Simple example of WebTask Storage

README.md

This example demostrate the usage of WebTask Storage with multiple models and how to save / filter / find them.

$ curl https://__host__.run.webtask.io/example\?action\=delete_all
{}

$ curl https://__host__.run.webtask.io/example\?action\=save_model \
  -H "Content-Type: application/json" \
  --data '{"modelName": "planets", "properties": {"name": "Earth"}}'
{}

$ curl https://__host__.run.webtask.io/example\?action\=save_model \
  -H "Content-Type: application/json" \
  --data '{"modelName": "planets", "properties": {"name": "Mars"}}' 
{}

$ curl https://__host__.run.webtask.io/example\?action\=filter_model \
  -H "Content-Type: application/json"\
  --data '{"modelName": "planets", "properties": {"name": "Mars"}}'
[{"name":"Mars"}]

$ curl https://__host__.run.webtask.io/example\?action\=find_model \
  -H "Content-Type: application/json" \
  --data '{"modelName": "planets", "properties": {"name": "Mars"}}'
{"name":"Mars"}

webtask-storage.js

const Bluebird = require('bluebird@3.5.0')
const lodash = require('lodash@4.8.2')

/**
 * storage is an Object with properties as Array models:
 * storage: {
 *   modelA: [{id: 1, name: 'example'}],
 *   modelB: [{id: 1, color: 'red'}]  
 * }
 */
const getStorage = (ctx) => Bluebird.fromCallback(cb => {
  ctx.storage.get(cb)
})

const getObjectStorage = (ctx) => getStorage(ctx)
  .then(storage => (typeof storage === 'object') ? storage : {})

const setStorage = (ctx, data, force) => Bluebird.fromCallback(cb => {
  ctx.storage.set(data, {force}, cb)
})

const getModels = (ctx, modelName) => Bluebird.try(() => {
  if (!modelName) {
    throw new Error('modelName not provided')
  }
  return getObjectStorage(ctx).then(storage => {
    if (!Array.isArray(storage[modelName])) {
      storage[modelName] = []
    }
    return storage[modelName]
  })
})
  
const filterModel = (ctx, modelName, props) =>
  getModels(ctx, modelName).then(models => lodash.filter(models, props))
  
const findModel = (ctx, modelName, props) =>
  getModels(ctx, modelName).then(models => lodash.find(models, props))

const saveModel = (ctx, modelName, props) => Bluebird.try(() => {
  if (!modelName) {
    throw new Error('modelName not provided')
  }
  return getObjectStorage(ctx).then(storage => {
    if (!storage[modelName]) {
      storage[modelName] = []
    }
    storage[modelName].push(props)
    return setStorage(ctx, storage)
  })
})

const main = (ctx) => Bluebird.try(() => {
  const action = ctx.query.action
  
  console.log(`Action: ${action}`)
  console.log('Body: %j', ctx.body)
  
  switch (action) {
    case 'get_storage': {
      return getStorage(ctx)
    }
    case 'get_models': {
      return getModels(ctx, ctx.body.modelName)
    }
    case 'save_model': {
      return saveModel(ctx, ctx.body.modelName, ctx.body.properties)
    }
    case 'filter_model': {
      return filterModel(ctx, ctx.body.modelName, ctx.body.properties)
    }
    case 'find_model': {
      return findModel(ctx, ctx.body.modelName, ctx.body.properties)
    }
    case 'delete_all': {
      return setStorage(ctx, {}, 1)
    }
    default: {
      throw new Error('Action not allowed')
    }
  }
})

module.exports = (ctx, cb) => main(ctx)
  .then(resp => {
    console.log('Response will be:', resp)
    cb(null, resp) 
  })
  .catch(err => {
    console.error('Response error')
    console.error(err)
    cb(err.message, null) 
  })