How to handle filters in NestJS?

19 Replies

kapa.ai•11mo ago

Hi @yepmad. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave: ---------------------- To handle filters in NestJS with refine, you would typically use the CrudFilters array to filter results based on some field’s values. You can use more than one filter and even the or operator can be used to combine multiple filters. Here is an example of how you can handle filters in a data provider:

import { DataProvider } from "@refinedev/core";  
  
const dataProvider = (): DataProvider => ({  
 getList: async ({ resource, pagination, filters, sorters }) => {  
 if (filters) {  
 filters.map((filter) => {  
 if (filter.operator !== "or" && filter.operator !== "and" && "field" in filter) {  
 // Handle your logical filters here  
 // console.log(typeof filter); // LogicalFilter  
 } else {  
 // Handle your conditional filters here  
 // console.log(typeof filter); // ConditionalFilter  
 }  
 });  
 }  
 },  
});

import { DataProvider } from "@refinedev/core";  
  
const dataProvider = (): DataProvider => ({  
 getList: async ({ resource, pagination, filters, sorters }) => {  
 if (filters) {  
 filters.map((filter) => {  
 if (filter.operator !== "or" && filter.operator !== "and" && "field" in filter) {  
 // Handle your logical filters here  
 // console.log(typeof filter); // LogicalFilter  
 } else {  
 // Handle your conditional filters here  
 // console.log(typeof filter); // ConditionalFilter  
 }  
 });  
 }  
 },  
});

In this example, the filters are checked and mapped. If the filter operator is not "or" or "and" and the filter has a "field", it is a logical filter and is handled accordingly. If not, it is a conditional filter and is handled differently. Refine supports or and and filtering logic for several data providers including NestJS CRUD. You can find more information about handling filters in the refine documentation (https://refine.dev/docs/advanced-tutorials/data-provider/handling-filters/). ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------

kapa.ai•11mo ago

<@331304553641279490> kapa.ai is still learning and improving, please let us know how it did by reacting below

inland-turquoise•11mo ago

@kapa.ai Ok, but how can I combine it with DTO?

kapa.ai•11mo ago

Let me check the knowledge base for you. One moment! :books: ---------------------- Hmm, I don't know enough to give you a confident answer yet. The provided extracts do not contain specific information on how to combine filters with DTOs (Data Transfer Objects) in NestJS using refine. However, you can refer to the refine documentation (https://refine.dev/docs) for more information and examples on how to use refine with different data providers. For more specific information on using DTOs in NestJS, you might want to check the NestJS documentation (https://docs.nestjs.com/). ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------

kapa.ai•11mo ago

<@331304553641279490> kapa.ai is still learning and improving, please let us know how it did by reacting below

kapa.ai•11mo ago

Let me check the knowledge base for you. One moment! :books: Sorry @yepmad, I seem to be having a bit of trouble. Don't worry though, I've pinged my supprt and they will try to fix me up! :technologist: Perhaps try again in 15mins?

inland-turquoise•11mo ago

@kapa.ai How I suposed to handle that url in the back-end? http://localhost:5000/institution?filter%5B0%5D=id%7C%7C%24in%7C%7C734b6eac-ded5-4789-8491-63b788515a22%2Cb3e49fde-6fb3-423a-b882-4f815d6302dd

kapa.ai•11mo ago

Let me check the knowledge base for you. One moment! :books: ---------------------- The URL you provided includes query parameters that represent filters. The filter in your URL is filter[0]=id||$in||734b6eac-ded5-4789-8491-63b788515a22,b3e49fde-6fb3-423a-b882-4f815d6302dd. This filter is looking for records where the id is in the provided list of ids. In your backend, you would need to parse these query parameters and convert them into a format that your database can understand. Here's a basic example of how you might do this in a NestJS application:

import { Controller, Get, Query } from '@nestjs/common';

@Controller('institution')
export class InstitutionController {
  @Get()
  async getInstitutions(@Query('filter') filters: string[]): Promise<any> {
    // Parse the filters
    const parsedFilters = filters.map(filter => {
      const [field, operator, value] = filter.split('||');
      return { field, operator, value: value.split(',') };
    });

    // Use the parsed filters to query your database
    // This will depend on what database and ORM you are using
  }
}

import { Controller, Get, Query } from '@nestjs/common';

@Controller('institution')
export class InstitutionController {
  @Get()
  async getInstitutions(@Query('filter') filters: string[]): Promise<any> {
    // Parse the filters
    const parsedFilters = filters.map(filter => {
      const [field, operator, value] = filter.split('||');
      return { field, operator, value: value.split(',') };
    });

    // Use the parsed filters to query your database
    // This will depend on what database and ORM you are using
  }
}

In this example, the getInstitutions method takes the filter query parameter, which is an array of strings. Each filter is split into its field, operator, and value. The value is further split into an array of ids. Please note that this is a simplified example and might not cover all cases. You would need to adapt this to your specific use case and handle other operators and filter formats as necessary. For more information on handling filters in refine, you can refer to the refine documentation (https://refine.dev/docs/advanced-tutorials/data-provider/handling-filters/). ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------

kapa.ai•11mo ago

<@331304553641279490> kapa.ai is still learning and improving, please let us know how it did by reacting below

inland-turquoise•11mo ago

@kapa.ai Thank you for your last reply! Based on that, if I'm using Prisma. How can I use the parsed filters?

kapa.ai•11mo ago

Let me check the knowledge base for you. One moment! :books: ---------------------- Once you have parsed the filters from the URL, you can use them to build a query with Prisma. Here's a basic example of how you might do this:

import { PrismaClient } from '@prisma/client';
import { Controller, Get, Query } from '@nestjs/common';

const prisma = new PrismaClient();

@Controller('institution')
export class InstitutionController {
  @Get()
  async getInstitutions(@Query('filter') filters: string[]): Promise<any> {
    // Parse the filters
    const parsedFilters = filters.map(filter => {
      const [field, operator, value] = filter.split('||');
      return { field, operator, value: value.split(',') };
    });

    // Build the where object for Prisma
    const where = parsedFilters.reduce((acc, filter) => {
      if (filter.operator === '$in') {
        return { ...acc, [filter.field]: { in: filter.value } };
      }
      // Handle other operators as necessary
      return acc;
    }, {});

    // Use the where object to query your database with Prisma
    const institutions = await prisma.institution.findMany({ where });

    return institutions;
  }
}

import { PrismaClient } from '@prisma/client';
import { Controller, Get, Query } from '@nestjs/common';

const prisma = new PrismaClient();

@Controller('institution')
export class InstitutionController {
  @Get()
  async getInstitutions(@Query('filter') filters: string[]): Promise<any> {
    // Parse the filters
    const parsedFilters = filters.map(filter => {
      const [field, operator, value] = filter.split('||');
      return { field, operator, value: value.split(',') };
    });

    // Build the where object for Prisma
    const where = parsedFilters.reduce((acc, filter) => {
      if (filter.operator === '$in') {
        return { ...acc, [filter.field]: { in: filter.value } };
      }
      // Handle other operators as necessary
      return acc;
    }, {});

    // Use the where object to query your database with Prisma
    const institutions = await prisma.institution.findMany({ where });

    return institutions;
  }
}

In this example, the getInstitutions method takes the filter query parameter, which is an array of strings. Each filter is split into its field, operator, and value. The value is further split into an array of ids. The parsed filters are then used to build a where object that Prisma can use to query the database. In this case, if the operator is $in, the filter is converted into a format that Prisma understands ({ in: filter.value }). Please note that this is a simplified example and might not cover all cases. You would need to adapt this to your specific use case and handle other operators and filter formats as necessary. For more information on querying with Prisma, you can refer to the Prisma documentation (https://www.prisma.io/docs/concepts/components/prisma-client/filtering-and-sorting). ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------

kapa.ai•11mo ago

<@331304553641279490> kapa.ai is still learning and improving, please let us know how it did by reacting below

inland-turquoise•11mo ago

@kapa.ai @Query('filter') don't work. I got "undefined". What I am missing?

kapa.ai•11mo ago

Let me check the knowledge base for you. One moment! :books: ---------------------- If you're getting undefined for @Query('filter'), it could be because the filter query parameter is not being sent in the request, or it's not being recognized correctly by NestJS. Here are a few things you can check: 1. Check the request: Make sure the request you're sending includes the filter query parameter. You can check this in your browser's network tab or in the tool you're using to send the request (like Postman or curl). 2. Check the parameter name: The @Query() decorator in NestJS is case-sensitive. Make sure the case of 'filter' in @Query('filter') matches the case in the request. 3. Check for array parameters: If filter is an array, you might need to adjust how you're sending or receiving it. In some cases, you might need to use @Query('filter[]') or adjust the syntax in your request. 4. Log the query parameters: You can log all query parameters to see what NestJS is receiving. Try changing your method to something like this:

@Get()
async getInstitutions(@Query() query: any): Promise<any> {
  console.log(query);
  // rest of your code...
}

@Get()
async getInstitutions(@Query() query: any): Promise<any> {
  console.log(query);
  // rest of your code...
}

This will log all query parameters, which can help you see what's being received and if filter is included. If you're still having trouble, you might find it helpful to refer to the NestJS documentation on request handling (https://docs.nestjs.com/controllers#request-object). ---------------------- Note: you can ask me a follow up question by @ mentioning me again :speech_balloon: ----------------------

kapa.ai•11mo ago

<@331304553641279490> kapa.ai is still learning and improving, please let us know how it did by reacting below

inland-turquoise•11mo ago

@kapa.ai I'm receiving 'filter[0]' instead of 'filter' or 'filter[]'

kapa.ai•11mo ago

Let me check the knowledge base for you. One moment! :books: @yepmad That's a great question, but unfortunately I am only capable of responding to a maximum of five questions per thread. Don't hesitate to create a new thread for any further questions you have though. I'm here to help!

inland-turquoise•11mo ago

so sad

stormy-gold•11mo ago

@yepmad please only ask questions related to refine framework. We don't provide support for NestJs. You can check their documentation.