Golang find a value from a map of nested json data from MongoDB - mongodb

Question

I am trying to receive data from my MongoDB using MGO in a map of type []map[string]interface{}
My JSON looks like this -
{
"_id":"string",
"brandId":123,
"category":{
"television":[
{
"cat":"T1",
"subCategory":[
{
"subCat":"T1A TV",
"warrantyPeriod":6
}
],
"warrantyPeriod":12
},
{
"cat":"T2",
"subCategory":[
{
"subCat":"T2A",
"warrantyPeriod":18
},
{
"subCat":"T2B",
"warrantyPeriod":9
}
],
"warrantyPeriod":15
},
{
"cat":"T3",
"subCategory":[
{
"subCat":"T3A",
"warrantyPeriod":3
},
{
"subCat":"T3B",
"warrantyPeriod":5
},
{
"subCat":"T3C",
"warrantyPeriod":7
},
{
"subCat":"T3D",
"warrantyPeriod":11
}
],
"warrantyPeriod":4
}
],
"television_warrantyPeriod":24
},
"title":"BrandName"
}
I would ideally pass in the category name i.e. 'television' and cat and subCat values which could be optional.
For e.g. something like this -
{
"categorySlug": "television",
"brandId": "123",
"model": "T2"
}
In which case I would expect to find '15' which is the warrantyPeriod value for T2 if there are no T2A or T2B specified.
My query functions look like this -
var data map[string]string
err := json.NewDecoder(r.Body).Decode(&data)
log.Println(err)
var buffer bytes.Buffer
buffer.WriteString("category.")
buffer.WriteString(data["categorySlug"])
brandId, _ := strconv.Atoi(data["brandId"])
concernedbrandandcategory := database.GetMappedFields("Brands", bson.M{"brandId": brandId, buffer.String(): bson.M{"$exists": true}}, bson.M{buffer.String(): 1})
categorymap := concernedbrandandcategory[0]
log.Println(categorymap["category"]["television"], reflect.TypeOf(categorymap))
My GetMappedFields function looks like this -
func GetMappedFields(collectionName string, query interface{}, selector interface{}) (result []map[string]interface{}) {
MgoSession.DB(Dbname).C(collectionName).Find(query).Select(selector).All(&result)
return
}
I'm just not able to wrap my head around this nested structure which sometimes returns a map and sometimes an interface!
Any help would be highly appreciated!

Answer 1

you can do something like this
majorCat := body["categorySlug"]
category := body["category"]
subCategory := body["subCategory"]
brandId, err := strconv.Atoi(body["brandId"])
if err != nil {
log.Println(err)
}
result := database.GetMappedFields("Brands", bson.M{"brandId": brandId}, bson.M{"category": 1, "_id": 0})
internalObj := result[0]["category"].(map[string]interface{})
finalValue := internalObj["television_warrantyPeriod"]
if category != "" {
for _, v := range internalObj[majorCat].([]interface{}) {
subObj := v.(map[string]interface{})
if subObj["cat"] == category {
finalValue = subObj["warrantyPeriod"]
if subCategory != "" {
minorObj := subObj["subCategory"].([]interface{})
for _, iter := range minorObj {
kevVal := iter.(map[string]interface{})
if kevVal["subCat"] == subCategory {
finalValue = kevVal["warrantyPeriod"]
}
}
}
}
}
}
Hopefully this will do dynamically or you can create a struct so that it can directly be decoded into that cheers