Cleaning the output of a converter

18 Nov 2011

When I worked at a small web design company, we often had clients bringing us a MS Word, Excel, or PDF file that must be published on web. Not as a downloadable file, but as a web page integrated into their site.

Microsoft Word certainly can save files in HTML, but the resulting code was bloated and different from our design. What we needed was a simple HTML that our designer could edit and style. How could Aba S&R help us?

Here is a DOC file saved in HTML:

<h3 align=center style='text-align:center;'><b><span style='font-size:10.0pt;font-family:"Arial";'>Lorem ipsum</span></b></h3>

<p class=Normal align=justify style='text-indent:14.0pt;text-align:justify;'><span style='font-family:"Times New Roman";'>Lorem ipsum dolor sit <i>amet,</i> consectetur adipisicing elit.</span></p>

We need to remove all attributes and <span> tags:

<h3><b>Lorem ipsum</b></h3>

<p>Lorem ipsum dolor sit <i>amet,</i> consectetur adipisicing elit.</p>

The following replacements can be used:

Search for: <(p|h1|h2|h3) [^>]*>
Replace with: <\1>

Search for: <span [^>]*>
Replace with: (nothing)

Search for: </span>
Replace with: (nothing)

[^>]* matches everything up to the next closing angle bracket >, and \1 means the text inside the first parentheses (in our case, the tag name).

Generally, I often used Aba to clean the output of a converter. For one client, I had to convert dozens of PDF files with technical specifications to HTML. There was a lot of formatting (subscripts, superscripts, tables), so I could not simply copy-and-paste it. There also were errors, for example, the letter O instead of zero in subscripts. Without Aba, I would not clean this mess.

Is it a bad practice?

Two redditors criticized my previous post about using regular expressions to replace HTML tags.

I fully agree that regexes should never be used to parse an arbitrary HTML code, for example, an HTML code entered by user. Never do this in your scripts; it's unreliable and insecure.

But what if you need to replace all relative links (/blog/) in your own code with absolute links (http://www.example.com/blog/), because you are moving some parts of your site to a subdomain (http://myproduct.example.com). Would you craft a script that parses your HTML code (carefully skipping <?php tags — Python's HTMLParser cannot do that), searches for all <a> tags with the href attribute, replaces the links, and saves the result to a file?

Or would you toss off a regex in a search-and-replace tool?

Stop pasting your data into dubious cloud-based tools. Aba Search and Replace is your Swiss army knife for regular expression search, fast and safe updates across multiple files, and various conversions, with all your data staying on your computer. Built for power users, developers, testers, and analysts. Hand-coded in the EU.