined amount of depth levels
}
Any insight is appreciated even if it means I have to use a different paradigm.

Answer 1

Example of using a Set to keep track of which id is open:
void main() {
final idHandler = IdHandler();
print(idHandler.isIdOpen('MyId')); // false
idHandler.openId('MyId');
print(idHandler.isIdOpen('MyId')); // true
idHandler.closeId('MyId');
print(idHandler.isIdOpen('MyId')); // false
idHandler.openId('MyId');
print(idHandler.isIdOpen('MyId')); // true
idHandler.closeAll();
print(idHandler.isIdOpen('MyId')); // false
}
class IdHandler {
final Set<String> _openIds = {};
void openId(String id) => _openIds.add(id);
void closeId(String id) => _openIds.remove(id);
void closeAll() => _openIds.clear();
bool isIdOpen(String id) => _openIds.contains(id);
}