JSON String, Extract Value using JSON-Path

// GraalJS Script (engine type: 2)

/*
Notes:
- JSONPath is a query language for JSON, similar to XPath for XML.
    - A JSONPath expression specifies a path to an element (or a set of elements) in a JSON.
    - Paths can use the dot notation: "$.store.book[0].title" or "$['store']['book'][0]['title']"
- JSON is an abbreviation for "JavaScript Object Notation" and a widely used data exchange format.
- Assuming an element set, specify a multiline string type to store extracted value.
- In getting as a number data, numeric parsing depends on JavaScript parseFloat().
    - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseFloat
- If the path to the object or array is configured, the value cannot be obtained.
    - Output Sample: "[object Object],[object Object]"
- JSON PATH Online Evaluator
    - http://jsonpath.com/
- Example1
    - { "id": "8PT59XXXXX68743YYYYYCATA", "resource": { "id": "2DC87XXXXX52041YY" } }
    - Config PATH: "$.resource.id"
    - Return Value: "2DC87XXXXX52041YY"
- Example2
      {
        "etag": "abcdefgh",
        "members": [{
          "etag": "ijklmnop",
          "email": "example1@example.com"
        },
        {
          "etag": "qrstuvwx",
          "email": "example2@example.com"
        }]
      }
    - Config PATH: "$.members[*].email"
    - Return Value (required Multiline String pocket):
      example1@example.com
      example2@example.com

Notes(ja):
- JSONPath とは XPath に似た JSON データ用のクエリ言語です。
    - JSONPath 式は、JSON データ内の要素（または要素セット）へのパスを指定します。
    - ドット表記等で設定されます: "$.store.book[0].title" or "$['store']['book'][0]['title']"
- JSON とは "JavaScript Object Notation" の略です。広く普及しているデータ交換フォーマットです。
- 要素セットが想定される場合、格納先には複数行文字列型のデータ項目を指定してください。
- 数値として取得したい（数値型データ項目を指定した）場合、JavaScript parseFloat() で解釈されます。
    - https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Global_Objects/parseFloat
- オブジェクトや配列へのパスが設定された場合、値（Value）は取得できません。
    - 取得例： "[object Object],[object Object]"
*/


/*
APPENDIX
- https://goessner.net/articles/JsonPath/index.html#e2
    - $
    - the root object/element
    - @
    - the current object/element
    - . or []
    - child operator
    - ..
    - recursive descent. JSONPath borrows this syntax from E4X.
    - *
    - wildcard. All objects/elements regardless their names.
    - []
    - subscript operator.
    - XPath uses it to iterate over element collections and for predicates.
    - In Javascript and JSON it is the native array operator.
    - [,]
    - Union operator in XPath results in a combination of node sets.
    - JSONPath allows alternate names or array indices as a set.
    - [start:end:step]
    - array slice operator borrowed from ES4.
    - ?()
    - applies a filter (script) expression.
    - ()
    - script expression, using the underlying script engine.
*/

//////// START "main()" /////////////////////////////////////////////////////////////////
main();
function main(){ 

//// == Config Retrieving / 工程コンフィグの参照 ==
const strJsonText      = configs.get( "StrConfA" ); // required
  if( strJsonText    === "" ){
    throw new Error( "\n AutomatedTask ConfigError:" +
                     " Config {A JsonText} is empty \n" );
  }
const strJsonPath      = configs.get( "StrConfB" ); // required
  if( strJsonPath    === "" ){
    throw new Error( "\n AutomatedTask ConfigError:" +
                     " Config {B JsonPath} is empty \n" );
  }
const multiPocketJsonValue = configs.getObject( "SelectConfC" ); // required


//// == Data Retrieving / ワークフローデータの参照 ==
// (Nothing. Retrieved via Expression Language in Config Retrieving)


//// == Calculating / 演算 ==
const objJsonText   = JSON.parse( strJsonText );
const arrJsonValues = jsonPath( objJsonText, strJsonPath );
engine.log( " AutomatedTask: # of JsonValues: " + arrJsonValues.length );

let strJsonValues  = "";
for( let i = 0; i < arrJsonValues.length; i++ ){
  strJsonValues   += arrJsonValues[i].toString();
  if( i !== arrJsonValues.length - 1 ){
    strJsonValues += "\n";
  }
}
let numJsonValue   = parseFloat( strJsonValues );


//// == Data Updating / ワークフローデータへの代入 ==
if( multiPocketJsonValue.matchDataType( "STRING" ) ){
  engine.log( " AutomatedTask: Pocket for JsonValue is STRING type" );
  engine.setData( multiPocketJsonValue, strJsonValues );
}else{
  engine.log( " AutomatedTask: Pocket for JsonValue is NUMERIC type" );
  engine.setData( multiPocketJsonValue, new java.math.BigDecimal( numJsonValue ) );
}

} //////// END "main()" /////////////////////////////////////////////////////////////////



////////// (source) https://code.google.com/archive/p/jsonpath/downloads
/* JSONPath 0.8.0 - XPath for JSON
 *
 * Copyright (c) 2007 Stefan Goessner (goessner.net)
 * Licensed under the MIT (MIT-LICENSE.txt) licence.
 */
function jsonPath(obj, expr, arg) {
  var P = {
    resultType: arg && arg.resultType || "VALUE",
    result: [],
    normalize: function(expr) {
      var subx = [];
      return expr.replace(/[\['](\??\(.*?\))[\]']/g, 
                          function($0,$1){return "[#"+(subx.push($1)-1)+"]";})
                 .replace(/'?\.'?|\['?/g, ";")
                 .replace(/;;;|;;/g, ";..;")
                 .replace(/;$|'?\]|'$/g, "")
                 .replace(/#([0-9]+)/g, function($0,$1){return subx[$1];});
    },
    asPath: function(path) {
      var x = path.split(";"), p = "$";
      for (var i=1,n=x.length; i<n; i++)
         p += /^[0-9*]+$/.test(x[i]) ? ("["+x[i]+"]") : ("['"+x[i]+"']");
      return p;
    },
    store: function(p, v) {
      if (p) P.result[P.result.length] = P.resultType == "PATH" ? P.asPath(p) : v;
      return !!p;
    },
    trace: function(expr, val, path) {
      if (expr) {
        var x = expr.split(";"), loc = x.shift();
        x = x.join(";");
        if (val && val.hasOwnProperty(loc))
          P.trace(x, val[loc], path + ";" + loc);
        else if (loc === "*")
          P.walk(loc, x, val, path, function(m,l,x,v,p) { P.trace(m+";"+x,v,p); });
        else if (loc === "..") {
          P.trace(x, val, path);
          P.walk(loc, x, val, path,
                 function(m,l,x,v,p) {
                   typeof v[m] === "object" && P.trace("..;"+x,v[m],p+";"+m);
                 }
          );
        }
        else if (/,/.test(loc)) { // [name1,name2,...]
          for (var s=loc.split(/'?,'?/),i=0,n=s.length; i<n; i++)
            P.trace(s[i]+";"+x, val, path);
        }
        else if (/^\(.*?\)$/.test(loc)) // [(expr)]
          P.trace(P.eval(loc, val, path.substr(path.lastIndexOf(";")+1))+";"+x, val, path);
        else if (/^\?\(.*?\)$/.test(loc)) // [?(expr)]
          P.walk(loc, x, val, path, 
             function(m,l,x,v,p) {
               if (P.eval(l.replace(/^\?\((.*?)\)$/,"$1"),v[m],m)) P.trace(m+";"+x,v,p);
             }
          );
        else if (/^(-?[0-9]*):(-?[0-9]*):?([0-9]*)$/.test(loc))
          // [start:end:step]  phyton slice syntax
          P.slice(loc, x, val, path);
      }
      else
        P.store(path, val);
    },
    walk: function(loc, expr, val, path, f) {
      if (val instanceof Array) {
        for (var i=0,n=val.length; i<n; i++)
          if (i in val)
            f(i,loc,expr,val,path);
      }
      else if (typeof val === "object") {
        for (var m in val)
          if (val.hasOwnProperty(m))
            f(m,loc,expr,val,path);
      }
    },
    slice: function(loc, expr, val, path) {
      if (val instanceof Array) {
        var len=val.length, start=0, end=len, step=1;
        loc.replace(/^(-?[0-9]*):(-?[0-9]*):?(-?[0-9]*)$/g,
            function($0,$1,$2,$3){
              start=parseInt($1||start);end=parseInt($2||end);step=parseInt($3||step);
            });
        start = (start < 0) ? Math.max(0,start+len) : Math.min(len,start);
        end   = (end < 0)   ? Math.max(0,end+len)   : Math.min(len,end);
        for (var i=start; i<end; i+=step)
           P.trace(i+";"+expr, val, path);
      }
    },
    eval: function(x, _v, _vname) {
      try { return $ && _v && eval(x.replace(/@/g, "_v")); }
      catch(e) { throw new SyntaxError("jsonPath: " + e.message + ": " +
                 x.replace(/@/g, "_v").replace(/\^/g, "_a")); }
    }
  };
  var $ = obj;
  if (expr && obj && (P.resultType == "VALUE" || P.resultType == "PATH")) {
    P.trace(P.normalize(expr).replace(/^\$;/,""), obj, "$");
    return P.result.length ? P.result : false;
  }
} 
/// JSONPath end