I am looking to flatten a nested object in my controller (new to Loopback and Typescript)
Here is my model :
export class SampleModel {
id: number;
code: number;
guide?: string;
gradeData?: string;
}
Here is an example object :
{
"id": 1,
"code": 12345,
"guide": "Guide for 2021",
"gradeData": {
"en": "Eng grade",
"de": "Ger grade"
}
}
Here is my controller:
// returns an array of SampleModel objects
@get('/guides')
async find(
@param.query.string('lang') lang: string,
@param.filter(SampleModel) filter?: Filter<SampleModel>
): Promise<SampleModel[]> {
return this.sampleModelRepository.find(filter); //this returns Promise<SampleModel[]>
}
I want to tweak this response a little based on lang. For ex: if lang = en I want the response to look like
[
{
"id": 1,
"code": 12345,
"guide": "Guide for 2021",
"gradeData": "Eng grade"
}
]
Something like this? Ofcource you need to make the langcode dynamic
[{
"id": 1,
"code": 12345,
"guide": "Guide for 2021",
"gradeData": {
"en": "Eng grade",
"de": "Ger grade"
}
}].map(e=>{
e.gradeData = e.gradeData["en"];
return e;
})
Returned object:
[
{
"id": 1,
"code": 12345,
"guide": "Guide for 2021",
"gradeData": "Eng grade"
}
]
Thanks to @Firewizz I was able to do this. Here is my updated controller :
// returns an array of SampleModel objects
@get("/guides")
async find(
@param.query.string("lang") lang: string,
@param.filter(SampleModel) filter?: Filter<SampleModel>
): Promise<SampleModel[]> {
const res = this.sampleModelRepository.find(filter); //this returns Promise<SampleModel[]>
if (lang != null) {
(await res).map((e) => {
if (e.gradeData != null && e.gradeData.hasOwnProperty(lang)) {
e.gradeData = new Map(Object.entries(e.gradeData)).get(locale);
// not sure why this is required but when I tried
// `e.gradeData = e.gradeData[locale];`
// I get compilation error " Element implicity has an 'any' type because index expression is not of type 'number' " maybe because gradeData is defined as a String but when I do
// console.log(typeof e.gradeData)
// I get object
// I also tried
// `e.gradeData = JSON.parse(e.gradeData)[locale];`
// I get " SyntaxError: Unexpected token o in JSON at position 1 " and that could be because it's already an object
// I then tried
// `e.gradeData = JSON.parse(JSON.stringify(e.gradeData))[locale];`
// this also works but I think converting this to a map as a workaround is better
}
return e;
});
}
return res;
}