78 lines
2.1 KiB
TypeScript
78 lines
2.1 KiB
TypeScript
import { Type } from '@nestjs/common';
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import { ArgsType, Field, ObjectType } from '@nestjs/graphql';
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import { IsNumber, IsOptional, IsString } from 'class-validator';
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import { PageInfo } from './page-info';
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import { IConnectionArguments } from './interfaces/connection-arguments.interface';
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import { IConnection } from './interfaces/connection.interface';
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import { IEdge } from './interfaces/edge.interface';
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import { IPageInfo } from './interfaces/page-info.interface';
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export type ConnectionCursor = string;
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/**
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* ConnectionArguments
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*/
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@ArgsType()
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export class ConnectionArgs implements IConnectionArguments {
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@Field({ nullable: true, description: 'Paginate before opaque cursor' })
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@IsString()
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@IsOptional()
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public before?: ConnectionCursor;
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@Field({ nullable: true, description: 'Paginate after opaque cursor' })
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@IsString()
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@IsOptional()
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public after?: ConnectionCursor;
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@Field({ nullable: true, description: 'Paginate first' })
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@IsNumber()
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@IsOptional()
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public first?: number;
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@Field({ nullable: true, description: 'Paginate last' })
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@IsNumber()
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@IsOptional()
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public last?: number;
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}
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/**
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* Paginated graphQL class inheritance
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*/
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export function Paginated<T>(classRef: Type<T>): Type<IConnection<T>> {
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@ObjectType(`${classRef.name}Edge`, { isAbstract: true })
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class Edge implements IEdge<T> {
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public name = `${classRef.name}Edge`;
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@Field({ nullable: true })
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public cursor!: ConnectionCursor;
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@Field(() => classRef, { nullable: true })
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public node!: T;
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}
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@ObjectType(`${classRef.name}Connection`, { isAbstract: true })
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class Connection implements IConnection<T> {
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public name = `${classRef.name}Connection`;
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@Field(() => [Edge], { nullable: true })
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public edges!: IEdge<T>[];
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@Field(() => PageInfo, { nullable: true })
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public pageInfo!: IPageInfo;
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@Field()
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totalCount: number;
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}
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return Connection as Type<IConnection<T>>;
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}
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// export const encodeCursor = <Cursor>(cursor: Cursor) =>
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// Buffer.from(JSON.stringify(cursor)).toString('base64');
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// export const decodeCursor = <Cursor>(cursor: string) =>
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// JSON.parse(Buffer.from(cursor, 'base64').toString('ascii')) as Cursor;
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