环回 - 远程方法和扁平化相关模型查询结果

Question

我正在使用Loopback 3开发一个应用程序。 我在服务评估模型上创建了一个远程方法，以返回服务模型中的服务评估和相关属性的列表。

ServiceEvaluation.evaluationList = function(cb) {
ServiceEvaluation.find({
fields: {
status: true,
createdAt: true,
serviceId: true
},
include: {
relation: 'rel_ServiceEval_Service',
scope: {
fields: {
serviceName: true,
supplierId: true
}
}
}
}, function(err, response) {
cb(null, response);
});
};

当从返回的 API 资源管理器调用时，上述工作有效;

{
"list": [
{
"status": "Draft",
"serviceId": "5b8e215d81c76325b409b960",
"createdAt": "2018-09-04T06:08:29.623Z",
"rel_ServiceEval_Service": {
"serviceName": "Workplace software and SaaS",
"id": "5b8e215d81c76325b409b960",
"supplierId": "5b8e215d81c76325b409b949"
}
}, ...

但是，我想要返回要在数据网格中显示的平展对象数组，而不是返回带有嵌入对象的对象数组。 以下是这样做的尝试。

ServiceEvaluation.evaluationList = function(cb) {
ServiceEvaluation.find({
fields: {
status: true,
createdAt: true,
serviceId: true
},
include: {
relation: 'rel_ServiceEval_Service',
scope: {
fields: {
serviceName: true,
supplierId: true
}
}
}
}, function(err, response) {
var responseLength = response.length;
var myEntry = {};
var myList = [];
for (var i = 0; i < responseLength; i++) {
myEntry.status = response[i].status;
myEntry.createdAt = response[i].createdAt;
myEntry.serviceName = response[i].rel_ServiceEval_Service.serviceName;
myEntry.supplierId = response[i].rel_ServiceEval_Service.supplierId;
myList.push(myEntry);
}
cb(null, myList);
});
};

这样做的结果是远程方法似乎找不到rel_ServiceEval_Service中的字段。

{
"list": [
{
"status": "Draft",
"createdAt": "2018-09-04T06:20:40.889Z"
}, ...

我已经在客户端的服务中平展返回值，但这在 Dev 中只是一个临时解决方案。 有关如何在远程方法中执行此操作的任何指导？

Answer 1

你需要使用 .toJSON(( 来序列化返回的数据：

ServiceEvaluation.evaluationList = function(cb) {
ServiceEvaluation.find({
fields: {
status: true,
createdAt: true,
serviceId: true
},
include: {
relation: 'rel_ServiceEval_Service',
scope: {
fields: {
serviceName: true,
supplierId: true
}
}
}
}, function(err, response) {
var myEntry = {};
var myList = [];
async.map(response, function(singleItem,callback){
serializedSingleItem = singleItem.toJSON()
var myEntry = {status: serializedSingleItem.status, createdAt: serializedSingleItem.createdAt, serviceName: serializedSingleItem["rel_ServiceEval_Service"]["serviceName"], supplierId: serializedSingleItem["rel_ServiceEval_Service"]["supplierId"]}
callback(null, myEntry)
}, function(err, myList){
cb(null, myList)
})
});
};