Fix casing in :title and add :slug for automatic downcasing in URLs

[rebornix]

The only difference between slug and title is that uppercase letters are not converted to their lowercase counterparts in slug. After adding this property, the final permalink of _posts/2015-10-27-Jekyll.md with permalink style /:year/:month/:day/:slug will be /2015/10/27/Jekyll/.

This pr is related to issue #4072 and it's my first time writing ruby, correct me if I made anything wrong.

[envygeeks]

I'm on the fence with this, I don't know if the rest of @jekyll/core will be but surely to me a slug is the one that is normalized, so this is the flip of that. I would much rather slug to be something like "cased_title" or something to that effect.

[rebornix]

Actually the word slug confuses me all the time, when we are trying to extract the title from file name (see code here),

m, cats, date, slug, ext = *relative_path.match(DATE_FILENAME_MATCHER)

we are naming the variable as slug and it's not normalized.

@envygeeks your suggestion is great, cased_title is more intuitive and accurate. I'll take your advice if others are Okay with this name.

[parkr]

What is most backwards-compatible? I thought :title was Cased and :slug was uncased.

[envygeeks]

In theory if I were programming an app (a blog) that was in Rails or Lotus slug would be the one that downcases, normalizes and transforms and title would be the one that keeps case and does the minimal of normalizing to ensure that a path doesn't break.

[parkr]

What did Jekyll do before, though? That's what I'm asking. It sounds like 3.0 changed this behaviour, and I'm not sure it did it for any good reason other than my own laziness or bad testing.

[rebornix]

title was Cased before 3.0, but after upgrade to 3.0, it became lowercase now. As I mentioned in #4072, any blog which contains posts like "2015-10-27-Cased.md" will break. It's a breaking change.

[parkr]

Ok so let's make :title cased and :slug uncased.

[rebornix]

In old version Jekyll, we haven't moved url_placeholders from post.rb to document.rb, we assigned slug in post.rb to title

def url_placeholders
      {
        :year        => date.strftime("%Y"),
        :month       => date.strftime("%m"),
        :day         => date.strftime("%d"),
        :hour        => date.strftime("%H"),
        :minute      => date.strftime("%M"),
        :second      => date.strftime("%S"),
        :title       => slug,

while in post.rb, slug is just the title we extract from filename.

def process(name)
      m, cats, date, slug, ext = *name.match(MATCHER)
      self.date = Utils.parse_date(date, "Post '#{relative_path}' does not have a valid date in the filename.")
      self.slug = slug
      self.ext = ext
    end

But at that time, we don't even have slugify. So I suppose this issue is introduced by utils.slugify.

I'll update my pr ASAP.

[rebornix]

I've updated my pr to make :title cased and add uncased :slug for user customization, pls help review 😄

[envygeeks]

That's a pretty complete pull request. I'm 👍 but just one request, can you squash it?

[rebornix]

@envygeeks it's done. Can't wait to see this commit gets merged.

[rebornix]

@parkr does this PR look good to you?

[Sneezry]

Hey @envygeeks @parkr

I have the same issue when I build my site with the latest version Jekyll 3.0, and all my links are broken, please merge this pr as soon as possible to solve my problem, thx.

Zhe Li

[parkr]

should this be slugify(data['slug'], cased: true) perchance?

[parkr]

we can change the api later, i guess.

[rebornix]

@parkr named parameter is a better solution, thanks for advice!

BTW, you may want to take a look at issue #4135 , users are complaining about their underscore are replaced by hyphen, maybe someday users would say they want their ~ back. Should we use Pretty mode here for :title, seems Pretty mode [^[:alnum:]._~!$&'()+,;=@]+ is designed to handle this kind of issue.

[parkr]

Yeah that sounds good.

[parkr]

@parkr does this PR look good to you?

@rebornix Cucumber tests fail :(

[rebornix]

@parkr such a silly mistake :( . Fixed now.

[Stargator]

👍 @rebornix For a first go at Ruby you did great! I'm learning Ruby as well.

[parkr]

^^ agreed!

[yous]

Hi, I used my permalink setting as /:year/:month/:day/:title/. Then after upgrading Jekyll from 3.0.0 to 3.0.1, the links are changed, for example, from /2013/02/18/ios-6-1-music-album-shuffle/ to /2013/02/18/ios-6.1-music-album-shuffle/. Note the 6-1 and 6.1. For the consistency, I need to change the permalink setting to /:year/:month/:day/:slug/.

I agree to the direction of change, making title pretty. But I think this might be considered as a breaking change, since it can break some sites silently as URLs are delicate. I see this pull request as adding :slug and changing :title, not fixing it.

[rebornix]

@yous Actually if you are upgrading Jekyll from 2.x to 3.0.1, you will not notice any breaking change. From my perspective, 3.0.1 is like a quick turnaround for some 3.0.0 unplanned breaking change.

BTW, instread of just making title pretty, I add slug for anyone who wants to keep up with Jekyll slugify trend. You got the chance to make everything correct, right?

People in community are trying to make slugify customizable, you might be interested.

[yous]

@rebornix Oops, I hadn't noticed the change when I upgrade Jekyll 2.x to 3.0.0.pre.x. Well... it seems I need more tests. Thanks for pointing it out!

[envygeeks]

If it's not noted in our upgrading docs that @parkr just released please file a ticket so we can update those docs to mention that.