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Diffstat (limited to 'src/http/posts.go')
-rw-r--r--src/http/posts.go421
1 files changed, 421 insertions, 0 deletions
diff --git a/src/http/posts.go b/src/http/posts.go
new file mode 100644
index 0000000..c3f6363
--- /dev/null
+++ b/src/http/posts.go
@@ -0,0 +1,421 @@
+package http
+
+import (
+ "bytes"
+ "context"
+ "errors"
+ "fmt"
+ "html/template"
+ "net/http"
+ "path/filepath"
+ "strings"
+ txttpl "text/template"
+ "time"
+
+ "github.com/gomarkdown/markdown"
+ "github.com/gomarkdown/markdown/html"
+ "github.com/gomarkdown/markdown/parser"
+ "github.com/mediocregopher/blog.mediocregopher.com/srv/http/apiutil"
+ "github.com/mediocregopher/blog.mediocregopher.com/srv/post"
+ "github.com/mediocregopher/mediocre-go-lib/v2/mctx"
+)
+
+func (a *api) parsePostBody(post post.Post) (*txttpl.Template, error) {
+ tpl := txttpl.New("root")
+ tpl = tpl.Funcs(txttpl.FuncMap(a.tplFuncs()))
+
+ tpl = txttpl.Must(tpl.New("image.html").Parse(mustReadTplFile("image.html")))
+ tpl = tpl.Funcs(txttpl.FuncMap{
+ "Image": func(id string) (string, error) {
+
+ tplPayload := struct {
+ ID string
+ Resizable bool
+ }{
+ ID: id,
+ Resizable: isImgResizable(id),
+ }
+
+ buf := new(bytes.Buffer)
+ if err := tpl.ExecuteTemplate(buf, "image.html", tplPayload); err != nil {
+ return "", err
+ }
+
+ return buf.String(), nil
+ },
+ })
+
+ tpl, err := tpl.New(post.ID + "-body.html").Parse(post.Body)
+
+ if err != nil {
+ return nil, err
+ }
+
+ return tpl, nil
+}
+
+type postTplPayload struct {
+ post.StoredPost
+ SeriesPrevious, SeriesNext *post.StoredPost
+ Body template.HTML
+}
+
+func (a *api) postToPostTplPayload(storedPost post.StoredPost) (postTplPayload, error) {
+
+ bodyTpl, err := a.parsePostBody(storedPost.Post)
+ if err != nil {
+ return postTplPayload{}, fmt.Errorf("parsing post body as template: %w", err)
+ }
+
+ bodyBuf := new(bytes.Buffer)
+
+ if err := bodyTpl.Execute(bodyBuf, nil); err != nil {
+ return postTplPayload{}, fmt.Errorf("executing post body as template: %w", err)
+ }
+
+ // this helps the markdown renderer properly parse pages which end in a
+ // `</script>` tag... I don't know why.
+ _, _ = bodyBuf.WriteString("\n")
+
+ parserExt := parser.CommonExtensions | parser.AutoHeadingIDs
+ parser := parser.NewWithExtensions(parserExt)
+
+ htmlFlags := html.HrefTargetBlank
+ htmlRenderer := html.NewRenderer(html.RendererOptions{Flags: htmlFlags})
+
+ renderedBody := markdown.ToHTML(bodyBuf.Bytes(), parser, htmlRenderer)
+
+ tplPayload := postTplPayload{
+ StoredPost: storedPost,
+ Body: template.HTML(renderedBody),
+ }
+
+ if series := storedPost.Series; series != "" {
+
+ seriesPosts, err := a.params.PostStore.GetBySeries(series)
+ if err != nil {
+ return postTplPayload{}, fmt.Errorf(
+ "fetching posts for series %q: %w", series, err,
+ )
+ }
+
+ var foundThis bool
+
+ for i := range seriesPosts {
+
+ seriesPost := seriesPosts[i]
+
+ if seriesPost.ID == storedPost.ID {
+ foundThis = true
+ continue
+ }
+
+ if !foundThis {
+ tplPayload.SeriesNext = &seriesPost
+ continue
+ }
+
+ tplPayload.SeriesPrevious = &seriesPost
+ break
+ }
+ }
+
+ return tplPayload, nil
+}
+
+func (a *api) renderPostHandler() http.Handler {
+
+ tpl := a.mustParseBasedTpl("post.html")
+ renderPostsIndexHandler := a.renderPostsIndexHandler()
+ renderEditPostHandler := a.renderEditPostHandler(false)
+
+ return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+
+ id := strings.TrimSuffix(filepath.Base(r.URL.Path), ".html")
+
+ if id == "/" {
+ renderPostsIndexHandler.ServeHTTP(rw, r)
+ return
+ }
+
+ if _, ok := r.URL.Query()["edit"]; ok {
+ renderEditPostHandler.ServeHTTP(rw, r)
+ return
+ }
+
+ storedPost, err := a.params.PostStore.GetByID(id)
+
+ if errors.Is(err, post.ErrPostNotFound) {
+ http.Error(rw, "Post not found", 404)
+ return
+ } else if err != nil {
+ apiutil.InternalServerError(
+ rw, r, fmt.Errorf("fetching post with id %q: %w", id, err),
+ )
+ return
+ }
+
+ tplPayload, err := a.postToPostTplPayload(storedPost)
+
+ if err != nil {
+ apiutil.InternalServerError(
+ rw, r, fmt.Errorf(
+ "generating template payload for post with id %q: %w",
+ id, err,
+ ),
+ )
+ return
+ }
+
+ executeTemplate(rw, r, tpl, tplPayload)
+ })
+}
+
+func (a *api) renderPostsIndexHandler() http.Handler {
+
+ renderEditPostHandler := a.renderEditPostHandler(false)
+ tpl := a.mustParseBasedTpl("posts.html")
+ const pageCount = 20
+
+ return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+
+ if _, ok := r.URL.Query()["edit"]; ok {
+ renderEditPostHandler.ServeHTTP(rw, r)
+ return
+ }
+
+ page, err := apiutil.StrToInt(r.FormValue("p"), 0)
+ if err != nil {
+ apiutil.BadRequest(
+ rw, r, fmt.Errorf("invalid page number: %w", err),
+ )
+ return
+ }
+
+ posts, hasMore, err := a.params.PostStore.Get(page, pageCount)
+ if err != nil {
+ apiutil.InternalServerError(
+ rw, r, fmt.Errorf("fetching page %d of posts: %w", page, err),
+ )
+ return
+ }
+
+ tplPayload := struct {
+ Posts []post.StoredPost
+ PrevPage, NextPage int
+ }{
+ Posts: posts,
+ PrevPage: -1,
+ NextPage: -1,
+ }
+
+ if page > 0 {
+ tplPayload.PrevPage = page - 1
+ }
+
+ if hasMore {
+ tplPayload.NextPage = page + 1
+ }
+
+ executeTemplate(rw, r, tpl, tplPayload)
+ })
+}
+
+func (a *api) renderEditPostHandler(isDraft bool) http.Handler {
+
+ tpl := a.mustParseBasedTpl("edit-post.html")
+
+ return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+
+ id := filepath.Base(r.URL.Path)
+
+ var storedPost post.StoredPost
+
+ if id != "/" {
+
+ var err error
+
+ if isDraft {
+ storedPost.Post, err = a.params.PostDraftStore.GetByID(id)
+ } else {
+ storedPost, err = a.params.PostStore.GetByID(id)
+ }
+
+ if errors.Is(err, post.ErrPostNotFound) {
+ http.Error(rw, "Post not found", 404)
+ return
+ } else if err != nil {
+ apiutil.InternalServerError(
+ rw, r, fmt.Errorf("fetching post with id %q: %w", id, err),
+ )
+ return
+ }
+
+ } else if !isDraft {
+ http.Error(rw, "Post ID required in URL", 400)
+ return
+ }
+
+ tags, err := a.params.PostStore.GetTags()
+ if err != nil {
+ apiutil.InternalServerError(rw, r, fmt.Errorf("fetching tags: %w", err))
+ return
+ }
+
+ tplPayload := struct {
+ Post post.StoredPost
+ Tags []string
+ IsDraft bool
+ }{
+ Post: storedPost,
+ Tags: tags,
+ IsDraft: isDraft,
+ }
+
+ executeTemplate(rw, r, tpl, tplPayload)
+ })
+}
+
+func postFromPostReq(r *http.Request) (post.Post, error) {
+
+ p := post.Post{
+ ID: r.PostFormValue("id"),
+ Title: r.PostFormValue("title"),
+ Description: r.PostFormValue("description"),
+ Tags: strings.Fields(r.PostFormValue("tags")),
+ Series: r.PostFormValue("series"),
+ }
+
+ // textareas encode newlines as CRLF for historical reasons
+ p.Body = r.PostFormValue("body")
+ p.Body = strings.ReplaceAll(p.Body, "\r\n", "\n")
+ p.Body = strings.TrimSpace(p.Body)
+
+ if p.ID == "" ||
+ p.Title == "" ||
+ p.Description == "" ||
+ p.Body == "" ||
+ len(p.Tags) == 0 {
+ return post.Post{}, errors.New("ID, Title, Description, Tags, and Body are all required")
+ }
+
+ return p, nil
+}
+
+func (a *api) storeAndPublishPost(ctx context.Context, p post.Post) error {
+
+ first, err := a.params.PostStore.Set(p, time.Now())
+
+ if err != nil {
+ return fmt.Errorf("storing post with id %q: %w", p.ID, err)
+ }
+
+ if !first {
+ return nil
+ }
+
+ a.params.Logger.Info(ctx, "publishing blog post to mailing list")
+ urlStr := a.postURL(p.ID, true)
+
+ if err := a.params.MailingList.Publish(p.Title, urlStr); err != nil {
+ return fmt.Errorf("publishing post to mailing list: %w", err)
+ }
+
+ if err := a.params.PostDraftStore.Delete(p.ID); err != nil {
+ return fmt.Errorf("deleting draft: %w", err)
+ }
+
+ return nil
+}
+
+func (a *api) postPostHandler() http.Handler {
+
+ return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+
+ ctx := r.Context()
+
+ p, err := postFromPostReq(r)
+ if err != nil {
+ apiutil.BadRequest(rw, r, err)
+ return
+ }
+
+ ctx = mctx.Annotate(ctx, "postID", p.ID)
+
+ if err := a.storeAndPublishPost(ctx, p); err != nil {
+ apiutil.InternalServerError(
+ rw, r, fmt.Errorf("storing/publishing post with id %q: %w", p.ID, err),
+ )
+ return
+ }
+
+ a.executeRedirectTpl(rw, r, a.postURL(p.ID, false))
+ })
+}
+
+func (a *api) deletePostHandler(isDraft bool) http.Handler {
+
+ return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+
+ id := filepath.Base(r.URL.Path)
+
+ if id == "/" {
+ apiutil.BadRequest(rw, r, errors.New("id is required"))
+ return
+ }
+
+ var err error
+
+ if isDraft {
+ err = a.params.PostDraftStore.Delete(id)
+ } else {
+ err = a.params.PostStore.Delete(id)
+ }
+
+ if errors.Is(err, post.ErrPostNotFound) {
+ http.Error(rw, "Post not found", 404)
+ return
+ } else if err != nil {
+ apiutil.InternalServerError(
+ rw, r, fmt.Errorf("deleting post with id %q: %w", id, err),
+ )
+ return
+ }
+
+ if isDraft {
+ a.executeRedirectTpl(rw, r, a.draftsURL(false))
+ } else {
+ a.executeRedirectTpl(rw, r, a.postsURL(false))
+ }
+ })
+}
+
+func (a *api) previewPostHandler() http.Handler {
+
+ tpl := a.mustParseBasedTpl("post.html")
+
+ return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+
+ p, err := postFromPostReq(r)
+ if err != nil {
+ apiutil.BadRequest(rw, r, err)
+ return
+ }
+
+ storedPost := post.StoredPost{
+ Post: p,
+ PublishedAt: time.Now(),
+ }
+
+ tplPayload, err := a.postToPostTplPayload(storedPost)
+
+ if err != nil {
+ apiutil.InternalServerError(
+ rw, r, fmt.Errorf("generating template payload: %w", err),
+ )
+ return
+ }
+
+ executeTemplate(rw, r, tpl, tplPayload)
+ })
+}

Please direct all issues, questions, and patches to me@mediocregopher.com.

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