CODEWITHSUNDEEP
node.jsstreamimagemagick
Issac Howard
Issac Howard

Reputation: 329

ImageMagick Convert Pipe not working in Node

My main goal is to convert an SVG tag to PNG using Node.js and ImageMagick. I am also caching data to a Transform stream that writes to a file. I have the SVG tag ready, and when I either console.log or process.stdout.write anything in the _transform function, nothing is outputted on my terminal.

let streamer = new Transform()
streamer._transform = function(data, enc, cb) {
        stdout.write('Does this even run?') // or console.log
        stdout.write(data)
        fileWriter.write(data)
        this.push(data)
        cb()
      }
let svgToPng = cp.spawn('convert', ["svg:", "png:-"])
svgToPng.stdout.pipe(streamer).pipe(res)

let svgStr = `<svg>` + svg.node().innerHTML + `</svg>`
svgToPng.stdin.write(svgStr, (err) => {
    console.log(err) // null
}) // svgStr is valid SVG
svgToPng.stdin.end()

Now spawn does not make a new node process but makes a POSIX process I believe and couldn't really figure out how to debug the a POSIX process from VSCode or a Node process in general.

I know that the correct way to convert an SVG to PNG via ImageMagick solely is

echo SVG_INNERHTML | convert svg:- png:-

I have a feeling that spawn does not automatically do echo which is kind of vital and that it does

SVG_INNERHTML | convert svg:- png:-

Again these are just my predictions, all I want to do is convert an SVG to PNG via imageMagick.

Any explanation (or even just how to debug this) would be great.

Upvotes: 1

Views: 16

Answers (0)

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