Regex in ABAP, HTML processing in ABAP with regular expressions

[MikeB]

Recently I faced a problem to proceed HTML-code and replace some CSS-expression with HTML tag analog. For instance, font-weight: bold; property inside of <span> tag value must be replaced with <strong> HTML-tag. One of the ways to solve this problem is to use regular expressions in ABAP. Further I'm going to explain my solution with detailed code of ABAP regex.

First-of-all we need to detect <span style="…"> block, where there is a font-weight property, and then surround the content of this block with HTML <strong> tag.

1. REPLACE ALL OCCURRENCES OF REGEX '(font-weight:[^>]*>)([^♦]*)(♦)(</span>)'


2. IN html_string WITH '$1<strong>$2</strong>$3$4' IGNORING CASE.

You may ask about „♦“ symbol, I'll pay attention to it at the end of this post.
 

Some comments:

• Brackets „(…)“ allow to us to define an block, that can be placed or deleted in specific place in result of regex.


• Expression „[^>]*“ will get the string until the char „>“, the same logic with „[^♦]*“.


• By using „$“ char and number we can arrange and put concrete block to the specific place.

Now, when we have found the relevant <span> block and surrounded its content with wanted tag we can remove font-weight property from <span style="…"> block.

1. REPLACE ALL OCCURRENCES OF REGEX '(font-weight:[^;]*;)'


2. IN html_string WITH '' IGNORING CASE.

That's all. We just replaced font-weight property in <span> block with <strong> HTML-tag.

Now, it's a turn to explain the meaning of „♦“ symbol. Actually, it's a kind of workaround for the case of nested HTML-tags inside of span-block, e.g. <span style="…">…<em>…</em>…</span>.

In order to detect the end of span-block content and not the end of any nested tag I add an anchor — „♦“ symbol before </span> and use this anchor in my regex.

At the and I have to remove this anchor with the following regex:

1. REPLACE ALL OCCURRENCES OF REGEX '♦'


2. IN html_string WITH '' IGNORING CASE.

 

Final code:

1. " set workaround for nested tags case


2. " I'm using a special char '♦' in order to deal


3. " with case when we have a nested HTML tags and we want to know


4. " the real end of the string that we want to surround


5. " with basic HTML tag


6. REPLACE ALL OCCURRENCES OF REGEX '</span>'


7. IN html_string WITH '♦</span>' IGNORING CASE.




9. " surround bold (FONT-WEIGHT: bold) text with HTML's STRONG tag


10. REPLACE ALL OCCURRENCES OF REGEX '(font-weight:[^>]*>)([^♦]*)(♦)(</span>)'


11. IN html_string WITH '$1<strong>$2</strong>$3$4' IGNORING CASE.




13. " remove unneeded CSS-style font-weight property


14. REPLACE ALL OCCURRENCES OF REGEX '(font-weight:[^;]*;)'


15. IN html_string WITH '' IGNORING CASE.




17. " delete workaround for nested tags case


18. REPLACE ALL OCCURRENCES OF REGEX '♦'


19. IN html_string WITH '' IGNORING CASE.

 

Additional links:

• Regular-Expressions.info


• Regular Expression Processing in ABAP

P.S. If you know the better way to solve this problem, feel free to share your experience!