How can I strip whitespace and newlines with Mako templates? My 12362 line HTML file is killing IE

Question

I'm using the Mako template system in my Pylons website and am having some issues with stripping whitespace.

My reasoning for stripping whitespace is the generated HTML file comes out as 12363 lines of code. This, I assume, is why Internet Explorer is hanging when it tries to load it.

I want to be able to have my HTML file look nice and neat so I can make changes to it with ease and have the generated output look as ugly and messy as required to cut down on filesize and memory usage.

The Mako documentation http://www.makotemplates.org/docs/filtering.html says you can use the trim flag but that doesn't seem to work. Example code:

<div id="content">
    ${next.body() | trim}
</div>

The only way I've been able to strip the newlines is to add a \ (backslash) to the end of each line. This is rather annoying when coding the views and I'd prefer to have a centralized solution.

How do I remove the whitespace/newlines ?

Answer 1

I'm guessing that the trim filter is treating your html as a single string, and only stripping the leading and trailing whitespace characters. You want it to strip whitespace from every line. I would create a filter and iterate over each line.

<%!
    def better_trim(html):
        clean_html = ''
        for line in html:
            clean_html += line.strip()
        return clean_html
%>

<div id="content">
    ${next.body() | better_trim}
</div>

Answer 2

I don't believe IE hanging is due to the file size. You have probably just found a combination of markup that hits an IE bug that causes it to freeze. Try trimming down you document until the freeze no longer happens to isolate the offending piece of markup pattern (and then avoid the markup pattern), or try changing the markup until this no longer happens.

Another good thing to do would be to run your page through HTML validator and fixing any issues reported.