ABAP HTML Diff
Library to highlight the content difference between two HTML strings (htmldiff).
This is a diffing library that understands HTML. Best suited for cases when you want to show a diff of user-generated HTML.
An enhancement was made so the code can also produce the diff of two texts (tags are treated like text).
NO WARRANTIES, MIT License
Prerequisites
SAP Basis 7.4 or higher
Usage
Diffing HTML
The following produces the diff of two example HTML snippets:
DATA:
lv_original TYPE string,
lv_modified TYPE string,
lv_diff TYPE string,
li_htmldiff TYPE REF TO zif_htmldiff.
lv_original = '\n'
&& ' <p>First paragraph.</p>\n'
&& ' <ul>\n'
&& ' <li>Item A</li>\n'
&& ' <li>Item B</li>\n'
&& ' <li>Item C</li>\n'
&& ' </ul>\n'
&& ' <img src="previous.jpg">\n'
&& ' <span>This is some interesting text.</span>\n'.
lv_modified = '\n'
&& ' <p>First paragraph.</p>\n'
&& ' <ul>\n'
&& ' <li>Item A</li>\n'
&& ' <li>Item B</li>\n'
&& ' <li>Item D</li>\n'
&& ' </ul>\n'
&& ' <img src="next.jpg">\n'
&& ' <span>This is some new text.</span>\n'.
REPLACE ALL OCCURRENCES OF '\n' IN lv_original WITH cl_abap_char_utilities=>newline.
REPLACE ALL OCCURRENCES OF '\n' IN lv_modified WITH cl_abap_char_utilities=>newline.
li_htmldiff = zcl_htmldiff=>create( ).
lv_diff = li_htmldiff->htmldiff(
iv_before = lv_original
iv_after = lv_modified
iv_with_img = abap_false ).
Result:
<p>First paragraph.</p>
<ul>
<li>Item A</li>
<li>Item B</li>
<li>Item <del>C</del><ins>D</ins></li>
</ul>
<img src='previous.jpg'><img src='next.jpg'>
<span>This is some <del>interesting</del><ins>new</ins> text.</span>
By setting the image parameter to true, you can also mark changed images as deletions or insertions:
lv_diff = li_htmldiff->htmldiff(
iv_before = lv_original
iv_after = lv_modified
iv_with_img = abap_true ).
Result:
<p>First paragraph.</p>
<ul>
<li>Item A</li>
<li>Item B</li>
<li>Item <del>C</del><ins>D</ins></li>
</ul>
<del><img src='previous.jpg'></del><ins><img src='next.jpg'></ins>
<span>This is some <del>interesting</del><ins>new</ins> text.</span>
There are a few other options you can set in the constructor/create statement:
iv_inserts: Show <ins> tags (default: on)iv_deletes: Show <del> tags (default: on)iv_css_classes: Add CSS classes to <ins> and <del> tags (default: off)iv_support_chinese: Treat Chinese characters as individual words (default: off)
Using CSS classes, the result will distinguish between inserts (class diffins), deletes (class diffdel), and updates (class diffmod).
See the test classes for more examples.
Diffing Text
The following produces the diff of two example text snippets:
DATA:
lv_original TYPE string,
lv_modified TYPE string,
lv_diff TYPE string,
li_htmldiff TYPE REF TO zif_htmldiff.
lv_original = 'a c'.
lv_modified = 'a b c'.
lv_diff = li_htmldiff->textdiff(
iv_before = lv_original
iv_after = lv_modified ).
Result:
a <ins>b </ins>c
Example 2:
lv_original = 'a b c'.
lv_modified = 'a c'.
lv_diff = li_htmldiff->textdiff(
iv_before = lv_original
iv_after = lv_modified ).
Result:
a <del>b </del>c
Styling
Here's an examle for styling the insertions and deletions using CSS.
/* CSS for <ins> and <del> tags */
ins { background-color: #ddffdd; }
ins img { border-color: #ddffdd; }
del { background-color: #ffdddd; }
del img { border-color: #ffdddd; }
With the CSS class option, use the following:
/* CSS for insert, delete, and modify classes */
.diffins { background-color: #ddffdd; }
.diffdel { background-color: #ffdddd; }
.diffmod { background-color: #ffffdd; }
Installation
Install html-diff as a global module in your system using apm.
or
Specify the html-diff module as a dependency in your project and import it to your namespace using apm.
Contributions
All contributions are welcome! Read our Contribution Guidelines, fork this repo, and create a pull request.
You can install the developer version of ABAP HTML Diff using abapGit by creating a new online repository for https://github.com/abapPM/ABAP-HTML-Diff.
Recommended SAP package: $HTML-DIFF
Attribution
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