Examples for http://blog.diovani.com/technology/2017/02/11/flattening-javascript-modules.html

.env.example

GCLOUD_PROJECT_ID=
GCLOUD_KEY_FILENAME=

QUANTITY=3
RESOLUTION=1024/576

00-example1.js

request.get('http://example.com', (err, res, body) => {
    if (!error && res.statusCode == 200) {
        const content = body.replace(/(<([^>]+)>)/ig, '')

        fs.writeFile('contents.txt', content, (err) => {
            console.log('contents are saved.')
        })
    }
})

00-example2.js

request.get('http://example.com')
.then(stripTags)
.then(writeToFile)
.then(console.log)
.catch(console.error)

01-original.js

'use strict'

require('dotenv').config({ silent: true })

const Exec = require('child_process').exec
const Fs = require('fs')
const Request = require('request')
const Vision = require('@google-cloud/vision')

const visionClient = Vision({
    projectId: process.env.GCLOUD_PROJECT_ID,
    keyFilename: process.env.GCLOUD_KEY_FILENAME
})

const imageUrl = (id) => `https://unsplash.it/${process.env.RESOLUTION}?image=${id}`

const imageFilename = (id) => `img-${id}.jpg`

const sample = (collection, quantity = 1) => {
    const samples = []
    const max = quantity - 1

    for (let i = 0; i <= max; i++) {
        const index = Math.ceil(Math.random() * collection.length -1)
        samples.push(collection[index])
    }

    return samples
}

const applyLabels = (img, cb) => {
    const labels = img.labels.slice(0, 3)
    const command = `
        convert ${imageFilename(img.id)} -pointsize 30 -font 'DejaVu-Sans-Bold' -strokewidth 2 \
        -draw "gravity north stroke black fill white text 0,20 '${labels.join(' | ')}' " \
        -draw "gravity south stroke black fill white text 0,20 'by ${img.author}' " \
        ${imageFilename(img.id)}
    `

    Exec(command, cb)
}

// request full image list from unsplash.it
Request.get('https://unsplash.it/list', (err, res, body) => {
    if (err) {
        return console.error(err)
    }

    // get some samples
    const json = JSON.parse(body)
    const images = sample(json, process.env.QUANTITY)

    // process each image...
    images.forEach((img) => {
        // download for local filesystem
        Request.get(imageUrl(img.id))
        .pipe(Fs.createWriteStream(imageFilename(img.id)))
        .on('close', () => {

            // send image to Google Cloud Vision to get image labels
            visionClient.detectLabels(imageUrl(img.id), (err, labels, apiRes) => {
                if (err) {
                    return console.error(err)
                }
                const data = Object.assign(img, { labels })

                // add text to images with image magic
                applyLabels(data, (err) => {
                    if (err) {
                        return console.error(err)
                    }
                })
            })
        })
    })
})

02-promises-partial.js

const Promise = require('bluebird')
const Exec = Promise.promisify(require('child_process').exec)

//...

const applyLabels = (data) => {
    //...
    return Exec(command)
}

//...

// request full image list from unsplash.it
Request.get('https://unsplash.it/list')
.then((body) => {
    // get some samples
    const json = JSON.parse(body)
    const images = sample(json, process.env.QUANTITY)

    // process each image...
    images.forEach((img) => {
        // download for local filesystem
        new Promise((resolve, reject) => {
            Request.get(imageUrl(img.id))
            .pipe(Fs.createWriteStream(imageFilename(img.id)))
            .on('close', resolve)
            .on('error', reject)
        })
        //send image to Google Cloud Vision to get image labels
        .then(() => visionClient.detectLabels(imageUrl(img.id)))
        .then(([labels]) => {
            const data = Object.assign(img, { labels })

            // add text to images with image magic
            return applyLabels(data)
        })
        .catch(console.error)
    })
})
.catch(console.error)

02-promises.js

'use strict'

require('dotenv').config({ silent: true })

const Fs = require('fs')
const Promise = require('bluebird')
const Request = require('request-promise')
const Vision = require('@google-cloud/vision')
const Exec = Promise.promisify(require('child_process').exec)

const visionClient = Vision({
    projectId: process.env.GCLOUD_PROJECT_ID,
    keyFilename: process.env.GCLOUD_KEY_FILENAME
})

const imageUrl = (id) => `https://unsplash.it/${process.env.RESOLUTION}?image=${id}`

const imageFilename = (id) => `img-${id}.jpg`

const sample = (collection, quantity = 1) => {
    const samples = []
    const max = quantity - 1

    for (let i = 0; i <= max; i++) {
        const index = Math.ceil(Math.random() * collection.length -1)
        samples.push(collection[index])
    }

    return samples
}

const applyLabels = (img) => {
    const labels = img.labels.slice(0, 3)
    const command = `
        convert ${imageFilename(img.id)} -pointsize 30 -font 'DejaVu-Sans-Bold' -strokewidth 2 \
        -draw "gravity north stroke black fill white text 0,20 '${labels.join(' | ')}' " \
        -draw "gravity south stroke black fill white text 0,20 'by ${img.author}' " \
        ${imageFilename(img.id)}
    `

    return Exec(command)
}

// request full image list from unsplash.it
Request.get('https://unsplash.it/list')
.then((body) => {
    // get some samples
    const json = JSON.parse(body)
    const images = sample(json, process.env.QUANTITY)

    // process each image...
    images.forEach((img) => {
        // download for local filesystem
        new Promise((resolve, reject) => {
            Request.get(imageUrl(img.id))
            .pipe(Fs.createWriteStream(imageFilename(img.id)))
            .on('close', resolve)
            .on('error', reject)
        })
        //send image to Google Cloud Vision to get image labels
        .then(() => visionClient.detectLabels(imageUrl(img.id)))
        .then(([labels]) => {
            const data = Object.assign(img, { labels })

            // add text to images with image magic
            return applyLabels(data)
        })
        .catch(console.error)
    })
})
.catch(console.error)

03-map-partial.js

// request full image list from unsplash.it
Request.get('https://unsplash.it/list')
.then((body) => {
    // get some samples
    const json = JSON.parse(body)
    const images = sample(json, process.env.QUANTITY)

    // process each image...
    return images.map((img) => {
        // download for local filesystem
        return new Promise((resolve, reject) => {
            Request.get(imageUrl(img.id))
            .pipe(Fs.createWriteStream(imageFilename(img.id)))
            .on('close', resolve)
            .on('error', reject)
        })
        .then(() => img)
    })
})
.then((promises) => Promise.all(promises))
//send images to Google Cloud Vision to get image labels
.then((images) => {
    return images.map((img) => {
        return visionClient.detectLabels(imageUrl(img.id))
        .then(([labels]) => Object.assign(img, { labels }))
    })
})
.then((promises) => Promise.all(promises))
//add text to images with image magic
.then((images) => {
    return images.map((img) => applyLabels(img))
})
.catch(console.error)

03-map.js

'use strict'

require('dotenv').config({ silent: true })

const Fs = require('fs')
const Promise = require('bluebird')
const Request = require('request-promise')
const Vision = require('@google-cloud/vision')
const Exec = Promise.promisify(require('child_process').exec)

const visionClient = Vision({
    projectId: process.env.GCLOUD_PROJECT_ID,
    keyFilename: process.env.GCLOUD_KEY_FILENAME
})

const imageUrl = (id) => `https://unsplash.it/${process.env.RESOLUTION}?image=${id}`

const imageFilename = (id) => `img-${id}.jpg`

const sample = (collection, quantity = 1) => {
    const samples = []
    const max = quantity - 1

    for (let i = 0; i <= max; i++) {
        const index = Math.ceil(Math.random() * collection.length -1)
        samples.push(collection[index])
    }

    return samples
}

const applyLabels = (img) => {
    const labels = img.labels.slice(0, 3)
    const command = `
        convert ${imageFilename(img.id)} -pointsize 30 -font 'DejaVu-Sans-Bold' -strokewidth 2 \
        -draw "gravity north stroke black fill white text 0,20 '${labels.join(' | ')}' " \
        -draw "gravity south stroke black fill white text 0,20 'by ${img.author}' " \
        ${imageFilename(img.id)}
    `

    return Exec(command)
}

// request full image list from unsplash.it
Request.get('https://unsplash.it/list')
.then((body) => {
    // get some samples
    const json = JSON.parse(body)
    const images = sample(json, process.env.QUANTITY)

    // process each image...
    return images.map((img) => {
        // download for local filesystem
        return new Promise((resolve, reject) => {
            Request.get(imageUrl(img.id))
            .pipe(Fs.createWriteStream(imageFilename(img.id)))
            .on('close', resolve)
            .on('error', reject)
        })
        .then(() => img)
    })
})
.then((promises) => Promise.all(promises))
//send images to Google Cloud Vision to get image labels
.then((images) => {
    return images.map((img) => {
        return visionClient.detectLabels(imageUrl(img.id))
        .then(([labels]) => Object.assign(img, { labels }))
    })
})
.then((promises) => Promise.all(promises))
//add text to images with image magic
.then((images) => {
    return images.map((img) => applyLabels(img))
})
.catch(console.error)

04-extract-partial.js

//...

const requestImageList = (url) => Request.get(url)

//...

requestImageList('https://unsplash.it/list')
.then((body) => JSON.parse(body))
.then((json) => sample(json, process.env.QUANTITY))
.then((images) => images.map(downloadImage))
.then((promises) => Promise.all(promises))
.then((images) => images.map(detectLabels))
.then((promises) => Promise.all(promises))
.then((images) => images.map(applyLabels))
.catch(console.error)

04-extract.js

'use strict'

require('dotenv').config({ silent: true })

const Fs = require('fs')
const Promise = require('bluebird')
const Request = require('request-promise')
const Vision = require('@google-cloud/vision')
const Exec = Promise.promisify(require('child_process').exec)

const visionClient = Vision({
    projectId: process.env.GCLOUD_PROJECT_ID,
    keyFilename: process.env.GCLOUD_KEY_FILENAME
})

const imageUrl = (id) => `https://unsplash.it/${process.env.RESOLUTION}?image=${id}`

const imageFilename = (id) => `img-${id}.jpg`

const sample = (collection, quantity = 1) => {
    const samples = []
    const max = quantity - 1

    for (let i = 0; i <= max; i++) {
        const index = Math.ceil(Math.random() * collection.length -1)
        samples.push(collection[index])
    }

    return samples
}

const requestImageList = (url) => Request.get(url)

const downloadImage = (img) => {
    return new Promise((resolve, reject) => {
        Request.get(imageUrl(img.id))
        .pipe(Fs.createWriteStream(imageFilename(img.id)))
        .on('close', resolve)
        .on('error', reject)
    })
    .then(() => img)
}

const detectLabels = (img) => {
    return visionClient.detectLabels(imageUrl(img.id))
    .then(([labels]) => Object.assign(img, { labels }))
}

const applyLabels = (img) => {
    const labels = img.labels.slice(0, 3)
    const command = `
        convert ${imageFilename(img.id)} -pointsize 30 -font 'DejaVu-Sans-Bold' -strokewidth 2 \
        -draw "gravity north stroke black fill white text 0,20 '${labels.join(' | ')}' " \
        -draw "gravity south stroke black fill white text 0,20 'by ${img.author}' " \
        ${imageFilename(img.id)}
    `

    return Exec(command)
}

requestImageList('https://unsplash.it/list')
.then((body) => JSON.parse(body))
.then((json) => sample(json, process.env.QUANTITY))
.then((images) => images.map(downloadImage))
.then((promises) => Promise.all(promises))
.then((images) => images.map(detectLabels))
.then((promises) => Promise.all(promises))
.then((images) => images.map(applyLabels))
.catch(console.error)

05-curry-partial.js

//...

const R = require('ramda')

//...

const sample = R.curry((quantity, collection) => {
    //...
})

//...

requestImageList('https://unsplash.it/list')
.then(JSON.parse)
.then(sample(process.env.QUANTITY))
.then(R.map(downloadImage))
.then(Promise.all)
.then(R.map(detectLabels))
.then(Promise.all)
.then(R.map(applyLabels))
.catch(console.error)

05-curry.js

'use strict'

require('dotenv').config({ silent: true })

const Fs = require('fs')
const Promise = require('bluebird')
const R = require('ramda')
const Request = require('request-promise')
const Vision = require('@google-cloud/vision')
const Exec = Promise.promisify(require('child_process').exec)

const visionClient = Vision({
    projectId: process.env.GCLOUD_PROJECT_ID,
    keyFilename: process.env.GCLOUD_KEY_FILENAME
})

const imageUrl = (id) => `https://unsplash.it/${process.env.RESOLUTION}?image=${id}`

const imageFilename = (id) => `img-${id}.jpg`

const sample = R.curry((quantity, collection) => {
    const samples = []
    const max = quantity - 1

    for (let i = 0; i <= max; i++) {
        const index = Math.ceil(Math.random() * collection.length -1)
        samples.push(collection[index])
    }

    return samples
})

const requestImageList = (url) => Request.get(url)

const downloadImage = (img) => {
    return new Promise((resolve, reject) => {
        Request.get(imageUrl(img.id))
        .pipe(Fs.createWriteStream(imageFilename(img.id)))
        .on('close', resolve)
        .on('error', reject)
    })
    .then(() => img)
}

const detectLabels = (img) => {
    return visionClient.detectLabels(imageUrl(img.id))
    .then(([labels]) => Object.assign(img, { labels }))
}

const applyLabels = (img) => {
    const labels = img.labels.slice(0, 3)
    const command = `
        convert ${imageFilename(img.id)} -pointsize 30 -font 'DejaVu-Sans-Bold' -strokewidth 2 \
        -draw "gravity north stroke black fill white text 0,20 '${labels.join(' | ')}' " \
        -draw "gravity south stroke black fill white text 0,20 'by ${img.author}' " \
        ${imageFilename(img.id)}
    `

    return Exec(command)
}

requestImageList('https://unsplash.it/list')
.then(JSON.parse)
.then(sample(process.env.QUANTITY))
.then(R.map(downloadImage))
.then(Promise.all)
.then(R.map(detectLabels))
.then(Promise.all)
.then(R.map(applyLabels))
.catch(console.error)