iralib4 v1.0.0

Ira Framework

Hi, it is my first open source library. If you have comments or objections, please report issues or left recommendations. Yes, this framework is similar to Spring Data, I am a Java Developer :)

The goal of framework is to provide a convenient framework to fetch data from a database. To make it possible framework obligates:

• Keep persistence classes small and readable
• Get rid of code duplication
• Use decorators as a imperative logic description

API

First at all, you need to create a repository class and declare it as @Persistant(). The class will be added to persistence context.

To declare a method that executes query have to use the @NativeQuery() decorator. The decorator consumes native SQL query.

@Persistent()
class UserRepository<T> {

    @NativeQuery("SELECT * FROM table LIMIT 20")
    getInfoFromTable(): Promise<T> {
        return new Promise(() => {})
    }

}

Another way to use a native query is to use @NamedQuery(). To make it possible, you should create .yaml file with the mapping name => query:

GET_INFO_FROM_TABLE:
  SELECT * FROM public.t_faq LIMIT 20

@Persistent('./queries/sqls.yaml')
class UserRepository<T> {

    @NamedQuery("GET_INFO_FROM_TABLE")
    getInfoFromTable(): Promise<T> {
        return new Promise(() => {})
    }

}

Parameters

There are two ways how you can pass parameters to both @NamedQuery() and @NativeQuery():

• Use ? as parameter
• Use object with named parameters

Question params:

Question marks are use as placeholders for arguments. The ? are replaced on function's arguments order. If you pass a redundant argument to the function it will be ignored. If you miss one, it will be thrown an exception. Type check lies to developer's responsibility.

@NativeQuery("SELECT * FROM public.t_faq WHERE id = ? AND lang = ?")
findByIdAndLang(id: number, lang: string): Promise<T>  {
    return new Promise(() => {})
}

Named params:

If you pass only argument of NamedArguments instance, framework recognizes it as named params. The named params look for naming match. It replaces all named params to arguments. If you add a redundant param to object argument it will be ignored. If you miss one, it will be thrown an exception. Type check lies to developer's responsibility.

@NativeQuery("SELECT * FROM public.t_faq WHERE id = ?id AND lang = ?lang AND lang LIKE ?lang")
findByIdAndLang(params: NamedArguments): Promise<T>  {
    return new Promise(() => {})
}

Running queries

1. Create a persistent class

   @Persistent()
   class UserRepository<T> {
   
       @NativeQuery("SELECT * FROM table LIMIT 20")
       getInfoFromTable(): Promise<T> {
           return new Promise(() => {})
       }
   
   }

2. Create a database connector. OOTB connectors are MySQL and PostgreSQL. PostgreSQL connector consumes pool configuration of pg package MySQL connector consumes pool configuration of mysql2 package.

   ```javascript
   const postgreConnector = new PostgreSQLConnector(POSTGRESQL_DB_CONNECTION);
   ```

3. Create instance of your repository:

   const userRepository = PersistentExecutor(new UserRepository(), postgreConnector);

4. Look the result :)

   userRepository.findByIdAndLang(new NamedArguments({
       lang: 'en',
       id: 2
   })).then((resp: any) => console.log(resp));

If there is a need to create an own connector, you can use IraPersistentConnector interface to
come up with a connection logic and a transaction handling. 

Typed result set

The framework supports type binding. If we use a typescript, possibly you want to fetch data as a class. It is possible by defining a required model. Notice, such class has to have _variable field notation. Apparently, we consider such variables as private, for this point it is better to make them public and initialized. Otherwise, variables won't be visible. Any methods can be declared to obtain the result. I agree it is not the best way to bind result to structure, but such idea occurred to me as an extra non-main feature.

class UserModel implements Model {
    public _id: number = 0;
    public _lang: string = '';

    getId(): number {
        return this._id;
    }

    getLang(): string {
        return this._lang;
    }
}
const userRepository = PersistentExecutor(new UserRepository<UserModel>(), client, UserModel);
userRepository.findByIdAndLang(new NamedArguments({
    lang: 'en',
    id: 2
})).then((resp: UserModel) => resp instanceof UserModel ); // => true