| // Copyright 2019 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package middleware |
| |
| import ( |
| "bytes" |
| "context" |
| "net/http" |
| "regexp" |
| "strings" |
| |
| "golang.org/x/mod/module" |
| "golang.org/x/pkgsite/internal" |
| "golang.org/x/pkgsite/internal/log" |
| ) |
| |
| const ( |
| latestMinorClassPlaceholder = "$$GODISCOVERY_LATESTMINORCLASS$$" |
| LatestMinorVersionPlaceholder = "$$GODISCOVERY_LATESTMINORVERSION$$" |
| latestMajorClassPlaceholder = "$$GODISCOVERY_LATESTMAJORCLASS$$" |
| LatestMajorVersionPlaceholder = "$$GODISCOVERY_LATESTMAJORVERSION$$" |
| LatestMajorVersionURL = "$$GODISCOVERY_LATESTMAJORVERSIONURL$$" |
| ) |
| |
| // latestInfoRegexp extracts values needed to determine the latest-version badge from a page's HTML. |
| var latestInfoRegexp = regexp.MustCompile(`data-version="([^"]*)" data-mpath="([^"]*)" data-ppath="([^"]*)" data-pagetype="([^"]*)"`) |
| |
| type latestMinorFunc func(ctx context.Context, packagePath, modulePath, pageType string) string |
| type latestMajorFunc func(ctx context.Context, seriesPath string) string |
| |
| // LatestVersions replaces the HTML placeholder values for the badge and banner |
| // that displays whether the version of the package or module being served is |
| // the latest minor version (badge) and the latest major version (banner). |
| func LatestVersions(latestMinor latestMinorFunc, latestMajor latestMajorFunc) Middleware { |
| return func(h http.Handler) http.Handler { |
| return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| crw := &capturingResponseWriter{ResponseWriter: w} |
| h.ServeHTTP(crw, r) |
| body := crw.bytes() |
| matches := latestInfoRegexp.FindSubmatch(body) |
| if matches != nil { |
| version := string(matches[1]) |
| // The template package converts '+' to its HTML entity. |
| version = strings.Replace(version, "+", "+", -1) |
| modulePath := string(matches[2]) |
| seriesPath := internal.SeriesPathForModule(modulePath) |
| _, majorVersion, _ := module.SplitPathVersion(modulePath) |
| packagePath := string(matches[3]) |
| pageType := string(matches[4]) |
| latestMinorVersion := latestMinor(r.Context(), packagePath, modulePath, pageType) |
| latestMinorClass := "DetailsHeader-badge" |
| switch { |
| case latestMinorVersion == "": |
| latestMinorClass += "--unknown" |
| case latestMinorVersion == version: |
| latestMinorClass += "--latest" |
| default: |
| latestMinorClass += "--goToLatest" |
| } |
| latestMajorVersion := latestMajor(r.Context(), seriesPath) |
| latestMajorVersionText := latestMajorVersion |
| if len(latestMajorVersionText) > 0 { |
| latestMajorVersionText = latestMajorVersionText[1:] |
| } |
| latestMajorClass := "" |
| // If the latest major version is the same as the major version of the current |
| // module path, it is currently the latest version so we don't show the banner. |
| // If an error occurs finding a major version (i.e: not found) an empty string |
| // is returned in which case we also don't show the banner. |
| if majorVersion == latestMajorVersion || latestMajorVersion == "" { |
| latestMajorClass += " DetailsHeader-banner--latest" |
| } |
| body = bytes.ReplaceAll(body, []byte(latestMinorClassPlaceholder), []byte(latestMinorClass)) |
| body = bytes.ReplaceAll(body, []byte(LatestMinorVersionPlaceholder), []byte(latestMinorVersion)) |
| body = bytes.ReplaceAll(body, []byte(latestMajorClassPlaceholder), []byte(latestMajorClass)) |
| body = bytes.ReplaceAll(body, []byte(LatestMajorVersionPlaceholder), []byte(latestMajorVersionText)) |
| body = bytes.ReplaceAll(body, []byte(LatestMajorVersionURL), []byte(seriesPath+latestMajorVersion)) |
| } |
| if _, err := w.Write(body); err != nil { |
| log.Errorf(r.Context(), "LatestVersions, writing: %v", err) |
| } |
| }) |
| } |
| } |