/*
Package post provides the data and behavior for the fundamental atomic
unit of a site: a post. Posts are represented as text files, then converted to HTML and other formats
*/
package post
import (
"adammathes.com/snkt/config"
"adammathes.com/snkt/render"
"adammathes.com/snkt/text"
"adammathes.com/snkt/vlog"
"github.com/russross/blackfriday"
"io/ioutil"
"log"
"os"
"path"
"strconv"
"strings"
"time"
)
var Template = "post"
type Post struct {
// Representations of the entire post text
Raw []byte
Unparsed string
// Metadata
Meta map[string]string
SourceFile string
Title string `json:"title"`
Permalink string `json:"permalink"`
Time time.Time
Year int
Month time.Month
Day int
InFuture bool
// Content text -- raw, unprocessed, unfiltered markdown
Text string
// Content text -- processed into HTML via markdown and other filters
Content string
// Content with sources and references resolved to absolute URLs
AbsoluteContent string
// Post following chronologically (later)
Next *Post
// Post preceding chronologically (earlier)
Prev *Post
// Precomputed dates as strings
Date string
RssDate string
FileInfo os.FileInfo
Site sitemeta
}
type sitemeta interface {
GetURL() string
GetTitle() string
}
type Posts []*Post
func (posts Posts) Len() int {
return len(posts)
}
func (posts Posts) Less(i, j int) bool {
return posts[i].Time.Before(posts[j].Time)
}
func (s Posts) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func NewPost(s sitemeta) *Post {
var p Post
p.Site = s
return &p
}
/*
Read reads a post from file fi, and parses it into the Post struct, performing any work needed to fully populate the struct
*/
func (p *Post) Read(fi os.FileInfo) {
p.Meta = make(map[string]string)
p.FileInfo = fi
p.SourceFile = p.FileInfo.Name()
var err error
p.Raw, err = ioutil.ReadFile(path.Join(config.Config.TxtDir, fi.Name()))
if err != nil {
log.Println(err)
}
p.Unparsed = string(p.Raw)
p.parse()
}
/*
Parse parses the metadata prefix from the top of the post file's raw bytes, and puts the rest in the text segment. Meta is a name:value mapping
Title, date and other metadata are derived
*/
func (p *Post) parse() {
//
// Text + Meta[string][string]
//
p.splitTextMeta()
//
// Title
//
p.Title = p.Meta["title"]
// Use filename as backup fi we have no explicit title
if p.Title == "" {
p.Title = p.SourceFile
}
//
// Dates
//
// we only deal with yyyy-mm-dd [some legacy dates from my archives have times tacked on]
// TODO: recover from empty dates/titles
// TODO: probably should actually use times when present and clean up my archives
var date_str = ""
ds := strings.Fields(p.Meta["date"])
if len(ds) > 0 {
date_str = ds[0]
}
if date_str == "" {
p.Time = p.FileInfo.ModTime()
vlog.Printf("no date field in post %s, using file modification time\n", p.SourceFile)
} else {
var err error
p.Time, err = time.ParseInLocation("2006-1-2", date_str, time.Local)
if err != nil {
// fallback is to use file modtime
// should use create time but that doesn't seem to be in stdlib
// TODO: figure out how to use file birth time
vlog.Printf("no valid date parsed for post %s, using file modification time\n", p.SourceFile)
p.Time = p.FileInfo.ModTime()
}
}
p.Year, p.Month, p.Day = p.Time.Date()
/* golang date format refresher
1 2 3 4 5 7 6
Mon Jan 2 15:04:05 MST 2006 */
p.Date = p.Time.Format("January 2, 2006")
p.RssDate = p.Time.Format("Mon, 2 Jan 2006 15:04:05 GMT")
p.InFuture = time.Now().Before(p.Time)
p.Permalink = p.GenPermalink()
//
// Content
//
p.Content = string(p.Filter([]byte(p.Text)))
p.AbsoluteContent = render.ResolveURLs(p.Content, p.Site.GetURL())
}
/*
splitText splits up p.Unparsed into p.Text and p.Meta[attr][value]
*/
func (p *Post) splitTextMeta() {
SEPARATOR := ":"
lines := strings.Split(p.Unparsed, "\n")
for _, line := range lines {
if !strings.Contains(line, SEPARATOR) {
break
}
splitdex := strings.Index(line, SEPARATOR)
attr := strings.ToLower(strings.TrimSpace(line[0:splitdex]))
value := strings.TrimSpace(line[splitdex+1:])
p.Meta[attr] = value
}
p.Text = strings.Join(lines[len(p.Meta):], "\n")
}
func (p *Post) ParseFmt(s string) string {
// TODO: document and add strftime like formats
s = strings.Replace(s, "%Y", strconv.Itoa(p.Year), -1)
s = strings.Replace(s, "%M", strconv.Itoa(int(p.Month)), -1)
s = strings.Replace(s, "%D", strconv.Itoa(p.Day), -1)
s = strings.Replace(s, "%F", p.CleanFilename(), -1)
s = strings.Replace(s, "%T", p.CleanTitle(), -1)
s = strings.Replace(s, "$Y", strconv.Itoa(p.Year), -1)
s = strings.Replace(s, "$M", strconv.Itoa(int(p.Month)), -1)
s = strings.Replace(s, "$D", strconv.Itoa(p.Day), -1)
s = strings.Replace(s, "$F", p.CleanFilename(), -1)
s = strings.Replace(s, "$T", p.CleanTitle(), -1)
s = strings.Replace(s, ".File", p.CleanFilename(), -1)
s = strings.Replace(s, ".Title", p.CleanTitle(), -1)
s = strings.Replace(s, ".Year", strconv.Itoa(p.Year), -1)
s = strings.Replace(s, ".Month", strconv.Itoa(int(p.Month)), -1)
s = strings.Replace(s, ".Day", strconv.Itoa(p.Day), -1)
return s
}
func (p *Post) CleanFilename() string {
return text.SanitizeFilename(text.RemoveExt(p.SourceFile))
}
func (p *Post) CleanTitle() string {
return text.SanitizeFilename(p.Title)
}
/*
GenPermalink generates the permalink for the post given the PermalinkFmt format specified in the configuration file.
*/
func (p *Post) GenPermalink() string {
pl := config.Config.PermalinkFmt
return p.ParseFmt(pl)
}
/*
Target returns a string representing the file system location to write the output file representing the post.
*/
func (p Post) Target() string {
pf := config.Config.PostFileFmt
return path.Join(config.Config.HtmlDir, p.ParseFmt(pf))
}
/*
Render returns the post rendered as HTML via the post template with Post and Site as context.
*/
func (p Post) Render() []byte {
data := struct {
Post interface{}
Site interface{}
}{&p, &p.Site}
return render.Render(Template, data)
}
/*
Filter runs the text through filters defined by render.Filter and marddown, returning text suitable for HTML output.
*/
func (p *Post) Filter(txt []byte) []byte {
txt = render.Filter(txt)
txt = blackfriday.MarkdownCommon(txt)
return txt
}
/*
Limit returns a slice of Posts up to the int limit provided. If the limit is larger than the slice, it just returns the whole slice.
*/
func (posts Posts) Limit(limit int) Posts {
if len(posts) < limit {
return posts
} else {
return posts[0:limit]
}
}
