JsonGetProp is an OCL operator for you to read a named property from a JSON string, including properties inside nested JSON objects.
Syntax
jsonString.JsonGetProp('propertyName')
| Part | Meaning |
|---|---|
jsonString
|
The JSON string that contains the property you want to read. |
'propertyName'
|
The name of the JSON property to retrieve. |
Return value
JsonGetProp returns the value of the requested JSON property as a string.
If the property is unavailable, the operator returns null. Account for this result before using the returned value in later OCL expressions.
Read a top-level property
Use JsonGetProp with the name of a property at the top level of the JSON string.
'{name: "Samuel"}'.JsonGetProp('name')
The expression returns:
'Samuel'
Read a nested property
You can chain JsonGetProp calls when one property contains another JSON object. The first call retrieves the nested object; the next call retrieves a property from that object.
'{person: {name: "Samuel", age: 25}}'.JsonGetProp('person').JsonGetProp('age')
The expression returns the value of age:
25
In this example, JsonGetProp('person') retrieves the person object and JsonGetProp('age') retrieves its age property.
A property name must be available in the JSON value passed to the operator. For example, this expression returns null because email is not present:
'{name: "Samuel"}'.JsonGetProp('email')
Use with ViewModel JSON
If you need JSON generated from a ViewModel, use ViewModelAsJSon. You can then use JsonGetProp to read a property from the resulting JSON string. Presentation names configured on ViewModel attributes affect the JSON node names generated by ViewModelAsJSon.