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Transform JSON

Provides examples on transforming JSON object within Siddhi.

For all functions available to transform JSON see Siddhi Execution JSON.

define stream InputStream(jsonString string);

from InputStream 
select json:toObject(jsonString) as jsonObj 
insert into PersonalDetails;

from PersonalDetails
select jsonObj, 
    json:getString(jsonObj,'$.name') as name,
    json:isExists(jsonObj, '$.salary') as isSalaryAvailable,
    json:toString(jsonObj) as jsonString 
insert into OutputStream;

from OutputStream[isSalaryAvailable == false]
select 
    json:setElement(jsonObj, '$', 0f, 'salary') as jsonObj
insert into PreprocessedStream;

define stream InputStream(jsonString string);
from InputStream
select json:toObject(jsonString) as jsonObj	Transforms JSON string to JSON object which can then be manipulated
insert into PersonalDetails;
from PersonalDetails select jsonObj,
json:getString(jsonObj,'$.name') as name,	Get the name element(string) form the JSON
json:isExists(jsonObj, '$.salary') as isSalaryAvailable,	Validate if salary element is available
json:toString(jsonObj) as jsonString	Stringify the JSON object
insert into OutputStream;
from OutputStream[isSalaryAvailable == false] select
json:setElement(jsonObj, '$', 0f, 'salary') as jsonObj	Set salary element to 0 is not available
insert into PreprocessedStream;

Input

Below event is sent to InputStream,

[

{
    "name" : "siddhi.user",
    "address" : {
        "country": "Sri Lanka",
    },
    "contact": "+9xxxxxxxx"
}

]

Output

After processing, the following events will be arriving:

• OutputStream:
  [ {"address":{"country":"Sri Lanka"},"contact":"+9xxxxxxxx","name":"siddhi.user"}, siddhi.user, false,
  "{\"name\" : \"siddhi.user\", \"address\" : { \"country\": \"Sri Lanka\", }, \"contact\": \"+9xxxxxxxx\"}"]

• PreprocessedStream:
  [

  {
      "name" : "siddhi.user",
      "salary": 0.0
      "address" : {
          "country": "Sri Lanka",
      },
      "contact": "+9xxxxxxxx"
  }
  

  ]

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