ON THIS PAGE IsJson() tests whether a specified string contains valid JSON (JavaScript Object Notation) data. You can also validate a specific JSON data type.
Syntax:
value IsJson(json [, type])
Return data type:
Arguments
json
String to test. It can contain extra spaces or newlines.
type
Optional argument that specifies the JSON data type to test for.
'value' (default)
'object'
'array'
'string'
'number'
'Boolean'
'null'
Example: Valid and invalid chart expressions
IsJson( 'null' )
Returns -1 (true)
IsJson( '"abc"', 'value' )
Returns -1 (true)
IsJson( '"abc"', 'string' )
Returns -1 (true)
IsJson( 123, 'number' )
Returns -1 (true)
IsJson( 'text' )
Returns 0 (false) , 'text' is not a valid JSON value
IsJson( '"text"', 'number' )
Returns 0 (false) , '"text"' is not a valid JSON number
IsJson( '"text"', 'text' )
Returns 0 (false) , 'text' is not a valid JSON type
Example - IsJson fundamentals
Chart expression
Overview
Open the Data load editor and add the load script below to a new tab.
The load script contains:
A dataset which is loaded into a data table called Example .
One field in the data table called API_Response .
A derived field called ID . This field uses the Rec() function to enumerate the input records.
Load script
Example:
Load
Recno() AS ID, API_Response
inline [
API_Response
'{"id": 1, "name": "Alice"}'
'{"id": 2, "name": "Bob"}'
'{invalid json string}'
'{"id": 4, "name": "Charlie"}'
'{"id": 5, name: "David"}'
];Results
Load the data and open a sheet. Create a new table and add these fields as dimensions:
Create the following calculated dimension:
Results table
ID
API_Response
IsJson(API_Response)
1
{"id": 1, "name": "Alice"}
-1 (true)
2
{"id": 2, "name": "Bob"}
-1 (true)
3
{invalid json string}
0 (false)
4
{"id": 4, "name": "Charlie"}
-1 (true)
5
{"id": 5, name: "David"}
0 (false)
The output returns -1 , or true , for those values with valid JSON syntax.
The output returns 0 , or false , for the following ID records (3 and 5 ) with invalid JSON:
{invalid json string} —The text string does not represent a valid JSON response structure.
{"id": 5, name: "David"} —The second key-value pair is missing quotation marks around the key "name" .
Example - IsJson scenario
Chart expression
Overview
Open the Data load editor and add the load script below to a new tab.
The load script contains:
Load script
Example:
Load *
INLINE [OrderDetails
'{ "order_id": "12345", "customer": { "name": "John Doe", "email": "john.doe@example.com"}, "items": {"product": "Laptop", "quantity": 2, "price": 1200 }, "total_price": 2400 }'
];Results
Load the data and open a sheet. Create a new table and add this field as a dimension:
Create the following measures:
IsJson( OrderDetails) , to calculate if the values in OrderDetails are valid JSON.
IsJson( JsonGet ( OrderDetails, '/items/price' ), 'number' ) , using the function JsonGet , it retrieves the JSON text for the price key and validates that the value of price is a number.
Results table
OrderDetails
IsJson(OrderDetails)
IsJson( JsonGet ( OrderDetails, '/items/price' ), 'number' )
{ "order_id": "12345", "customer": { "name": "John Doe", "email": "john.doe@example.com"}, "items": {"product": "Laptop", "quantity": 2, "price": 1200 }, "total_price": 2400 }
-1 (true)
-1 (true)
The first measure returns -1 (true) because OrderDetails contains valid JSON syntax.
The second measure returns -1 (true) because the value of the price key is a valid number, 1200 .
See also:
