JSON Path Transformer

Discover more about the JSON Path Transformer component and how to use it on the Digibee Integration Platform.

JSON Path Transformer has the function of receiving a JSON object and making filters and data extractions from an expression.

JSONPath is a consulting language for JSON with resources similar to XPath. This expression is normally used to select and extract property values from a JSON object. Learn more in the documentation about JSONPath.

Parameters

Take a look at the configuration options for the component. Parameters supported by Double Braces expressions are marked with (DB).

Parameter	Description	Default value	Data type
JSON Path	Used to show which expression will be used when processing JSON. It's a mandatory parameter and must be configured according to what you want to process.	$.store.books[?(@.title=='IT')]	String
Fail On Error	If the option is activated, the execution of the pipeline with an error will be interrupted; otherwise, the pipeline execution proceeds, but the result will show a false value for the “success” property.	False	Boolean

See a list of options for declaring JSONPath:

• $: object root or vector.

• .property: selects a specific property in the related object.

• ['property']: selects a specific object in the related object. Use single quotes only around the property name. Tip: keep this instruction in mind if the property name has special characters, such as spaces, or if it starts with characters different than A..Za..z_.

• [n]: selects the n element of a vector. The indexes start with 0.

• [index1,index2,…]: selects elements from the vector with specific indexes and returns a list.

• ..property: descending recursive. It makes a descending search in property names and returns a vector of all the values with this property name. It always returns a list, even if only 1 property is found.

• *: the asterisk selects all the elements in an object or vector, whatever their names or indexes are. For example, “address.*” means all the properties of the object address, while “book[*]” means all the items of a book vector.

• [input:output] / [input:]: selects elements from an input vector and even, but not necessarily, an output vector. If the output is omitted, select all the vectors until the end of the vector. A list is returned.

• [:n]: selects the first n elements of the vector. A list is returned.

• [-n:]: selects the last n elements of the vector. A list is returned.

• [?(expression)]: filter expression. It selects all the elements in an object or vector that match with the specified filter. A list is returned.

• [(expression)]: script expressions can replace explicit names from properties or indexes. For example, [(@.size-1)], that selects the last items of a vector. Here, the size refers to the vector size in question more than a JSON file named "size".

• @: used in filter expressions to make reference to the current joint that is being processed.

• ==: equal to .1 and '1' are considered the same result. String values must be attached in single quotes (and not in double quotes): [?(@.cor=='vermelho')].

• !=: different than. String values must be attached in single quotes.

• >: greater than.

• >=: greater than or equal to.

• <: smaller than.

• <=: smaller than or equal to.

• =~: compatible with a regular RedEx Java Script. For example, [?(@.description =~ /cat.*/i)] matches items whose description starts with cat (upper and lowercase aren't considered).

• !: used to deny a filter. For example, [?([email protected])] matches items that don't have the isbn property.

• &&: AND logical operator. Example: [?(@.category=='fiction' && @.price < 10)]

• ||: OR logical operator. Example: [?(@.category=='fiction' || @.price < 10)]

Messages flow

Input

To show the functionality of this component, you must configure an input JSON in a pipeline with JSON Path Transformer. After adding it to the pipeline, it's necessary to configure the JSONPath expression as $.address..[?(@.postalCode == '02375')].streetAddress or the example won't work.

The intention of this example is to filter the input addresses by one postal code only and return just the address street. See:

{
  "address": [
      {
          "streetAddress": "Bogisich Terrace",
          "city": "New Napoleonville",
          "postalCode": "02375"
},
      {
          "streetAddress": "Schuster Spring",
          "city": "Lake Loraineborough",
          "postalCode": "68244"
      },
      {
          "streetAddress": "Hettinger Ports",
          "city": "Dorcaschester",
          "postalCode": "86760"
      },
      {
          "streetAddress": "Rippin Mount",
          "city": "Lake Bernadettetown",
          "postalCode": "57163"
      },
      {
          "streetAddress": "Gutmann Village",
          "city": "West Darlene",
          "postalCode": "00064"
      }
  ]
}

Output

The structure will be the JSON filtered by the JSONPath specification.

[  
   "Bogisich Terrace"
]

JSON Path Transformer in action

Below you can see how the component responds to certain situations and how it is configured in each case.

Return the book authors only with a recursive descendant parser

In this example, you'll see only the authors of an array with books inside a store. The expression configuration of the component must be $..author.

Input

{
  "store": {
      "book": [
          {
              "category": "reference",
             "author": "Nigel Rees",
              "title": "Sayings of the Century",
              "price": 8.95
      },
          {
              "category": "fiction",
              "author": "Evelyn Waugh",
              "title": "Sword of Honour",
              "price": 12.99
},
 {
  "category": "fiction",
  "author": "Herman Melville",
  "title": "Moby Dick",
  "isbn": "0-553-21311-3",
  "price": 8.99
 },
  {
 "category": "fiction",
 "author": "J. R. R. Tolkien",
 "title": "The Lord of the Rings",
 "isbn": "0-395-19395-8",
 "price": 22.99
         }
  ],
"bicycle": {
"color": "red",
"price": 19.95
 }
}
}

Output

[
  "Nigel Rees",
  "Evelyn Waugh",
  "Herman Melville",
  "J. R. R. Tolkien"
]
[
  "Nigel Rees",
  "Evelyn Waugh",
  "Herman Melville",
  "J. R. R. Tolkien"
]

Return products with a value lower than the one specified only

In this example, you'll see only the products of an array with prices lower than US$3,300. The expression configuration of the component must be $..[?(@.price<3300)].

Input

{
  "data": [
      {
          "product": "Samsung 4k Q60T 55",
          "price": 3278.99
      },
      {
          "product": "Samsung galaxy S20 128GB",
          "price": 3698.99
      }
  ]
}
​

Output

[
  {
      "product": "Samsung 4k Q60T 55",
      "price": 3278.99
  }
]

Informing an invalid expression with the "Fail On Error: false" configuration

With this example you can configure the component with Fail On Error as “false” and use the expression $.

With these configurations, the result will be an error message and with the property "success": false.

Input

{
  "data": [
      {
          "product": "Samsung 4k Q60T 55",
          "price": 3278.99
      },
      {
          "product": "Samsung galaxy S20 128GB",
          "price": 3698.99
      }
  ]
}

Output

{
  "success": false,
  "error": "The Json Path transformation has failed. Please check your specification: $.",
  "exception": "com.jayway.jsonpath.InvalidPathException: Path must not end with a '.' or '..'"
}

Informing an invalid expression with the "Fail On Error: true" configuration

With this example you can configure the component with Fail On Error as “true” and use the expression $.

With these configurations, the result will be an error message and the deployment will be immediately interrupted.

Input

{
  "data": [
      {
          "product": "Samsung 4k Q60T 55",
          "price": 3278.99
      },
      {
          "product": "Samsung galaxy S20 128GB",
          "price": 3698.99
      }
  ]
}

Output

{
  "timestamp": 1603900161240,
  "error": "Json Path Transformer has failed",
  "code": 500
}