nestjs-dynamic-filter

A flexible filtering system for NestJS applications. This package provides an easy way to implement complex filtering in your NestJS applications with MongoDB and PostgreSQL support.

Installation

npm install nestjs-dynamic-filter

Features

• Easy-to-use decorators for defining filterable fields
• Support for multiple filter operations (exact, contains, greater than, less than, etc.)
• Automatic Swagger documentation
• Built-in pagination support
• MongoDB/Mongoose integration
• PostgreSQL/TypeORM integration
• Type-safe filtering
• Database-agnostic query building

Quick Start

1. Import the NestjsDynamicFilterModule in your app.module.ts:

For MongoDB:

import { NestjsDynamicFilterModule } from 'nestjs-dynamic-filter';

@Module({
  imports: [
    NestjsDynamicFilterModule.forRoot({
      databaseType: 'mongodb', // Optional, defaults to 'mongodb'
    }),
    // ... other imports
  ],
})
export class AppModule {}

For PostgreSQL:

import { NestjsDynamicFilterModule } from 'nestjs-dynamic-filter';

@Module({
  imports: [
    NestjsDynamicFilterModule.forRoot({
      databaseType: 'postgres',
    }),
    // ... other imports
  ],
})
export class AppModule {}

2. Define your filter DTO:

import { FilterableField, FilterOperationType } from 'nestjs-dynamic-filter';
import { PaginationQueryDto } from 'nestjs-dynamic-filter';

export enum UserStatus {
  ACTIVE = 'ACTIVE',
  INACTIVE = 'INACTIVE'
}

export class UserFilterDto extends PaginationQueryDto {
  @FilterableField()
  name?: string;

  @FilterableField({
    operations: [FilterOperationType.EXACT],
    enum: UserStatus
  })
  status?: UserStatus;

  @FilterableField({
    operations: [FilterOperationType.GTE, FilterOperationType.LTE]
  })
  age?: number;
}

3. Use in your controller:

For MongoDB:

import { FilterBuilderService } from 'nestjs-dynamic-filter';
import { InjectModel } from '@nestjs/mongoose';
import { Model } from 'mongoose';

@Controller('users')
export class UserController {
  constructor(
    private readonly filterBuilder: FilterBuilderService,
    @InjectModel('User') private readonly userModel: Model<User>,
  ) {}

  @Get()
  async findAll(@Query() query: UserFilterDto) {
    const filter = this.filterBuilder.buildQuery(query);
    return this.userModel.find(filter).exec();
  }
}

For PostgreSQL:

import { FilterBuilderService } from 'nestjs-dynamic-filter';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';

@Controller('users')
export class UserController {
  constructor(
    private readonly filterBuilder: FilterBuilderService,
    @InjectRepository(User) private readonly userRepository: Repository<User>,
  ) {}

  @Get()
  async findAll(@Query() query: UserFilterDto) {
    const where = this.filterBuilder.buildQuery(query);
    return this.userRepository.find({ where });
  }
}

Filter Operations

• exact: Exact match
• icontains: Case-insensitive contains
• in: Value in array
• gte: Greater than or equal
• lte: Less than or equal

Query Parameters

For a field named age, you can use:

• age__exact=25
• age__gte=18
• age__lte=65

For text fields:

• name__icontains=john

Advanced Usage

Getting Available Filters

For MongoDB:

import { FilterService } from 'nestjs-dynamic-filter';
import { InjectModel } from '@nestjs/mongoose';
import { Model } from 'mongoose';

@Controller('users')
export class UserController {
  constructor(
    private readonly filterService: FilterService,
    @InjectModel('User') private readonly userModel: Model<User>,
  ) {}

  @Get('@filters')
  async getFilters() {
    return this.filterService.getFilters(UserFilterDto, this.userModel);
  }
}

For PostgreSQL:

import { FilterService } from 'nestjs-dynamic-filter';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';

@Controller('users')
export class UserController {
  constructor(
    private readonly filterService: FilterService,
    @InjectRepository(User) private readonly userRepository: Repository<User>,
  ) {}

  @Get('@filters')
  async getFilters() {
    return this.filterService.getFilters(UserFilterDto, this.userRepository);
  }
}

Custom Filter Operations

@FilterableField({
  operations: [
    FilterOperationType.EXACT,
    FilterOperationType.ICONTAINS,
    FilterOperationType.IN
  ]
})
field?: string;

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT