Detecting empty elements with XML::Reader

[jfieber]

The Reader pull-parser doesn't expose a way to determine if an element is empty when there is no separate end tag (), since no end element is encountered (or synthesized). I presume some call to xmlTextReaderIsEmptyElement is in order.

[flavorjones]

Can you please write up a (failing) unit test expressing exactly what you'd like to see? Linking to a gist from this ticket would be perfect.

[flavorjones]

Ping: jflieber -- is this still needed?

[jfieber]

Yes, I was pulled in another direction for awhile but can get back to this.

[jfieber]

I've dug into this and clumsy handling of empty elements appears to be a "feature" of the libxml2 reader. See http://xmlsoft.org/xmlreader.html#Extracting

Exposing IsEmptyElement via nokogiri would be a nice-to-have -- to know that an end element won't be in the pipeline for a given start element -- but empty elements can be identified by the depth of whatever follows the start element.

So, exposing the IsEmptyElement is a wishlist item, but not a bug.

[flavorjones]

Can you please write up a (failing) unit test expressing exactly what you'd like to see? Linking to a gist from this ticket would be perfect.

[vladzloteanu]

I also believe this would be nice to have. http://stackoverflow.com/questions/2775307/nokogiri-pull-parser-nokogirixmlreader-issue-with-self-closing-tag . Basically, using the Reader#read method, i would like to know if i'm on a <tag> or on a <tag/> node.

[flavorjones]

I'm glad everyone agrees this is a nice feature to have. High five!

P.S. Can you please write up a (failing) unit test expressing exactly what you'd like to see? Linking to a gist from this ticket would be perfect.

P.P.S. Srsly, peepul. Failing unit test.

[vladzloteanu]

http://gist.github.com/392060

[flavorjones]

Awesome! Thank you.

What would everyone think about making the method name be "empty?" instead of "empty_element?" ? The precedent is in Nokogiri::HTML::ElementDescription (as well as String, Array, Hash, etc.). Plus it means less typing. :)

[vladzloteanu]

You're right. I'm OK with it. Q: because it's more generic, what will it return for other node types? (false or undefined?). EG </tag> is empty?

[flavorjones]

Hum. Maybe we should go for a more semantic method name, like self_closing??

[johndouthat]

I second self_closing? .

[tenderlove]

adding Reader#empty_element? and Reader#self_closing? closed by 52a2473