objective_db 0.2.3+17

JSON based Database

Objective DB

JSON based Database.

Hecho en 🇵🇷 por Radamés J. Valentín Reyes

Status

Experimental/Under Development

Importing

import 'package:objective_db/objective_db.dart';

About the project

• The program will throw errors every time an error is encountered or a forbidden operation is attempted(such as editing the uuid).
• uuid's in this project are composed of 40 alphanumeric characters.
• All data is stored as .json and returned as Map<String,dynamic>
• When insertin Map<String,dynamic> a new file will be created and a reference to it will be stored in the parent .json object.

Functions, classes and methods

Entry

Entry class is the root of the file structure.

Entry entry = Entry(dbPath: "./database");

Select method

returns a DbObject which contains many more useful methods like insert and delete.

Entry entry = Entry(dbPath: "./database");
DbObject dbObject = entry.select();

Insert method

If the value is a double, int or String the insert method will add the key to the selected Map, if the key already exists the value will be replaced. If you you try to insert a Map a new file will be created and a reference to the file will be generated. If the value you try to replace has a Map assigned to it you will get an error. If you try to insert a List<Map<String,dynamic>> new files and references will be generated.

Entry entry = Entry(dbPath: "./database");
entry.select().insert(
  key: "Stores",
  value: [
    {
      "Name": "Frappé inc",
      "balance": 18.59,
    },
    {
      "Name": "Rica Pizza",
      "balance": 19000,
    },
  ],
);

View method

Returns a Map<String,dynamic> with parsed .json contents. You will see that the only property that stored Map<String,dynamic> contains is "uuid". The reason is that this are references not the actual Object.

Entry entry = Entry(dbPath: "./database");
List<DbObject> objects = entry.select().selectMultiple(
  key: "Stores",
);
for(DbObject object in objects){
  print(object.view());
}

Delete method

If your delete target is an object reference(Map<String,dynamic> with uuid) deletes the object and all linked/referenced objects(children).

Entry entry = Entry(dbPath: "./database");
List<DbObject> objects = entry.select().selectMultiple(
  key: "Stores",
);
DbObject pizzaPlace = objects.firstWhere((element)=> (element.view()["Name"] as String).toLowerCase().contains("pizza"));
entry.select().delete(
  key: "Stores", 
  uuid: pizzaPlace.uuid,
);

Delete key method

If your target is a String, double or int, the property gets removed from the target object.

Entry entry = Entry(dbPath: "./database");
entry.select().deleteKey(key: "string");

Pop method

If the key value is of type List it will remove the element at the specified index.

Entry entry = Entry(dbPath: "./database");
entry.select().pop(
  index: 1, 
  key: "numbers",
);

Insert at method

If the key value is a List the specified value will be inserted at the specified index.

Entry entry = Entry(dbPath: "./database");
entry.select().insertAt(
  index: 1, 
  key: "numbers",
  value: [
    78,
  ],
);

Replace at method

Replaces the value at the specified index. Since objects store a reference to a file containing the entire object they cannot be replaced.

Entry entry = Entry(dbPath: "./database");
entry.select().replaceAt(
  index: 1, 
  key: "numbers",
  value: [
    1105,
  ],
);

Move item method

Moves item on the list

Entry entry = Entry(dbPath: "./database");
entry.select().move(
  key: "numbers", 
  from: 3, 
  to: 2,
);

Swap item method

Swaps the position of list items

Entry entry = Entry(dbPath: "./database");
entry.select().swap(
  key: "numbers", 
  from: 0, 
  to: 1,
);

Encryption

You can now Encrypt, Decrypt and change the password of the databases. Note: By assigning encryption keys to the Objects you will automatically encrypt files. Encryption is off by default. The longer the password the more secure but the more time it takes to compute. It is possible to generate extremely lange numbers that the computer cannot compute. RSA encryption is beign used in the background.

Additional import

import 'package:einfache_krypto/einfache_krypto.dart';

Encrypt database

Entry entry = Entry(
 dbPath: "./database",
 cipherKeys: CipherGen(seed: 7863),
);
entry.encryptEntireDatabase();

Decrypt database

Entry entry = Entry(
 dbPath: "./database",
 cipherKeys: CipherGen(seed: 7863),
);
entry.decryptEntireDatabase();

Change database password

CipherGen newPassword = CipherGen(seed: 1034);
Entry entry = Entry(
 dbPath: "./database",
 cipherKeys: newPassword,
);
entry.changeDatabasePassword(
 oldPassword: CipherGen(
   seed: 7863,
 ),
);