58 lines
1.6 KiB
TypeScript
58 lines
1.6 KiB
TypeScript
import querystring from "querystring";
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import { Next } from "koa";
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import { Pagination } from "@shared/constants";
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import { InvalidRequestError } from "@server/errors";
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import { AppContext } from "@server/types";
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export default function pagination() {
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return async function paginationMiddleware(ctx: AppContext, next: Next) {
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const opts = {
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defaultLimit: Pagination.defaultLimit,
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defaultOffset: Pagination.defaultOffset,
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maxLimit: Pagination.maxLimit,
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};
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const query = ctx.request.query;
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const body = ctx.request.body;
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let limit = query.limit || body.limit;
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let offset = query.offset || body.offset;
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if (limit && isNaN(limit)) {
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throw InvalidRequestError(`Pagination limit must be a valid number`);
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}
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if (offset && isNaN(offset)) {
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throw InvalidRequestError(`Pagination offset must be a valid number`);
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}
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limit = parseInt(limit || opts.defaultLimit, 10);
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offset = parseInt(offset || opts.defaultOffset, 10);
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if (limit > opts.maxLimit) {
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throw InvalidRequestError(
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`Pagination limit is too large (max ${opts.maxLimit})`
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);
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}
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if (limit <= 0) {
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throw InvalidRequestError(`Pagination limit must be greater than 0`);
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}
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if (offset < 0) {
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throw InvalidRequestError(
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`Pagination offset must be greater than or equal to 0`
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);
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}
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query.limit = String(limit);
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query.offset = String(limit + offset);
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ctx.state.pagination = {
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limit,
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offset,
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nextPath: `/api${ctx.request.path}?${querystring.stringify(query)}`,
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};
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return next();
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};
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}
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