download image from temp bucket, split into 3 sizes, and reupload to app bucket

processImage.crud.ts

processImage(params) {
        console.log('imageProcess.processImage params: ', JSON.stringify(params));
        let key = params.key;
        let imageData;
        let bucketForUpload = 'app-' + serverConf.nodeEnv;
        if(key){
            var sizes = [50, 200, 800];
            const storage = new AWS.S3();
            var fn = function process(size) {
                return new Promise(function (resolve, reject) {
                    var width = size;
                    var height = size;
                    gm(imageData)
                        .setFormat('jpg')
                        .antialias(true)
                        .density(300)
                        .resize(width, height)
                        .stream(function (err, stdout, stderr) {
                            var data = {
                                Bucket: bucketForUpload,
                                Key: key.split('.')[0] + '_' + size + '.jpg',
                                Body: stdout,
                                ACL: 'public-read'
                            };
                            storage.upload(data, function(err, res) {
                                if(err){
                                    return reject(err);
                                }else{
                                    return resolve(res);
                                }
                            });
                        })
                })
            };
            return new Promise(function (resolve, reject) {
                storage.getObject({
                    Bucket: s3Config.bucket,
                    Key: key
                }, function(err, res){
                    if(err){return reject(err)}
                    resolve(res)
                })
            }).then((res: any) => {
                imageData = res.Body;
                var actions = sizes.map(fn);
                var results = Promise.all(actions);
                return new Promise(function(resolve, reject){
                    results.then(data => {
                        console.log('graphics magick date = '+ JSON.stringify(data));
                        resolve(data);
                    })
                })
            });
        }
}

@lukasasorensen Thank you for all this amazing information.

I thought if I was using Electron, I might be able to use the in built NodeJs server to run GM?

@charles1971 no problem mate. I'm not too familiar with Electron so I'm not too sure about it's ability to run something like GM, but I do know that it's just Chromium under the hood. I would search around google for something like "can I run server side nodejs on electron?"

@lukasasorensen I think the answer maybe yes:

https://stackoverflow.com/questions/35819200/nodejs-electron-confusion-about-client-server-code

But, it is still not 100% clear. I know that Electron can definitely access the client’s file system.

@charles1971 it seems that you are right, you can do this. https://stackoverflow.com/questions/45039779/how-to-install-imagemagick-inside-of-electron-app -- note: graphicsmagick is just a fork of imagemagick

@lukasasorensen Yes. But it looks pretty complicated:

https://github.com/joeherold/imagemagick-darwin-static

https://github.com/SamirL/graphicsmagick-static

Other:

https://stackoverflow.com/questions/51431188/how-do-you-install-and-bundle-graphicsmagick-in-an-electron-app

The problem is, I don’t know where I would write the code for the first two links above. The imagemagick-darwin-static doesn’t say where I should write this code. I am writing the app in TypeScript. I have dropped the Angular option, because it was preventing IPC calls from working properly.

I have an app.js which opens the Chromium and then I have a service inside src/app, which sets up the IPC messaging system.

I guess I should put the GraphicksMagick stuff in the app.js?