We are currently investigating JSON as a potential API data transfer language for our system and a question about using JSON Reference came up.
Consider the following example:
{
"invoice-address" : { "street": "John Street", "zip": "12345", "city": "Someville" },
"shipping-address": { "$ref": "#/invoice-address" }
}
According to our research, this is a valid usage of JSON Reference. We replace the instance of an object with another object containing the reference pointing to a different object using a JSON Pointer fragment.
Now, a JSON Reference always consists of a key-value pair and thus has to be enclosed in an object. This would mean that in order to reference a non-object data type (e.g. the zip and city strings in the example above) you would have to do the following:
{
"invoice-address" : { "street": "John Street", "zip": "12345", "city": "Someville" },
"shipping-address": { "street": "Doe Street", "zip": { "$ref": "#/invoice-address/zip" }, "city": { "$ref": "#/invoice-address/city" } }
}
Even though the JSON Pointers now correctly point to string values, we had to change the data type of zip and city from string to object, which make them fail validation against our JSON Schema, because it declares them as strings.
However, the JSON Reference draft states:
Implementations MAY choose to replace the reference with the referenced value.
Does that mean that we are allowed to "preprocess" the file and replace the JSON Reference object with the resolved string value before validating against the JSON Schema? Or are references limited to object types only?
Thanks to anyone who can shed some light onto this.
I wouldn't expect most validators to resolve JSON References before validation. You could either:
resolve JSON References before validation
adapt the JSON Schemas to allow for JSON Reference objects in certain places
Personally, I think the first option is much neater.
You could end up with circular references I suppose - I don't know which validator/language you're using, but tv4 can definitely handle it.
Related
Can we write json key with space like first name?
Below is the sample json:
[
{
"first_name": "James"
},
{
"first_name": "Tom"
}
]
Yes, you can, it is valid RFC 8259, however it will make more difficult to use in some languages, for example in PHP you want be able to use the arrow operator to access the data.
This obviously won't make this JSON not valid.
Here is the desired schema and json for illustration purpose. Please see the link below.
JSON Schema and JSON
{
"id": "123" ,
"ts": "1234567890",
"complex_rules":
[
{
"type":"admin",
"rule":{
"rights":"all",
"remarks": "some admin remarks"
}
},
{
"type":"guest",
"rights": "limited"
},
{
"type":"anonymous",
"rights": "blocked"
}
]
}
The 'complex_rules' is an array of json object:
With type either be a : "admin", "guest", "anonymous" and the 'type' attribute is MANDATORY.
Each object in array can have its own structure, but the type can be either of: "admin", "guest", "anonymous" only. No other type attribute is acceptable.
The conditions to evaluate:
The type of object in the array cannot re-occur in the array. (I know this seems to be not possible, so we can ignore this)
If attribute "rights" in the {type=admin object} with any value, then we cannot have "rights": "limited" or any value in {type=guest object}. The JSON Schema validation must complain about this.
Another twist, either object {type":"guest"}or {type":"anonymous"} can exist. Both types cannot coexist along with other types.
----Update
The above link is the solution this question.
In regards to 1 and 2:
You need to use a combination of if, then, and not keywords to construct the logic you require with the correct level of applicability.
In regards to 3:
The type of object in the array cannot re-occur in the array. (I know
this seems to be not possible, so we can ignore this)
Right, that's correct, it's not possible as of draft-7 JSON Schema.
I'm new to Go and working hard to follow its style and I'm not sure how to proceed.
I want to push a JSON object to a Geckoboard leaderboard, which I believe requires the following format based on the API doc and the one for leaderboards specifically:
{
"api_key": "222f66ab58130a8ece8ccd7be57f12e2",
"data": {
"item": [
{ "label": "Bob", "value": 4, "previous_value": 6 },
{ "label": "Alice", "value": 3, "previous_value": 4 }
]
}
}
My instinct is to build a struct for the API call itself and another called Contestants, which will be nested under item. In order to use json.Marshall(Contestant1), the naming convention of my variables would not meet fmt's expectations:
// Contestant structure to nest into the API call
type Contestant struct {
label string
value int8
previous_rank int8
}
This feels incorrect. How should I configure my Contestant objects and be able to marshall them into JSON without breaking convention?
To output a proper JSON object from a structure, you have to export the fields of this structure. To do it, just capitalize the first letter of the field.
Then you can add some kind of annotations, to tell your program how to name your JSON fields :
type Contestant struct {
Label string `json:"label"`
Value int8 `json:"value"`
PreviousRank int8 `json:"previous_rank"`
}
I am trying to process a Json data in Java. I have the data in below format (it is nested data structure with arrays etc.)
person.name,person.friend[0],person.friend[1],person.address.city,person.address.country
1,x,y,kolkata,india
2,a,b,london,uk
The first line is header denoting the nested object hierarchy. I want a json in below format,
{
"data" : [
{
"name" : "1",
"friend" : ["x","y"],
"address" : { "city" : "kolkata", "country" : "india" }
},
{
"name" : "2",
"friend" : ["a","b"],
"address" : { "city" : "london", "country" : "uk" }
} ]
}
The object structure is dynamic and I dont know the columns or header in advance, i.e. I can not use any predefined POJO to get populated with the data. In this example, it "Person" object but it may be any object structure.
I have gone through Jackson or Gson API, but none seems to fulfill this requirement. Is there any API that can help? or any other wayout?
Thanks
You need to do it in 2 steps.
First, you have to parse your CSV. I recommend superCSV. Parsing CSV may be fancy sometimes, so I really recommend you to use a library for that.
Second, you can serialize into JSON. Then you can use GSON, jackson, flexjson, whatever.
After a long Google...I found that the only option is to represent a collection based object structure in flat file is repeated rows,
person.name,person.friends,person.address.city,person.address.country
1,x,kolkata,india
1,y,kolkata,india
2,a,london,uk
2,b,london,uk
where the non-array elements repeats. We need to form a json from this, then need to filter or club the same object by its ID (here person.name)
For some endpoints SimpleGeo.com returns something like this:
{
"geometry":{
"type":"Point",
"coordinates":[
-122.421583,
37.795027
]
},
"type":"Feature",
"id":SG_5JkVsYK82eLj26eomFrI7S_37.795027_-122.421583#1291796505,
"properties":{
"province":"CA",
"city":"San Francisco",
"name":"Bell Tower",
"tags":[],
"country":"US",
"phone":"+1 415 567 9596",
"href": http://api.simplegeo.com/1.0/features/SG_5JkVsYK82eLj26eomFrI7S_37.795027_-122.421583#1291796505.json,
"address":"1900 Polk St",
"owner":"simplegeo",
"postcode":"94109",
"classifiers":[
{
"category":"Restaurant",
"type":"Food & Drink",
"subcategory":""
}
]
}
}
(see http://simplegeo.com/docs/api-endpoints/simplegeo-features#get-detailed-information).
Now I have a small problem deserializing the 'properties' part. If I use e.g. a type of Dictionary it converts it to a nice dictionary, but the 'classifiers' value is just one {} string.
Is there any way to tell json.net to deserialize sub-arrays into yet another Dictionary etc etc? Basically there's an amount of plain key/values in that return, but I do know that there might be more than just that 'classifiers' sub-array (see the 'tags'), and maybe the depth goes even further in the values...
So basically what I was wondering is, how do I properly deserialize the properties part? Any suggestions? I don't mind writing my own JsonConverter, but maybe there is already a way that works without it.
I've found a solution for a similar question over here:
Json.NET: Deserializing nested dictionaries.
It uses a custom JsonConverter and I don't see a way to do without it.