Add option to include images as inline data

[dov]

I'm currently using npm install inliner for embedding images in an html file into the document. This step is necessary for disconnecting the html from external references.

It would be nice if premailer also had this option.

[peterbe]

You mean, base64 inlining? Like, <img src="data:image/png;base64,xxxxxx">.

Perhaps a "better" solution was if premailer could expose the parsed lxml document in some form so that you can make those kinds of manipulations yourself.

Something like this:

import base64
import premailer

p = premailer.Premailer(html_string)
for img in p.cssselect('img.thumbnail'):
    fn = uri_to_local_file_path(img.attr('src'))
    b64 = base64.b64encode(open(fn, "rb").read())
    img.attr('src', f'data:image/png;base64,{b64}')
inlined_html = p.transform()

That way, all feature requests, like this issue, would be relatively taken care of.

Would you be interested in adding a feature like this @dov ?

[peterbe]

Due to organic slow growth the premailer API has evolved quite a bit. It used to be that you do:

p = premailer.Premailer(html_string)
print(p.transform())

But, if you have many different html_strings you can instead share 1 instance for all, like:

p = premailer.Premailer(**my_awesome_options)
for html_string in html_strings:
    print(p.transform(html_string))

So it's not a dead obvious place where to put the preprocessing. But it could be like this:

def my_mutating_pre_processor(instance):
    assert instance is p  # just for demonstration
    for img in instance.cssselect('img.thumbnail'):
        fn = uri_to_local_file_path(img.attr('src'))
        b64 = base64.b64encode(open(fn, "rb").read())
        img.attr('src', f'data:image/png;base64,{b64}')

p = premailer.Premailer(pre_processor=my_mutating_pre_processor, **my_awesome_options)
for html_string in html_strings:
    print(p.transform(html_string))

Let me know if you're interested in writing a patch. I can help with running tests and design.

[dov]

This is indeed my intention, and your suggestion for an API through the pre_processor function certainly makes sense. If I start working on a patch for this, I'll let you know.

[23tux]

Is there any news on this?

[peterbe]

Is there any news on this?

Not that I know. I still stand by my 2019 comment above I guess.