don't create IDs for headers by default

[jonathanong]

since we can create custom renderers now, i don't see the point of including this by default. the default renderer should be minimal and simple, and it would close plenty of issues surrounding this issue.

[Feder1co5oave]

What issues? If you want to avoid id collisions, just use the headerPrefix option.
I find that headers with ID come handy when I need to reference different parts of the same document.

[jonathanong]

because it's another option and an opinionated feature. i don't want it at all. easier if it wasn't supported.

[kennethormandy]

I agree with this. It’s nice to have the option, but I think it makes more sense that it’s opt-in.

[ChrisWren]

I agree in 0.4.0 release it should be removed.

[Feder1co5oave]

I'd like to share my implementation of the header renderer with ID creation:

myRenderer.heading = function(text, level, raw, options) {
    return '<h'
     + level
     +' id="'
     + options.headerPrefix
     + raw.toLowerCase().replace(/[^\wàùòèéì]+/g, '-').replace(/^\-+|\-+$/g, '')
     + '">'
     + text
     + '</h'
     + level
     + '>\n';
}

It is useful to keep letters with accents (I included the Italian ones) and removes any leading or trailing dashes:

$ bin/marked 
### `$ cat LICENSE`
<h3 id="cat-license-"><code>$ cat LICENSE</code></h3>

$ bin/marked 
### Definizione di probabilità assiomatica (Kolmogorov)
<h3 id="definizione-di-probabilità-assiomatica-kolmogorov">Definizione di probabilità assiomatica (Kolmogorov)</h3>

[ArmorDarks]

I also think it should be switched off by default, since it injects unexpected ids into markup and seems like pretty much opinionated option.

Besides, it doesn't work with non-latin headers, which results in quite horrible ids

[the0neWhoKnocks]

+1

It's far too easy to create issues on a page with dynamically generated ids. At the least, if it's not going to be removed, it should be automatically prefixed with marked- or md-. Something to set it apart from other ids that may already be on the page. If a plugin or framework is asserting it's opinions on a dev, it should at least do so transparently & in a non-conflicting manor.

Aside from that, and not being able to easily add new custom token rules (not just overriding current ones); this is some fine code and has saved me time implementing a new MD editor. So thank you for your efforts, they are appreciated.

[brunowego]

+1

[fedesilvaponte]

+1

[Dafrok]

+1

[luketeaford]

Would love this feature -- the ID should be optional because there are many scenarios where it is obtrusive.

[ahuglajbclajep]

This is easy to achieve.
If node >=4.0.0,

const marked = require('marked');

const renderer = new marked.Renderer();
renderer.heading = (text, level) => `<h${level}>${text}</h${level}>`;
marked.setOptions({renderer});

Have a nice Markdown life!

[joshbruce]

See #956

If you are still interested in this, comment.

[alberto56]

Just sharing how I obtain IDs in the browser

            const renderer = new marked.Renderer();
            renderer.heading = function(text, level) {
              const id = text.text.toLowerCase().replace(/[^a-zA-Z0-9]+/g, '-');
              return `<h${text.depth} id="${id}">${text.text}</h${text.depth}>`;
            }
            marked.setOptions({renderer});