node 0.8.0 and toDataURL()

[lpinca]

toDataURL() method seems to fail with node 0.8.0
Tried with live-clock example and got this error:

TypeError: Cannot call method 'toString' of undefined
    at Canvas.toDataURL (/home/luigi/Desktop/node-canvas/lib/canvas.js:174:37)
    at Server.<anonymous> (/home/luigi/Desktop/node-canvas/examples/live-clock.js:111:29)
    at Server.EventEmitter.emit (events.js:91:17)
    at HTTPParser.parser.onIncoming (http.js:1785:12)
    at HTTPParser.parserOnHeadersComplete [as onHeadersComplete] (http.js:111:23)
    at Socket.socket.ondata (http.js:1682:22)
    at TCP.onread (net.js:404:27)

It seems that toBuffer() return undefined.

[wavded]

I'm getting something similar using 'nib' and gradient images: e.g. this fails:

background-image  : linear-gradient-image(200px, rgba(0,0,0,1), rgba(100,100,100,0.8))

with this error:

DEBUG: error:  500: TypeError: /home/wavded/Projects/arc/node_modules/nib/lib/nib/gradients.styl:148
   144|   start = start[1] or 'top'
   145|   grad = create-gradient-image(size, start)
   146|   stops = normalize-stops(stops)
   147|   add-color-stop(grad, stop[0], stop[1]) for stop in stops
 > 148|   'url(%s)' % gradient-data-uri(grad)
   149| 

Cannot call method 'toString' of undefined
    at ".humane" (/home/wavded/Projects/arc/assets/css/lib/humane.styl:12)
 stack=TypeError: /home/wavded/Projects/arc/node_modules/nib/lib/nib/gradients.styl:148
   144|   start = start[1] or 'top'
   145|   grad = create-gradient-image(size, start)
   146|   stops = normalize-stops(stops)
   147|   add-color-stop(grad, stop[0], stop[1]) for stop in stops
 > 148|   'url(%s)' % gradient-data-uri(grad)
   149| 

Cannot call method 'toString' of undefined
    at ".humane" (/home/wavded/Projects/arc/assets/css/lib/humane.styl:12)

    at Canvas.toDataURL (/home/wavded/Projects/arc/node_modules/canvas/lib/canvas.js:174:37)
    at Gradient.toDataURL (/home/wavded/Projects/arc/node_modules/nib/lib/nodes/gradient.js:158:17)
    at Evaluator.exports.dataURL (/home/wavded/Projects/arc/node_modules/nib/lib/nodes/gradient.js:61:32)
    at Evaluator.invokeBuiltin (/home/wavded/Projects/arc/node_modules/stylus/lib/visitor/evaluator.js:794:30)
    at Evaluator.visitCall (/home/wavded/Projects/arc/node_modules/stylus/lib/visitor/evaluator.js:341:16)
    at Evaluator.Visitor.visit (/home/wavded/Projects/arc/node_modules/stylus/lib/visitor/index.js:28:40)
    at Evaluator.visit (/home/wavded/Projects/arc/node_modules/stylus/lib/visitor/evaluator.js:75:18)
    at Evaluator.visitBinOp (/home/wavded/Projects/arc/node_modules/stylus/lib/visitor/evaluator.js:396:20)
    at Evaluator.Visitor.visit (/home/wavded/Projects/arc/node_modules/stylus/lib/visitor/index.js:28:40)
    at Evaluator.visit (/home/wavded/Projects/arc/node_modules/stylus/lib/visitor/evaluator.js:75:18), agent=Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/536.11 (KHTML, like Gecko) Chrome/20.0.1132.47 Safari/536.11, url=/css/layout.css?v=2.0.8, , v=2.0.8

[lpinca]

For the moment i got rid of the problem by removing this line https://github.com/LearnBoost/node-canvas/blob/master/src/closure.h#L46

[wavded]

That change fixed it for me, not sure if V8 will like it but :) Any thoughts @visionmedia ?

[ralphholzmann]

Bummer, that changed didn't fix it for me. Gonna have to comment out all the gradients in my app until this is fixed :(

[tj]

it's not the freeing of the data itself, it's the GC hint to v8. this must be prematurely dereferencing the buffer or something, if i have time ill check this out soon but we're pretty busy with some other stuff ATM

[ralphholzmann]

Understood @visionmedia, I just disabled nib for now, hope to use it again once this issue gets resolved. Thanks.

[RandomEtc]

I hit this problem too - in the meantime the async/callback versions of toBuffer and toDataURL seem to be working OK though.

[remoe]

i have it also with node-0.8.3 and canvas-0.12.1:

TypeError: Cannot call method 'toString' of undefined
    at Canvas.toDataURL (/canvas/lib/canvas.js:174:37)

and it works with async version of toDataURL.