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Diffstat (limited to 'internal/paging/response.go')
-rw-r--r-- | internal/paging/response.go | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/internal/paging/response.go b/internal/paging/response.go new file mode 100644 index 000000000..498b42d34 --- /dev/null +++ b/internal/paging/response.go @@ -0,0 +1,91 @@ +// GoToSocial +// Copyright (C) GoToSocial Authors admin@gotosocial.org +// SPDX-License-Identifier: AGPL-3.0-or-later +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Affero General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Affero General Public License for more details. +// +// You should have received a copy of the GNU Affero General Public License +// along with this program. If not, see <http://www.gnu.org/licenses/>. + +package paging + +import ( + "strings" + + apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model" + "github.com/superseriousbusiness/gotosocial/internal/config" +) + +// ResponseParams models the parameters to pass to PageableResponse. +// +// The given items will be provided in the paged response. +// +// The other values are all used to create the Link header so that callers know +// which endpoint to query next and previously in order to do paging. +type ResponseParams struct { + Items []interface{} // Sorted slice of items (statuses, notifications, etc) + Path string // path to use for next/prev queries in the link header + Next *Page // page details for the next page + Prev *Page // page details for the previous page + Query []string // any extra query parameters to provide in the link header, should be in the format 'example=value' +} + +// PackageResponse is a convenience function for returning +// a bunch of pageable items (notifications, statuses, etc), as well +// as a Link header to inform callers of where to find next/prev items. +func PackageResponse(params ResponseParams) *apimodel.PageableResponse { + if len(params.Items) == 0 { + // No items to page through. + return EmptyResponse() + } + + var ( + // Extract paging params. + nextPg = params.Next + prevPg = params.Prev + + // Host app configuration. + proto = config.GetProtocol() + host = config.GetHost() + + // Combined next/prev page link header parts. + linkHeaderParts = make([]string, 0, 2) + ) + + // Build the next / previous page links from page and host config. + nextLink := nextPg.ToLink(proto, host, params.Path, params.Query) + prevLink := prevPg.ToLink(proto, host, params.Path, params.Query) + + if nextLink != "" { + // Append page "next" link to header parts. + linkHeaderParts = append(linkHeaderParts, `<`+nextLink+`>; rel="next"`) + } + + if prevLink != "" { + // Append page "prev" link to header parts. + linkHeaderParts = append(linkHeaderParts, `<`+prevLink+`>; rel="prev"`) + } + + return &apimodel.PageableResponse{ + Items: params.Items, + NextLink: nextLink, + PrevLink: prevLink, + LinkHeader: strings.Join(linkHeaderParts, ", "), + } +} + +// EmptyResponse just returns an empty +// PageableResponse with no link header or items. +func EmptyResponse() *apimodel.PageableResponse { + return &apimodel.PageableResponse{ + Items: []interface{}{}, + } +} |