kpidoff / prisma-extension-pagination

Prisma Client extension for pagination

Prisma Pagination Extension

Introduction

Prisma Client extension for pagination.

Note Breaking change in 0.5.0

Features

• Page number pagination
• Cursor-based pagination
• Fully tested

Installation

npm i prisma-extension-pagination

Install extension to all models

import { PrismaClient } from "@prisma/client";
import pagination from "prisma-extension-pagination";

const prisma = new PrismaClient().$extends(pagination());

Install extension on some models

import { PrismaClient } from "@prisma/client";
import { paginate } from "prisma-extension-pagination";

const prisma = new PrismaClient().$extends({
  model: {
    user: {
      paginate,
    },
  },
});

Change default settings

import { PrismaClient } from "@prisma/client";
import pagination from "prisma-extension-pagination";

const prisma = new PrismaClient().$extends(
  pagination({
    pages: {
      limit: 10, // set default limit to 10
      includePageCount: true, // include counters by default
    },
    cursor: {
      limit: 10, // set default limit to 10

      // set default cursor serialization/deserialization
      getCursor(user: UserType) {
        // ...
      },
      parseCursor(cursor) {
        // ...
      },
    },
  })
);

When using the extension on some models, you need to use createPaginator function to set the default values:

import { PrismaClient } from "@prisma/client";
import { createPaginator } from "prisma-extension-pagination";

const paginate = createPaginator({
  // available settings are the same as above
  pages: {
    // ...
  },
  cursor: {
    //...
  },
});

// You can create many paginators with different settings.
// They can be reused for different models.

const prisma = new PrismaClient().$extends({
  model: {
    user: {
      paginate,
    },
    post: {
      paginate,
    },
  },
});

Usage

Page number pagination

Page number pagination uses limit to select a limited range and page to load a specific page of results.

• Load first page
• Load specific page
• Calculate page count

Load first page

const [users, meta] = prisma.user
  .paginate({
    select: {
      id: true,
    }
  })
  .withPages({
    limit: 10,
  });

// meta contains the following
{
  currentPage: 1,
  isFirstPage: true,
  isLastPage: false,
  previousPage: null,
  nextPage: 2,
}

Load specific page

const [users, meta] = prisma.user
  .paginate()
  .withPages({
    limit: 10,
    page: 2,
  });

// meta contains the following
{
  currentPage: 2,
  isFirstPage: false,
  isLastPage: false,
  previousPage: 1,
  nextPage: 3,
}

Calculate page count

const [users, meta] = prisma.user
  .paginate()
  .withPages({
    limit: 10,
    page: 2,
    includePageCount: true,
  });

// meta contains the following
{
  currentPage: 2,
  isFirstPage: false,
  isLastPage: false,
  previousPage: 1,
  nextPage: 3,
  pageCount: 10, // the number of pages is calculated
  totalCount: 100, // the total number of results is calculated
}

Cursor-based pagination

Cursor-based pagination uses limit to select a limited range and before or after to return a set of results before or after a given cursor.

• Load first records
• Load next page
• Load previous page
• Custom cursor serialization

Load first records

const [users, meta] = prisma.user
  .paginate({
    select: {
      id: true,
    }
  })
  .withCursor({
    limit: 10,
  });

// meta contains the following
{
  hasPreviousPage: false,
  hasNextPage: true,
  startCursor: "1",
  endCursor: "10"
}

Load next page

const [users, meta] = prisma.user
  .paginate()
  .withCursor({
    limit: 10,
    after: "10"
  });

// meta contains the following
{
  hasPreviousPage: true,
  hasNextPage: true,
  startCursor: "11",
  endCursor: "20"
}

Load previous page

const [users, meta] = prisma.user
  .paginate()
  .withCursor({
    limit: 10,
    before: "11"
  });

// meta contains the following
{
  hasPreviousPage: false,
  hasNextPage: true,
  startCursor: "1",
  endCursor: "10"
}

Custom cursor serialization

const getCustomCursor = (postId: number, userId: number) =>
  [postId, userId].join(":");

const parseCustomCursor = (cursor: string) =>
  cursor.split(":");

const [results, meta] = await prisma.postOnUser
  .paginate({
    select: {
      postId: true,
      userId: true,
    },
  })
  .withCursor({
    limit: 10,
    after: getCustomCursor(1, 1), // "1:1"

    // custom cursor serialization
    getCursor({ postId, userId }) {
      return getCustomCursor(postId, userId)
    },

    // custom cursor deserialization
    parseCursor(cursor) {
      const [postId, userId] = parseCustomCursor(cursor);

      return {
        userId_postId: {
          postId: parseInt(postId),
          userId: parseInt(userId),
        },
      };
    },
  });

// meta contains the following
{
  hasPreviousPage: false,
  hasNextPage: true,
  startCursor: "1:2",
  endCursor: "1:11"
}

License

This project is licensed under the terms of the MIT license.