A simple NPM package to get boundary indexes from JSON string or normal string easily and faster.

What is Boundary

Here boundary indecates spacial area which need to track. Generally in JSON string there may have Objects, Arrays or internal strings. If we need to track their start or end indexes, we can use JB [Json Boundary ]

When we need this

• When we work with json string we may need to apply regex on it. but we don't want to capture anything from a boundary area who has a special starting & ending char. Then we can get their indexes , can do more complex operation and can apply regex with own logic easily.
• We can find how many strings, objects , arrays or boundaries in our string and can find their size form the start & end indexes.
• When we need to simplify our complex json string .

Installation

npm install json-boundary

Implementation

import { JsonBoundary } from "json-boundary";
const JB = new JsonBoundary();

const string = `(string= !"(a='4' && b=6)") && id=50 && tag = [["abc\'d","(xyz)"],{'abc':true},1,2]`;
console.log(JB.getBoundaries(string)); 

// output: [ { start: 10, end: 25 }, { start: 46, end: 81 } ]

/************************************************************** get simple version of our string */
const { str: simpleVersion, id } = JB.getSimple(string, "###");
console.log(simpleVersion);

// output: (string= !###) && id=50 && tag = ###

/************************************************************** now easily apply regex or any other operation to our simple string */
const modified = simpleVersion.replace(
  /(string)(=)(.+###)/g,
  (m, g1, g2, g3) => {
    return `"${g1}":{"equals":${g3.trim()}}`; // replace match with "string":{"equals":!###}"
  }
);
console.log(JB.replaceOriginal(modified, id)); 

// output: ("string":{"equals":!"(a='4' && b=6)") && id=50 && tag = [["abc'd","(xyz)"],{'abc':true},1,2]}

Explanation

Here default setup is: 
setup={
  mileStones: "!:=@<->^?*$#",
  ignoreCharSet: ";&|",
  boundaries: {
    "[": "]",
    "{": "}",
    '"': '"',
    "'": "'",
  },
}
Where ,
  mileStones    ==> Mile stones tell to start finding boundaries.
  ignoreCharSet ==> Ignore Char inspire to find new mileStone again to start the finding operation.
  boundaries    ==> Boundaries tell to find boundaries between these characters.
  
NB: We can chagange this setup by passing an object during instant creation.

Change the default setup

Suppose our new milestons= "=<>!" our string is: (string= !"(a='4' && b=6)") && (tag : [["abc\'d","(xyz)"],{'abc':true},1,2]) here we just replace "tag =" to "tag :" Now let see the result

import { JsonBoundary } from "json-boundary";
const JB = new JsonBoundary({
  mileStones: "=<>!", // you can change other options also
});

const str = `(string= !"(a='4' && b=6)") && (tag : [["abc\'d","(xyz)"],{'abc':true},1,2])`;
const boundaries = JB.getBoundaries(str);

console.log(boundaries); 


//  [ { start: 10, end: 25 } ] 
//  maShaAllah it capture only string boundary

Features

• getBoundaries ⇒ ok // @param originalString, callback(startIndex, currentIndex, flag) ⇒ this call ones for every charerter's index of the string if provided ; @return all boundary indexes Here, startIndex = last boundary start point, end= current char index of the original string. flag | -1= outside the boundary | 1 = boundary area is running | 0 = boundary area is end. Here, startIndex = last boundary start point, end= current char index of the original string. flag | -1= outside the boundary | 1 = boundary area is running | 0 = boundary area is end.
• getSimple ⇒ ok // @param originalString, identifier ; @return a simplify version of original string and a tracking id to perform operation/s
• replaceOriginal ⇒ ok // @param modifiedString, trackingId; @return replace the original boundary content to our modified string then return it.
• getBoundaryMap ⇒ may be in Progress if needed // @param originalString; @return all boundaries with nasted operation
• others may be included if needed InshaAllah.

Contributing

Contributions are warmly welcomed! Feel free to submit a Pull Request or open an Issue with any suggestions or improvements.