Select text between two tags

[MikeB]

Hi,

How can I select the line in the text between two anchors?

For instance, we have the sentence: «I love <some_anchor>to visit old Europe cities</some_anchor> on holidays».

So, I want to select and store in internal table the text, located between some tag, e.g. <some_anchor>.

Should I use RegEx (regular expressions) or the regular pattern is enough?

And how can I do it?

Thanks.

[Former Member]

It depends... are you trying to match just one specific tag pair, or are you trying to capture some XML/HTML type text? It's generally accepted that you can't parse html with regex

Regex will work, but be careful with it... try program DEMO_REGEX_TOY to mess around with your regular expressions. Consider the following:

DATA result TYPE match_result_tab.
 DATA line LIKE LINE OF result.
 DATA sub TYPE submatch_result.
 DATA text TYPE string.
 text  = '<tag>this</tag>asdfasdf</tag>asdf<tag>all</tag></tag>as<tag>matches</tag>'.
 FIND ALL OCCURRENCES OF REGEX '<tag>((?:[^<]|<?!/tag>)*)</tag>' IN text IGNORING CASE RESULTS result.
 LOOP AT result INTO line.
   LOOP AT line-submatches INTO sub.
     WRITE: / text+sub-offset(sub-length).
   ENDLOOP.
 ENDLOOP.

the result of this is:

this

all

matches

the regex bit '<tag>((?:[^<]|<?!/tag>)*)</tag>' is slightly confusing looking because regex is lazy: it will not stop matching a sub query until it finds the last tag in the text. In my example, regex <tag>(.*)</tag> would match

'<tag>this</tag>asdfasdf</tag>asdf<tag>all</tag></tag>as<tag>matches</tag>'

[MikeB]

Hi, Jorg

I need to care with all pairs of tags separately, I mean, if we have <SPAN STYLE="…">…<SPAN STYLE="…">…</SPAN></SPAN>, so we need to care of both SPAN tags.

Also, I've paid attention, that in text, you proposed as example:

text  = '<tag>this</tag>asdfasdf</tag>asdf<tag>all</tag></tag>as<tag>matches</tag>'.

There is an issue with hierarchy of tags, such as the third tag «</tag>» is a closing tag, but there is no needed open tag in order to build correct tag hierarchy.

[Former Member]

My example only matches "<tag>", and not "<tag ..something else..>". You'll need to come up with a bit more elaborate opening tag regex.

Yeah, nested tags is an issue. Parsing html with regex is not a good idea.

[Former Member]

I just thought of something... perhaps the XML parsing classes can help you out. That's all tags as well.

[MikeB]

Hi, I solved my issue.

Detailed explanation of the subject published in separate post on my blog.

«Regular expressions in ABAP. Approach to HTML processing with regex» —

http://scn.sap.com/community/abap/blog/2012/10/08/a-regular-expression-regex-approach-to-html-proces...