remix-project/src/publishToStorage.js

const yo = require('yo-yo')
const publishOnSwarm = require('./lib/publishOnSwarm')
const publishOnIpfs = require('./lib/publishOnIpfs')
const modalDialogCustom = require('./app/ui/modal-dialog-custom')

export default function publish (storage, fileProvider, fileManager, contract) {
  if (contract) {
    if (contract.metadata === undefined || contract.metadata.length === 0) {
      modalDialogCustom.alert('This contract may be abstract, may not implement an abstract parent\'s methods completely or not invoke an inherited contract\'s constructor correctly.')
    } else {
      if (storage === 'swarm') {
        publishOnSwarm(contract, fileManager, function (err, uploaded) {
          if (err) {
            try {
              err = JSON.stringify(err)
            } catch (e) {}
            console.log(`Failed to publish metadata file to swarm, please check the Swarm gateways is available ( swarm-gateways.net ) ${err}`)
          } else {
            var result = yo`<div>${uploaded.map((value) => {
              return yo`<div><b>${value.filename}</b> : <pre>${value.output.url}</pre></div>`
            })}</div>`
            modalDialogCustom.alert(`Published ${contract.name}'s Metadata`, yo`<span>Metadata of "${contract.name.toLowerCase()}" was published successfully.<br> <pre>${result}</pre> </span>`)
          }
        }, (item) => { // triggered each time there's a new verified publish (means hash correspond)
          fileProvider.addExternal('swarm/' + item.hash, item.content)
        })
      } else {
        publishOnIpfs(contract, fileManager, function (err, uploaded) {
          if (err) {
            try {
              err = JSON.stringify(err)
            } catch (e) {}
            modalDialogCustom.alert(yo`<span>Failed to publish metadata file to ${storage}, please check the ${storage} gateways is available.<br />
            ${err}</span>`)
          } else {
            var result = yo`<div>${uploaded.map((value) => {
              return yo`<div><b>${value.filename}</b> : <pre>${value.output.url}</pre></div>`
            })}</div>`
            modalDialogCustom.alert(`Published ${contract.name}'s Metadata`, yo`<span>Metadata of "${contract.name.toLowerCase()}" was published successfully.<br> <pre>${result}</pre> </span>`)
          }
        }, (item) => { // triggered each time there's a new verified publish (means hash correspond)
          fileProvider.addExternal('ipfs/' + item.hash, item.content)
        })
      }
    }
  }
}