检查项目是否有价值 'required'

Question

所以我做了一个调查表，data/question 来自 api 每个数据项都有键 'required' 如果问题答案还没有填写按钮去下一页不可用。如何为它设置 if else 条件？

The form

The data

{
      "success": true,
      "msg": "OK",
      "data": [
        {
          "id": 4,
          "label":
              "Is this a test ride period or demonstration period in this PoC?",
          "required": true,
          "options": [
            {"label": "Test ride", "value": "1"},
          ],
        },
        {
          "id": 3,
          "label": "Have you answered this survey before?",
          "required": true,
          "options": [
            {"label": "No, for the first time", "value": "1"},
          ],
        }
      ]
    },

Answer 1

一种方法是使用来自选项的小部件的回调。

class Data {
 int id; // Will be unique
 String label;
 bool requireds;
 List<Map<String, String>> options;
 bool added; // Add an extra parameter in the class to manage if the value is selected or not.

 Data({
  required this.id,
  required this.label,
  required this.requireds,
  required this.options,
  this.added = false, // Set the default value as false
 });
}

// Contains the list of data objects
List<Data> listData = [...];

// Callback from widgets to the parent widget
void updateData(bool isAdded, int id) {
 listData.firstWhere((element) => element.id == id).added = true; // Update the added bool to true whenever a value is selected for the widget
}

// On click condition, can be added to state updater as well to make
// the button disabled or enabled
void checkConditions() {
  List<Data> filter = [];
  filter.addAll(listData);
  // Filter the list for the condition
  filter.retainWhere((data){
    return data.requireds && !data.added; // If required and not added
  });

  // If the filter list is empty then all the required fields are answered
  if (filter.isEmpty) {
    // Go to next page or do an operation
  } else {
    // Do operation based on filter list values
  }
}

这是我在 dart 中编写的代码片段，尚未在 Flutter 项目中尝试过。让我知道这是否有帮助或您遇到其他问题。

检查项目是否有价值 'required'

Checking if item have value 'required'

api

json

dart

flutter