[英]Cascading parent child select boxes from dynamic JSON data
我已经从JSON数据动态创建了一些链式选择框,我将从服务器收到这些数据。 链接/级联的工作方式是每个选择框都是具有以下属性的命名对象:
选项:选项对象的数组,其中每个对象包含:(a)选项值(b)父选项值 - 用于映射当前值的父选择框值。 (c)选项ID。
选定选项:具有两个属性的对象:(a)当前选定的值(b)当前所选值的ID。
我在“选项”标签中使用ng-repeat创建选择框,或者在“select”标签中使用ng-option,然后我使用自定义过滤器,我通过匹配父选项值来过滤检索到的选项(2) (2> b)选项值(2> a)与其父对象的“当前选择值”(3> a)。 基本上使用自定义过滤器从子选项值到选定父值进行多对一映射。
我能够正确映射父子选择框,但问题是当我更改父选择框值时,其子对象的“选定选项值”不会更新( 子选择的项目不会抓取筛选列表中的第一项,导致孙子下拉不更新。 ) [1]
有没有办法,如果父值更改,子选择框(以及后续的子/孙)使用第一个选项值而不是当前空白值初始化?
这是工作的plunker。 (ng-repeat实施)。 真的很感激任何帮助。
HTML(ng-repeat):
<div ng-repeat="selection in vm.selectionData">
<div ng-repeat="(key, attribute) in selection.attributes">
<span>{{key}}</span>
<select class="form-control" ng-model="attribute.selectedOption.name">
<option ng-repeat="option in attribute.options | optionFilter : selection.attributes[attribute.parentAttr]">{{option.name}}</option>
</select>
</div>
</div>
HTML(ng-options):
<div ng-repeat="selection in vm.selectionData">
<div ng-repeat="(key, attribute) in selection.attributes">
<span>{{key}}</span>
<select ng-model="attribute.selectedOption" ng-options="attribute.name for attribute in (attribute.options | optionFilter : selection.attributes[attribute.parentAttr]) track by attribute.id">
</select>
</div>
</div>
JS:
myApp.filter('optionFilter', function() {
return function(items, parent) {
var result = [];
if (parent) {
for (var i = 0; i < items.length; i++) {
console.log(items[0].parent, parent.selectedOption.name);
if (items[i].parent === parent.selectedOption.name) {
result.push(items[i]);
}
}
return result;
} else {
return items;
}
}
});
myApp.controller("MyCtrl", function($scope) {
this.selectionData = [{
selectionType: "Geography",
attributes: {
country: {
parentAttr: "none",
options: [{
name: "India",
parent: "None",
id: 1
}, {
name: "Bangladesh",
parent: "None",
id: 2
}, {
name: "Afganistan",
parent: "None",
id: 3
}],
selectedOption: {
name: "India",
id: 1
}
},
state: {
parentAttr: "country",
options: [{
name: "Rajasthan",
parent: "India",
id: 1
}, {
name: "Haryana",
parent: "India",
id: 2
}, {
name: "Dhaka",
parent: "Bangladesh",
id: 3
}, {
name: "Kabul",
parent: "Afganistan",
id: 4
}],
selectedOption: {
name: "Rajasthan",
id: 1
}
},
city: {
parentAttr: "state",
options: [{
name: "Kota",
parent: "Rajasthan",
id: 1
}, {
name: "Sirsa",
parent: "Haryana",
id: 2
}, {
name: "Alwar",
parent: "Rajasthan",
id: 3
}, {
name: "Gurgaon",
parent: "Haryana",
id: 4
}, {
name: "Kabul",
parent: "Kabul",
id: 5
},{
name: "Dhaka",
parent: "Dhaka",
id: 6
}
],
selectedOption: {
name: "Kota",
id: 1
}
}
},
}];
});
参考文献:
经过一段时间的努力,我想出了一个解决方案(虽然不确定它是否符合最佳实践)。 在我的自定义过滤器中,它根据父对象的选定选项值返回已过滤的选项,我另外发送当前的选择框对象。 然后,
在这里工作演示。 请分享是否有更好的解决方案。 以下是自定义过滤器:
myApp.filter('optionFilter', function() {
return function(items, parent, self) {
var result = [];
if (parent) {
for (var i = 0; i < items.length; i++) {
if (parent.selectedOption !== null && items[i].parentValue === parent.selectedOption.value) {
result.push(items[i]);
}
}
if (self.selectedOption === null) {
self.selectedOption = result[0];
}
return result;
} else {
return items;
}
}
});
HTML:
<div ng-repeat="(key, item) in data">
<span>{{key}}</span>
<select ng-model="item.selectedOption" ng-options="option.value for option in (item.availableOptions | optionFilter : data[item.parent] : item) track by option.id">
</select>
</div>
数据:
this.data = {
Country: {
parent: "None",
availableOptions: [{
value: "United States",
parentValue: "None",
id: 1
}, {
value: "China",
parentValue: "None",
id: 2
}, {
value: "India",
parentValue: "None",
id: 3
}],
selectedOption: {
value: "United States",
parentValue: "None",
id: 1
}
},
State: {
parent: "Country",
availableOptions: [{
value: "California",
parentValue: "United States",
id: 1
}, {
value: "Shanghai",
parentValue: "China",
id: 2
}, {
value: "Delhi",
parentValue: "India",
id: 3
}],
selectedOption: {
value: "California",
parentValue: "United States",
id: 1
}
},
City: {
parent: "State",
availableOptions: [{
value: "Greenfield",
parentValue: "California",
id: 1
}, {
value: "Shanghai",
parentValue: "Shanghai",
id: 2
}, {
value: "New Delhi",
parentValue: "Delhi",
id: 3
}],
selectedOption: {
value: "Greenfield",
parentValue: "California",
id: 1
}
}
};
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