我正从Angular Service中的PouchDB中检索文档 . 以下列格式检索文档:
{
"_id":"segments",
"_rev":"1-4f0ed65cde23fe724db13bea1ae3bb13",
"segments":[
{ "name":"Aerospace" },
{ "name":"Auto repair" },
{ "name":"Commercial" },
{ "name":"Education" },
{ "name":"Energy" },
{ "name":"Farm/ranch" },
{ "name":"Furniture" },
{ "name":"Heavy Equipment" },
{ "name":"Hobbyist" },
{ "name":"Infrastructure" },
{ "name":"Luxury/Leisure" },
{ "name":"Military" },
{ "name":"MUP" },
{ "name":"Processing" },
{ "name":"Rail" },
{ "name":"Transportation" }
]}
我想将它映射到一个新的数组,看起来像:
[
{ value: "Aerospace", viewValue: "Aerospace" },
{ value: "Auto Repair", viewValue: "Auto Repair" },
{ value: "Commercial", viewValue: "Commercial" }
...
]
为此,我在我的服务中尝试了这段代码:
getSegments(): Observable<any[]> {
return from(this.database.get('segments'))
.pipe(
map((results) => results.segments)
);
}
我在我的Component中转换数组,如下所示:
segments: SegmentsLookup[] = [];
...
this.lookupDbService.getSegments()
.subscribe(data => {
data.forEach(element => {
this.segments.push({value: element.name, viewValue: element.name});
});
});
这有效,但我知道有一种方法可以在服务代码中正确地映射它 . 此外,当以这种方式完成时,编译器会抱怨“'{}'”类型中的“results.segments " stating "属性"segments"” .
如何在Service的“getSegments”方法中将检索到的数据映射到我需要的数组?
2 回答
你可以做转换是两步:
pipe / map来提取段
array / map转换为最终数据类型
请在此处查看示例:https://stackblitz.com/edit/angular-ikb2eg?file=src%2Fapp%2Fapp.component.ts
您可以扩展map函数并将其从组件中删除,如下所示: