gotosocial/internal/paging/response.go

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// 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 (
"net/url"
"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 url.Values // 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 {
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{}{},
}
}