FlutterFlow is a powerful visual app builder that allows you to create fully functional mobile and web applications without writing extensive code. While it provides many built-in components, sometimes you need a more tailored solution. In this blog, we’ll walk you through the process of creating a custom multi-item picker widget in FlutterFlow.

Why a Multi-Item Picker?

A multi-item picker is essential when users need to select more than one option from a list. Common use cases include selecting interests, tags, categories, or filtering items in e-commerce and survey apps.

FlutterFlow doesn’t have a built-in multi-select component, but with the help of custom widgets, you can easily build one that integrates seamlessly into your app.

Step 1: Set Up Your Custom Widget in FlutterFlow

To start, create a new custom widget in FlutterFlow:

1. Go to the Custom Code section in the left panel.
2. Under Widgets, click + Add.
3. Name it something like MultiItemPickerComponent.
4. Define the parameters:

• items (List, required): The list of all items to display.
• initialSelectedItems (List, optional): The list of items that should appear pre-selected.
• title (String, optional): Title of the picker UI.
• searchHintText (String, optional): Placeholder for the search input field.
• width, height, maxHeight (optional): For layout customization.

Step 2: Writing the Widget Code

Here’s a simplified version of a FlutterFlow-compliant widget (no function callbacks):

// Automatic FlutterFlow imports
import '/flutter_flow/flutter_flow_theme.dart';
import '/flutter_flow/flutter_flow_util.dart';
import '/custom_code/widgets/index.dart'; 
import '/flutter_flow/custom_functions.dart'; 
import 'package:flutter/material.dart';
// Begin custom widget code
// DO NOT REMOVE OR MODIFY THE CODE ABOVE!

class MultiItemPickerComponent extends StatefulWidget {
  const MultiItemPickerComponent({
    Key? key,
    this.width,
    this.height,
    required this.items,
    this.initialSelectedItems,
    this.searchHintText = 'Search items...',
    this.title = 'Select Items',
    // this.buttonText = 'Done',
    this.maxHeight,
  }) : super(key: key);

  final double? width;
  final double? height;
  final double? maxHeight;
  final List<String> items;
  final List<String>? initialSelectedItems;
  final String searchHintText;
  final String title;
  // final String buttonText;

  @override
  _MultiItemPickerComponentState createState() =>
      _MultiItemPickerComponentState();
}

class _MultiItemPickerComponentState extends State<MultiItemPickerComponent> {
  final TextEditingController _searchController = TextEditingController();
  List<String> _filteredItems = [];
  List<String> _selectedItems = [];

  @override
  void initState() {
    super.initState();
    _filteredItems = widget.items;
    _selectedItems = widget.initialSelectedItems ?? [];
    _searchController.addListener(_filterItems);
  }

  @override
  void dispose() {
    _searchController.removeListener(_filterItems);
    _searchController.dispose();
    super.dispose();
  }

  void _filterItems() {
    final query = _searchController.text.toLowerCase();
    setState(() {
      _filteredItems = widget.items
          .where((item) => item.toLowerCase().contains(query))
          .toList();
    });
  }

  void _toggleItemSelection(String item) {
    setState(() {
      if (_selectedItems.contains(item)) {
        _selectedItems.remove(item);
      } else {
        _selectedItems.add(item);
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      width: widget.width ?? double.infinity,
      height: widget.height,
      constraints: BoxConstraints(
        maxHeight: widget.maxHeight ?? 400,
      ),
      decoration: BoxDecoration(
        color: Theme.of(context).cardColor,
        borderRadius: BorderRadius.circular(8),
        boxShadow: [
          BoxShadow(
            blurRadius: 4,
            color: Color(0x33000000),
            offset: Offset(0, 2),
          ),
        ],
      ),
      child: Padding(
        padding: EdgeInsets.all(16),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Text(widget.title,
                    style: Theme.of(context).textTheme.titleMedium),
                Text('${_selectedItems.length} selected',
                    style: Theme.of(context).textTheme.bodySmall),
              ],
            ),
            SizedBox(height: 12),
            TextFormField(
              controller: _searchController,
              decoration: InputDecoration(
                hintText: widget.searchHintText,
                border: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(8),
                ),
                prefixIcon: Icon(Icons.search),
                suffixIcon: _searchController.text.isNotEmpty
                    ? InkWell(
                        onTap: () {
                          _searchController.clear();
                        },
                        child: Icon(Icons.clear),
                      )
                    : null,
              ),
            ),
            SizedBox(height: 12),
            Text('Selected Items:',
                style: TextStyle(fontWeight: FontWeight.bold)),
            Wrap(
              spacing: 8,
              runSpacing: 8,
              children: _selectedItems.map((item) {
                return Chip(
                  label: Text(item),
                  onDeleted: () => _toggleItemSelection(item),
                );
              }).toList(),
            ),
            SizedBox(height: 12),
            Text('Available Items:',
                style: TextStyle(fontWeight: FontWeight.bold)),
            Expanded(
              child: ListView.builder(
                itemCount: _filteredItems.length,
                itemBuilder: (context, index) {
                  final item = _filteredItems[index];
                  final isSelected = _selectedItems.contains(item);
                  return ListTile(
                    title: Text(item),
                    trailing: Icon(
                      isSelected
                          ? Icons.check_box
                          : Icons.check_box_outline_blank,
                      color: isSelected
                          ? Theme.of(context).colorScheme.primary
                          : null,
                    ),
                    onTap: () => _toggleItemSelection(item),
                  );
                },
              ),
            ),
            SizedBox(height: 16),
          ],
        ),
      ),
    );
  }
}

Step 3: Use the Widget in Your UI

Now that your widget is added:

1. Drag the MultiItemPickerComponent widget from the Custom Widgets tab.
2. Pass the items list and optionally initialSelectedItems, title, or searchHintText.
3. To retrieve selected items, bind the selected items to a local state or AppState variable using Actions in FlutterFlow.

For example:

• On done/tap, update an AppState list variable with selected items using a custom action or logic.

Conclusion

With this custom widget, you now have a robust multi-item picker that works beautifully within the FlutterFlow environment. This approach offers flexibility, search capability, and a user-friendly interface.

This pattern — building custom widgets without callback parameters — can be reused for other advanced components. Happy building!

From Our Parent Company Aeologic

Aeologic Technologies is a leading AI-driven digital transformation company in India, helping businesses unlock growth with AI automation, IoT solutions, and custom web & mobile app development. We also specialize in AIDC solutions and technical manpower augmentation, offering end-to-end support from strategy and design to deployment and optimization.

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