BDLJsonPathHelper

Genero BDL JSON Path Helper with examples

Getting Started

Prerequisite
Before you get started, you will need to make sure you download the Java prerequisites
which includes JsonPath ( https://github.com/json-path/JsonPath ) and all of its dependencies.

You can download the latest version of JsonPath with all the dependencies here: https://jar-download.com/artifacts/com.jayway.jsonpath

Building the Jar File

Once you have all the dependencies downloaded and added to your CLASSPATH, you can build the
jar file using the jar-build.sh build script. The script is written in bash, if you are on
Windows you will need to build it manually.

./jar-build.sh

Install the jar file and add it to your class path

Using BDLJsonPath in BDL

Genero Implementation

IMPORT util
IMPORT JAVA com.fourjs.jsonhelper.BDLJsonPath
IMPORT JAVA java.lang.String

PUBLIC TYPE BDLJsonPath com.fourjs.jsonhelper.BDLJsonPath
PUBLIC TYPE JavaString java.lang.String
PUBLIC TYPE JavaStringArray ARRAY[] OF JavaString

MAIN
   DEFINE jsonPath BDLJsonPath
   DEFINE jsonString STRING
   DEFINE resultString STRING
   DEFINE resultList JavaStringArray
   DEFINE idx INTEGER
   DEFINE jsonObj util.JSONObject
   DEFINE jsonArray util.JSONArray

   LET jsonString = getExampleJson()
   LET jsonPath = BDLJsonPath.create(jsonString)

   LET resultString = jsonPath.getResult("$.store.book[0].author") 
   DISPLAY SFMT("Result is %1", resultString)

   LET resultList = jsonPath.getResultList("$.store.book[*].author")
   FOR idx = 1 TO resultList.getLength()
      DISPLAY SFMT("Result from list[%1] is %2", idx, resultList[idx])
   END FOR

   DISPLAY "Complex JSON Object"
   LET resultString = jsonPath.getResultJson("$.store")
   LET jsonObj = util.JSONObject.parse(resultString)
   DISPLAY util.JSON.format(jsonObj.toString())

   DISPLAY "JSON Array"
   LET resultString = jsonPath.getResultJson("$.store.book[*]")
   LET jsonArray = util.JSONArray.parse(resultString)
   DISPLAY util.JSON.format(jsonArray.toString())

   DISPLAY "Simple JSON Object"
   LET resultString = jsonPath.getResultJson("$.store.bicycle")
   LET jsonObj = util.JSONObject.parse(resultString)
   DISPLAY util.JSON.format(jsonObj.toString())

END MAIN

See the example.4gl in the repo for a full example

References

Make sure you review the JsonPath documentation in order to fully to understand all the
predicates that are supported in the JsonPath.

https://github.com/json-path/JsonPath