06-tweet-media-files.md

Tweet media files

This egghead.io video is a great resource for this section thanks to Hannah Davis for the awesome content!

This will be a request to get the NASA image of the day and tweet it.

For this we will need references to request and fs for working with the file system.

const Twit = require('twit')
const request = require('request')
const fs = require('fs')
const config = require('./config')

const bot = new Twit(config)

First up get the photo from the NASA api, for this we will need to create a parameter object inside our getPhoto function that will be passed to the node HTTP client request for the image:

function getPhoto() {
  const parameters = {
    url: 'https://api.nasa.gov/planetary/apod',
    qs: {
      api_key: process.env.NASA_KEY
    },
    encoding: 'binary'
  };
}

The parameters specify an api_key for this you can apply for an API key or you can use the DEMO_KEY this API key can be used for initially exploring APIs prior to signing up, but it has much lower rate limits, so you’re encouraged to signup for your own API key.

In the example you can see that I have configured my key with the rest of my .env variables.

CONSUMER_KEY=AmMSbxxxxxxxxxxNh4BcdMhxg
CONSUMER_SECRET=eQUfMrHbtlxxxxxxxxxxkFNNj1H107xxxxxxxxxx6CZH0fjymV
ACCESS_TOKEN=7xxxxx492-uEcacdl7HJxxxxxxxxxxecKpi90bFhdsGG2N7iII
ACCESS_TOKEN_SECRET=77vGPTt20xxxxxxxxxxxZAU8wxxxxxxxxxx0PhOo43cGO

NASA_KEY=DEMO_KEY

Now to use the request to get the image:

function getPhoto() {
  const parameters = {
    url: 'https://api.nasa.gov/planetary/apod',
    qs: {
      api_key: process.env.NASA_KEY
    },
    encoding: 'binary'
  };
  request.get(parameters, (err, respone, body) => {
    body = JSON.parse(body)
    saveFile(body, 'nasa.jpg')
  })
}

In the request we pass in our parameters and parse the body as JOSN so we can save it with the saveFile function which we'll go over now:

function saveFile(body, fileName) {
  const file = fs.createWriteStream(fileName);
  request(body).pipe(file).on('close', err => {
    if (err) {
      console.log(err)
    } else {
      console.log('Media saved!')
      console.log(body)
    }
  })
}

request(body).pipe(file).on('close'... is what saves the file from the file variable which has the name passed to it nasa.jpg from the getPhoto function.

Calling getPhoto() should now save the NASA image of the day to the root of your project.

Now we can share it on Twitter 😎

Two parts to this, first save the file.

function saveFile(body, fileName) {
  const file = fs.createWriteStream(fileName);
  request(body).pipe(file).on('close', err => {
    if (err) {
      console.log(err)
    } else {
      console.log('Media saved!')
      const descriptionText = body.title;
      uploadMedia(descriptionText, fileName)
    }
  })
}

Then uploadMedia to upload media to Twitter before we can post it, this had me stumped for a bit as I have my files in a src folder, if you have your bot files nested in folders then you will need to do the same if you are struggling with file does not exist errors:

Add a require to path then use join with the relevant relative file path.

const path = require('path')
//...
const filePath = path.join(__dirname, '../' + fileName)

Complete function here:

function uploadMedia(descriptionText, fileName) {
  console.log(`uploadMedia: file PATH ${fileName}`)
  bot.postMediaChunked({
    file_path: fileName
  }, (err, data, respone) => {
    if (err) {
      console.log(err)
    } else {
      console.log(data)
      const params = {
        status: descriptionText,
        media_ids: data.media_id_string
      }
      postStatus(params)
    }
  })
}

Then with the params we created in uploadMedia we can post with a straightforward .post('statuses/update'...

function postStatus(params) {
  bot.post('statuses/update', params, (err, data, respone) => {
    if (err) {
      console.log(err)
    } else {
      console.log('Status posted!')
    }
  })
}

Call the getPhoto() function top post to Twitter... super straight forward, right 😀 no, I know it wasn't. Here's the complete module:

const Twit = require('twit')
const request = require('request')
const fs = require('fs')
const config = require('./config')
const path = require('path')

const bot = new Twit(config)

function getPhoto() {
  const parameters = {
    url: 'https://api.nasa.gov/planetary/apod',
    qs: {
      api_key: process.env.NASA_KEY
    },
    encoding: 'binary'
  }
  request.get(parameters, (err, respone, body) => {
    body = JSON.parse(body)
    saveFile(body, 'nasa.jpg')
  })
}

function saveFile(body, fileName) {
  const file = fs.createWriteStream(fileName)
  request(body).pipe(file).on('close', err => {
    if (err) {
      console.log(err)
    } else {
      console.log('Media saved!')
      const descriptionText = body.title
      uploadMedia(descriptionText, fileName)
    }
  })
}

function uploadMedia(descriptionText, fileName) {
  const filePath = path.join(__dirname, `../${fileName}`)
  console.log(`file PATH ${filePath}`)
  bot.postMediaChunked({
    file_path: filePath
  }, (err, data, respone) => {
    if (err) {
      console.log(err)
    } else {
      console.log(data)
      const params = {
        status: descriptionText,
        media_ids: data.media_id_string
      }
      postStatus(params)
    }
  })
}

function postStatus(params) {
  bot.post('statuses/update', params, (err, data, respone) => {
    if (err) {
      console.log(err)
    } else {
      console.log('Status posted!')
    }
  })
}

getPhoto()

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