blog/core/blog.go

484 lines
12 KiB
Go

package core
import (
"bytes"
"errors"
"fmt"
"html/template"
"net/http"
"sort"
"strconv"
"strings"
"time"
"github.com/gorilla/mux"
"github.com/kirsle/blog/core/models/comments"
"github.com/kirsle/blog/core/models/posts"
"github.com/kirsle/blog/core/models/users"
"github.com/urfave/negroni"
)
// PostMeta associates a Post with injected metadata.
type PostMeta struct {
Post *posts.Post
Rendered template.HTML
Author *users.User
NumComments int
IndexView bool
Snipped bool
}
// Archive holds data for a piece of the blog archive.
type Archive struct {
Label string
Date time.Time
Posts []posts.Post
}
// BlogRoutes attaches the blog routes to the app.
func (b *Blog) BlogRoutes(r *mux.Router) {
// Public routes
r.HandleFunc("/blog", b.IndexHandler)
r.HandleFunc("/archive", b.BlogArchive)
r.HandleFunc("/tagged", b.Tagged)
r.HandleFunc("/tagged/{tag}", b.Tagged)
r.HandleFunc("/blog/entry/{fragment}", func(w http.ResponseWriter, r *http.Request) {
params := mux.Vars(r)
fragment, ok := params["fragment"]
if !ok {
b.NotFound(w, r, "Not Found")
return
}
b.Redirect(w, "/"+fragment)
})
// Login-required routers.
loginRouter := mux.NewRouter()
loginRouter.HandleFunc("/blog/edit", b.EditBlog)
loginRouter.HandleFunc("/blog/delete", b.DeletePost)
loginRouter.HandleFunc("/blog/drafts", b.Drafts)
loginRouter.HandleFunc("/blog/private", b.PrivatePosts)
r.PathPrefix("/blog").Handler(
negroni.New(
negroni.HandlerFunc(b.LoginRequired),
negroni.Wrap(loginRouter),
),
)
adminRouter := mux.NewRouter().PathPrefix("/admin").Subrouter().StrictSlash(false)
r.HandleFunc("/admin", b.AdminHandler) // so as to not be "/admin/"
adminRouter.HandleFunc("/settings", b.SettingsHandler)
adminRouter.PathPrefix("/").HandlerFunc(b.PageHandler)
r.PathPrefix("/admin").Handler(negroni.New(
negroni.HandlerFunc(b.LoginRequired),
negroni.Wrap(adminRouter),
))
}
// IndexHandler renders the main index page of the blog.
func (b *Blog) IndexHandler(w http.ResponseWriter, r *http.Request) {
b.CommonIndexHandler(w, r, "", "")
}
// Tagged lets you browse blog posts by category.
func (b *Blog) Tagged(w http.ResponseWriter, r *http.Request) {
params := mux.Vars(r)
tag, ok := params["tag"]
if !ok {
// They're listing all the tags.
b.RenderTemplate(w, r, "blog/tags.gohtml", NewVars())
return
}
b.CommonIndexHandler(w, r, tag, "")
}
// Drafts renders an index view of only draft posts. Login required.
func (b *Blog) Drafts(w http.ResponseWriter, r *http.Request) {
b.CommonIndexHandler(w, r, "", DRAFT)
}
// PrivatePosts renders an index view of only private posts. Login required.
func (b *Blog) PrivatePosts(w http.ResponseWriter, r *http.Request) {
b.CommonIndexHandler(w, r, "", PRIVATE)
}
// CommonIndexHandler handles common logic for blog index views.
func (b *Blog) CommonIndexHandler(w http.ResponseWriter, r *http.Request, tag, privacy string) {
// Page title.
var title string
if privacy == DRAFT {
title = "Draft Posts"
} else if privacy == PRIVATE {
title = "Private Posts"
} else if tag != "" {
title = "Tagged as: " + tag
} else {
title = "Blog"
}
b.RenderTemplate(w, r, "blog/index", NewVars(map[interface{}]interface{}{
"Title": title,
"Tag": tag,
"Privacy": privacy,
}))
}
// RenderIndex renders and returns the blog index partial.
func (b *Blog) RenderIndex(r *http.Request, tag, privacy string) template.HTML {
// Get the blog index.
idx, _ := posts.GetIndex()
// The set of blog posts to show.
var pool []posts.Post
for _, post := range idx.Posts {
// Limiting by a specific privacy setting? (drafts or private only)
if privacy != "" {
switch privacy {
case DRAFT:
if post.Privacy != DRAFT {
continue
}
case PRIVATE:
if post.Privacy != PRIVATE && post.Privacy != UNLISTED {
continue
}
}
} else {
// Exclude certain posts in generic index views.
if (post.Privacy == PRIVATE || post.Privacy == UNLISTED) && !b.LoggedIn(r) {
continue
} else if post.Privacy == DRAFT {
continue
}
}
// Limit by tag?
if tag != "" {
var tagMatch bool
if tag != "" {
for _, check := range post.Tags {
if check == tag {
tagMatch = true
break
}
}
}
if !tagMatch {
continue
}
}
pool = append(pool, post)
}
if len(pool) == 0 {
return template.HTML("No blog posts were found.")
}
sort.Sort(sort.Reverse(posts.ByUpdated(pool)))
// Query parameters.
page, _ := strconv.Atoi(r.URL.Query().Get("page"))
if page <= 0 {
page = 1
}
perPage := 5 // TODO: configurable
offset := (page - 1) * perPage
stop := offset + perPage
// Handle pagination.
var previousPage, nextPage int
if page > 1 {
previousPage = page - 1
} else {
previousPage = 0
}
if offset+perPage < len(pool) {
nextPage = page + 1
} else {
nextPage = 0
}
var view []PostMeta
for i := offset; i < stop; i++ {
if i >= len(pool) {
continue
}
post, err := posts.Load(pool[i].ID)
if err != nil {
log.Error("couldn't load full post data for ID %d (found in index.json)", pool[i].ID)
continue
}
// Look up the author's information.
author, err := users.LoadReadonly(post.AuthorID)
if err != nil {
log.Error("Failed to look up post author ID %d (post %d): %v", post.AuthorID, post.ID, err)
author = users.DeletedUser()
}
// Count the comments on this post.
var numComments int
if thread, err := comments.Load(fmt.Sprintf("post-%d", post.ID)); err == nil {
numComments = len(thread.Comments)
}
view = append(view, PostMeta{
Post: post,
Author: author,
NumComments: numComments,
})
}
// Render the blog index partial.
var output bytes.Buffer
v := map[string]interface{}{
"PreviousPage": previousPage,
"NextPage": nextPage,
"View": view,
}
b.RenderPartialTemplate(&output, "blog/index.partial", v, false, nil)
return template.HTML(output.String())
}
// RenderTags renders the tags partial.
func (b *Blog) RenderTags(r *http.Request, indexView bool) template.HTML {
idx, err := posts.GetIndex()
if err != nil {
return template.HTML("[RenderTags: error getting blog index]")
}
tags, err := idx.Tags()
if err != nil {
return template.HTML("[RenderTags: error getting tags]")
}
var output bytes.Buffer
v := struct {
IndexView bool
Tags []posts.Tag
}{
IndexView: indexView,
Tags: tags,
}
b.RenderPartialTemplate(&output, "blog/tags.partial", v, false, nil)
return template.HTML(output.String())
}
// BlogArchive summarizes all blog entries in an archive view.
func (b *Blog) BlogArchive(w http.ResponseWriter, r *http.Request) {
idx, err := posts.GetIndex()
if err != nil {
b.BadRequest(w, r, "Error getting blog index")
return
}
// Group posts by calendar month.
var months []string
byMonth := map[string]*Archive{}
for _, post := range idx.Posts {
// Exclude certain posts
if (post.Privacy == PRIVATE || post.Privacy == UNLISTED) && !b.LoggedIn(r) {
continue
} else if post.Privacy == DRAFT {
continue
}
label := post.Created.Format("2006-01")
if _, ok := byMonth[label]; !ok {
months = append(months, label)
byMonth[label] = &Archive{
Label: label,
Date: time.Date(post.Created.Year(), post.Created.Month(), post.Created.Day(), 0, 0, 0, 0, time.UTC),
Posts: []posts.Post{},
}
}
byMonth[label].Posts = append(byMonth[label].Posts, post)
}
// Sort the months.
sort.Sort(sort.Reverse(sort.StringSlice(months)))
// Prepare the response.
result := []*Archive{}
for _, label := range months {
sort.Sort(sort.Reverse(posts.ByUpdated(byMonth[label].Posts)))
result = append(result, byMonth[label])
}
v := NewVars(map[interface{}]interface{}{
"Archive": result,
})
b.RenderTemplate(w, r, "blog/archive", v)
}
// viewPost is the underlying implementation of the handler to view a blog
// post, so that it can be called from non-http.HandlerFunc contexts.
// Specifically, from the catch-all page handler to allow blog URL fragments
// to map to their post.
func (b *Blog) viewPost(w http.ResponseWriter, r *http.Request, fragment string) error {
post, err := posts.LoadFragment(fragment)
if err != nil {
return err
}
// Handle post privacy.
if post.Privacy == PRIVATE || post.Privacy == DRAFT {
if !b.LoggedIn(r) {
b.NotFound(w, r)
return nil
}
}
v := NewVars(map[interface{}]interface{}{
"Post": post,
})
b.RenderTemplate(w, r, "blog/entry", v)
return nil
}
// RenderPost renders a blog post as a partial template and returns the HTML.
// If indexView is true, the blog headers will be hyperlinked to the dedicated
// entry view page.
func (b *Blog) RenderPost(p *posts.Post, indexView bool, numComments int) template.HTML {
// Look up the author's information.
author, err := users.LoadReadonly(p.AuthorID)
if err != nil {
log.Error("Failed to look up post author ID %d (post %d): %v", p.AuthorID, p.ID, err)
author = users.DeletedUser()
}
// "Read More" snippet for index views.
var snipped bool
if indexView {
if strings.Contains(p.Body, "<snip>") {
parts := strings.SplitN(p.Body, "<snip>", 2)
p.Body = parts[0]
snipped = true
}
}
p.Body = strings.Replace(p.Body, "<snip>", "<div id=\"snip\"></div>", 1)
// Render the post to HTML.
var rendered template.HTML
if p.ContentType == string(MARKDOWN) {
rendered = template.HTML(b.RenderTrustedMarkdown(p.Body))
} else {
rendered = template.HTML(p.Body)
}
meta := PostMeta{
Post: p,
Rendered: rendered,
Author: author,
IndexView: indexView,
Snipped: snipped,
NumComments: numComments,
}
output := bytes.Buffer{}
err = b.RenderPartialTemplate(&output, "blog/entry.partial", meta, false, nil)
if err != nil {
return template.HTML(fmt.Sprintf("[template error in blog/entry.partial: %s]", err.Error()))
}
return template.HTML(output.String())
}
// EditBlog is the blog writing and editing page.
func (b *Blog) EditBlog(w http.ResponseWriter, r *http.Request) {
v := NewVars(map[interface{}]interface{}{
"preview": "",
})
var post *posts.Post
// Are we editing an existing post?
if idStr := r.URL.Query().Get("id"); idStr != "" {
id, err := strconv.Atoi(idStr)
if err == nil {
post, err = posts.Load(id)
if err != nil {
v.Error = errors.New("that post ID was not found")
post = posts.New()
}
}
} else {
post = posts.New()
}
if r.Method == http.MethodPost {
// Parse from form values.
post.ParseForm(r)
// Previewing, or submitting?
switch r.FormValue("submit") {
case "preview":
if post.ContentType == string(MARKDOWN) {
v.Data["preview"] = template.HTML(b.RenderTrustedMarkdown(post.Body))
} else {
v.Data["preview"] = template.HTML(post.Body)
}
case "post":
if err := post.Validate(); err != nil {
v.Error = err
} else {
author, _ := b.CurrentUser(r)
post.AuthorID = author.ID
err = post.Save()
if err != nil {
v.Error = err
} else {
b.Flash(w, r, "Post created!")
b.Redirect(w, "/"+post.Fragment)
}
}
}
}
v.Data["post"] = post
b.RenderTemplate(w, r, "blog/edit", v)
}
// DeletePost to delete a blog entry.
func (b *Blog) DeletePost(w http.ResponseWriter, r *http.Request) {
var post *posts.Post
v := NewVars(map[interface{}]interface{}{
"Post": nil,
})
var idStr string
if r.Method == http.MethodPost {
idStr = r.FormValue("id")
} else {
idStr = r.URL.Query().Get("id")
}
if idStr == "" {
b.FlashAndRedirect(w, r, "/admin", "No post ID given for deletion!")
return
}
// Convert the post ID to an int.
id, err := strconv.Atoi(idStr)
if err == nil {
post, err = posts.Load(id)
if err != nil {
b.FlashAndRedirect(w, r, "/admin", "That post ID was not found.")
return
}
}
if r.Method == http.MethodPost {
post.Delete()
b.FlashAndRedirect(w, r, "/admin", "Blog entry deleted!")
return
}
v.Data["Post"] = post
b.RenderTemplate(w, r, "blog/delete", v)
}