Save and Load Diff to Record

This example shows how to save and load Diffs to and from Record. This feature facilitates the saving and sharing of changes between EntityDefs, EntityRelationshipDefs, FieldDefs, IndexDefs, IndexFieldDefs, SchemaDefs and Records.

Java Code Listing

package com.northconcepts.datapipeline.foundations.examples.difference;


import java.math.BigDecimal;
import java.time.LocalDate;

import com.northconcepts.datapipeline.core.Record;
import com.northconcepts.datapipeline.foundations.difference.RecordDiff;

public class SaveDiffToAndFromRecord {

    public static void main(String[] args) {
        Record oldRecord = new Record()
            .setField("name", "John Doe")
            .setField("dob", LocalDate.parse("2000-01-01"))
            .setField("languages", new String[] {"English", "French"})
            .setField("height", 1.70)
            .setField("netIncome", new BigDecimal(100_286.99));

        Record newRecord = new Record()
            .setField("name", "John Doe")
            .setField("age", 24)
            .setField("languages", new String[] {"English", "French", "Spanish"})
            .setField("height", 1.73)
            .setField("netIncome", new BigDecimal(120_286.99));

        RecordDiff oldDiff = RecordDiff.diff("userRecord", oldRecord, newRecord, "height", "netIncome");
        System.out.println("old diff: " + oldDiff);

        System.out.println("===============================================================");

        Record diffRecord = oldDiff.toRecord();
        System.out.println(diffRecord);

        System.out.println("===============================================================");

        RecordDiff newDiff = new RecordDiff().fromRecord(diffRecord);
        System.out.println("new diff: " + newDiff);
    }
}

Code Walkthrough

1. An oldRecord is created and initialized with the following fields: name, dob, languages, height, and netIncome.
2. A newRecord is created and initialized with the following fields: name, age, languages, height, and netIncome.
3. RecordDiff instance is created by calling diff() method with the following arguments: name of the diff, the old record, the new record, and a list of field names to exclude from the comparison.
4. We save the Diff as a Record on line 37 and then use this Record after instantiating a new Diff  using the fromRecord() method on line 42.

Console Output

old diff: {
  "children" : [ {
    "name" : "name",
    "type" : "NONE"
  }, {
    "name" : "dob",
    "type" : "REMOVED"
  }, {
    "name" : "English",
    "type" : "NONE"
  }, {
    "name" : "French",
    "type" : "NONE"
  }, {
    "name" : "Spanish",
    "type" : "ADDED"
  }, {
    "name" : "age",
    "type" : "ADDED"
  } ],
  "name" : "userRecord",
  "type" : "CHANGED"
}
===============================================================
Record (MODIFIED) (has child records) {
    0:[__class__]:STRING=[com.northconcepts.datapipeline.foundations.difference.RecordDiff]:String
    1:[name]:STRING=[userRecord]:String
    2:[type]:UNDEFINED=[CHANGED]:DiffType
    3:[oldValue]:RECORD=[
        Record (MODIFIED) (is child record) {
            0:[name]:STRING=[John Doe]:String
            1:[dob]:UNDEFINED=[2000-01-01]:com.amazonaws.thirdparty.joda.time.LocalDate
            2:[languages]:ARRAY of STRING=[[English, French]]:ArrayValue
            3:[height]:DOUBLE=[1.7]:Double
            4:[netIncome]:BIG_DECIMAL=[100286.990000000005238689482212066650390625]:BigDecimal
        }]:Record
    4:[newValue]:RECORD=[
        Record (MODIFIED) (is child record) {
            0:[name]:STRING=[John Doe]:String
            1:[age]:INT=[24]:Integer
            2:[languages]:ARRAY of STRING=[[English, French, Spanish]]:ArrayValue
            3:[height]:DOUBLE=[1.73]:Double
            4:[netIncome]:BIG_DECIMAL=[120286.990000000005238689482212066650390625]:BigDecimal
        }]:Record
    5:[children]:ARRAY of RECORD=[[
        Record (MODIFIED) (is child record) {
            0:[__class__]:STRING=[com.northconcepts.datapipeline.foundations.difference.PropertyDiff]:String
            1:[name]:STRING=[name]:String
            2:[type]:UNDEFINED=[NONE]:DiffType
            3:[oldValue]:STRING=[John Doe]:String
            4:[newValue]:STRING=[John Doe]:String
            5:[children]:ARRAY of UNDEFINED=[[]]:ArrayValue
        }, 
        Record (MODIFIED) (is child record) {
            0:[__class__]:STRING=[com.northconcepts.datapipeline.foundations.difference.PropertyDiff]:String
            1:[name]:STRING=[dob]:String
            2:[type]:UNDEFINED=[REMOVED]:DiffType
            3:[oldValue]:UNDEFINED=[null]
            4:[newValue]:UNDEFINED=[null]
            5:[children]:ARRAY of UNDEFINED=[[]]:ArrayValue
        }, 
        Record (MODIFIED) (is child record) {
            0:[__class__]:STRING=[com.northconcepts.datapipeline.foundations.difference.PropertyDiff]:String
            1:[name]:STRING=[English]:String
            2:[type]:UNDEFINED=[NONE]:DiffType
            3:[oldValue]:STRING=[English]:String
            4:[newValue]:STRING=[English]:String
            5:[children]:ARRAY of UNDEFINED=[[]]:ArrayValue
        }, 
        Record (MODIFIED) (is child record) {
            0:[__class__]:STRING=[com.northconcepts.datapipeline.foundations.difference.PropertyDiff]:String
            1:[name]:STRING=[French]:String
            2:[type]:UNDEFINED=[NONE]:DiffType
            3:[oldValue]:STRING=[French]:String
            4:[newValue]:STRING=[French]:String
            5:[children]:ARRAY of UNDEFINED=[[]]:ArrayValue
        }, 
        Record (MODIFIED) (is child record) {
            0:[__class__]:STRING=[com.northconcepts.datapipeline.foundations.difference.PropertyDiff]:String
            1:[name]:STRING=[Spanish]:String
            2:[type]:UNDEFINED=[ADDED]:DiffType
            3:[oldValue]:UNDEFINED=[null]
            4:[newValue]:STRING=[Spanish]:String
            5:[children]:ARRAY of UNDEFINED=[[]]:ArrayValue
        }, 
        Record (MODIFIED) (is child record) {
            0:[__class__]:STRING=[com.northconcepts.datapipeline.foundations.difference.PropertyDiff]:String
            1:[name]:STRING=[age]:String
            2:[type]:UNDEFINED=[ADDED]:DiffType
            3:[oldValue]:UNDEFINED=[null]
            4:[newValue]:INT=[24]:Integer
            5:[children]:ARRAY of UNDEFINED=[[]]:ArrayValue
        }]]:ArrayValue
}

===============================================================
new diff: {
  "children" : [ {
    "name" : "name",
    "type" : "NONE"
  }, {
    "name" : "dob",
    "type" : "REMOVED"
  }, {
    "name" : "English",
    "type" : "NONE"
  }, {
    "name" : "French",
    "type" : "NONE"
  }, {
    "name" : "Spanish",
    "type" : "ADDED"
  }, {
    "name" : "age",
    "type" : "ADDED"
  } ],
  "name" : "userRecord",
  "type" : "CHANGED"
}