Error converting markup with svgs

[JonasDoebertin]

Generally, creating an epub from my html markup works just fine and this library is a HUGE time saver. Thank you so much for creating and maintaining it!

There is only problem I'm facing right now though: Whenever my original HTML markup contains an <img> tag linking to a SVG file, adding it to a chapter fails (with EPub::EXTERNAL_REF_ADD enabled, to embed all image files into the epub file). Adding any other image format like PNGs and JPEGs works as expected and if I disable EPub::EXTERNAL_REF_ADD it works, too. I also tried adding other SVG files which still results in the error.

Here's the exact error message I'm facing:

PHP Warning:  imagecreatefromstring(): Data is not in a recognized format in /Users/path/to/project/vendor/grandt/phpepub/src/PHPePub/Core/EPub.php on line 615

This is the markup related to the SVG I'm trying to convert:

<figure>
    <img src="http://example.com/image.svg" alt="My svg image">
</figure>

Using the latest release with composer.

[Grandt]

Please have a look at 4.0.5-beta1
No guarantees, I only just had time to whip that one up.

[JonasDoebertin]

You're so fast! Thanks a lot for your efforts!

I'll have a look this evening.

[JonasDoebertin]

Seems to work beautifully. Thank you so much!

[Grandt]

Can I get you to test one more thing while you are at it?
Try to add a very large SVG (2000x2000 or more) The new code should reduce its size to the confines of the $maxImageWidth/$maxImageHeight settings in EPub.

[JonasDoebertin]

Hmmm, that doesn't seem to work. Tried adding a 4000x4000 pixels svg file. The svg file included within the .epub is exactly the same as the original file (except that some attributes on the main <svg> element are reordered).

Original svg:

<?xml version="1.0" standalone="no"?><!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"><svg width="100%" height="100%" viewBox="0 0 4000 4000" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve" style="fill-rule:evenodd;clip-rule:evenodd;stroke-linejoin:round;stroke-miterlimit:1.41421;"><g id="Ebene1"><rect x="411.445" y="269.874" width="1021.12" height="1153.57" style="fill:#50df50;"/><ellipse cx="3061.76" cy="1551.06" rx="619.986" ry="1117.49" style="fill:#d2e7e7;"/><path d="M2938.12,1540.04c0,-284.276 -230.796,-515.071 -515.071,-515.071l-1030.14,0c-284.275,0 -515.071,230.795 -515.071,515.071l0,1106.84c0,284.276 230.796,515.071 515.071,515.071l1030.14,0c284.275,0 515.071,-230.795 515.071,-515.071l0,-1106.84Z" style="fill:#ec5656;"/></g></svg>

Svg in epub file:

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="100%" height="100%" viewBox="0 0 4000 4000" version="1.1" xml:space="preserve" style="fill-rule:evenodd;clip-rule:evenodd;stroke-linejoin:round;stroke-miterlimit:1.41421;"><g id="Ebene1"><rect x="411.445" y="269.874" width="1021.12" height="1153.57" style="fill:#50df50;"/><ellipse cx="3061.76" cy="1551.06" rx="619.986" ry="1117.49" style="fill:#d2e7e7;"/><path d="M2938.12,1540.04c0,-284.276 -230.796,-515.071 -515.071,-515.071l-1030.14,0c-284.275,0 -515.071,230.795 -515.071,515.071l0,1106.84c0,284.276 230.796,515.071 515.071,515.071l1030.14,0c284.275,0 515.071,-230.795 515.071,-515.071l0,-1106.84Z" style="fill:#ec5656;"/></g></svg>

[Grandt]

I think I'll change that and leave the SVG's be. Setting their size changes nothing anyway, unlike the bitmap formats where that'll reduce the size of the files as well.

[JonasDoebertin]

Seems like your latest commit broke things.

I guess this line (57f3c11#diff-738d6dc186ddd5f8e5366f4bef5652b0R634) shouldn't be commented out, right?

[Grandt]

Agreed, the width and height aren't being set. I'm looking at extracting the SVG metadata now..

[JonasDoebertin]

Nah, I meant the $image = $xml->asXML(); line which was commented out too by accident, i guess.

[JonasDoebertin]

I don't think extracting SVG meta data is necessary. It works fine, even with huge SVGs, right now.

[Grandt]

The reason I commented that $image line out was that it should have been irrelevant. $image was already set.

I have committed another one, as I had practically already finished the rescale part. All I'm doing now is reading the hight/width from the viewbox, and place the rescaled size in the width/height attributes.
I builds a valid epub here, though I have to go get a good SVG to test on.
If this build fails on your end, I'll comment out the rescaling segment until I crack it right, or feel confident that it'll work and readers will rescale it themselves.

[JonasDoebertin]

Seems to work fine with your latest commit. All SVGs get the correct width/height attributes applied and the ePub displays fine for me.

[Grandt]

Thank you for helping me test this. :)

[JonasDoebertin]

Thank you for maintaining this lib so actively!

[Grandt]

Feel free to let me know if you have any other issues.