ndtech-svelte-components/src/RESTResources/RESTStore.js

Svelte components for building ndtech applications

import { writable } from 'svelte/store'
import * as api from './api'
import { Context } from '../Context/Context'

const cache = new Map();

function makeStore() {
  const store = writable(new Promise(() => { }))

  async function filter(arr, callback) {
    const fail = Symbol()
    return (await Promise.all(arr.map(async item => (await callback(item)) ? item : fail))).filter(i => i !== fail)
  }


  async function getCollection(resourceName) {

    if (cache.has(resourceName)) {
      store.set(Promise.resolve(cache.get(resourceName)))
    }

    try {

      const response = await api.get("http://localhost:5000/" + resourceName, {}, Context.user.token)
      const data = response.data
      cache.set(resourceName, data)
      store.set(Promise.resolve(data))
    }
    catch (err) {
      if(err == "Unauthorized"){
        store.set(Promise.reject("Unauthorized"));
      }
      else{
        store.set(Promise.reject(err));
      }
    }

    return store
  }

  async function deleteItem(resourceName, resourceId) {

    if (Context.user) {
      try {

        if (cache.has(resourceName)) {
          let resourceArray = cache.get(resourceName)

          let filteredArray = await filter(resourceArray, async (resource) => {
            var keepRecord = resource.id != resourceId;
            if (!keepRecord) {
              try {
                await api.del("http://localhost:5000/" + resourceName + "/" + resourceId, Context.user.token);
                console.log("keepRecord = " + keepRecord)
              }
              catch (e) {
                throw e;
              }
            }
            return keepRecord;
          });

          cache.set(resourceName, filteredArray)
          store.set(filteredArray)
        }

      }
      catch (err) {
        throw "Error deleting " + resourceId + " from " + resourceName + ": " + err.message
      }
    }
    else {
      throw "must login before deleting items"
    }

  }

  async function updateItem(resourceName, resourceId, resource) {

    if (Context.user) {
      try {

        if (cache.has(resourceName)) {
          let resourceArray = cache.get(resourceName)

          for (var i = 0; i < resourceArray.length; i++) {
            const resource = resourceArray[i];
            if (resource._id == resourceId) {
              resourceArray[i] = resource;
              break;
            }
          }

          try {

            await api.put("http://localhost:5000/" + resourceName + "/" + resourceId, resource, Context.user.token);
          }
          catch (e) {
            console.log("RESTStore.updateItem: error calling api.put: e = " + e);
            throw e;
          }

          // cache.set(resourceName, filteredArray)
          // store.set(filteredArray)
          console.log("logging resource = " + resource + " to get the linter off my back until I implement the real functionality");
          return resource;
        }

      }
      catch (err) {
        throw "Error deleting " + resourceId + " from " + resourceName + ": " + err.message
      }
    }
    else {
      throw "must login before updating items"
    }

  }

  async function createItem(resourceName, resource) {

    if (Context.user) {
      try {

        if (cache.has(resourceName)) {
          const resourceArray = cache.get(resourceName)
          const newResource = await api.post("http://localhost:5000/" + resourceName, resource, Context.user.token);
          resourceArray.push(newResource);

          cache.set(resourceName, resourceArray)
          store.set(resourceArray)

          return newResource;
        }

      }
      catch (err) {
        throw "Error deleting " + resource._id + " from " + resourceName + ": " + err.message
      }
    }
    else {
      throw "must login before updating items"
    }

  }

  async function getItem(resourceName, resourceId) {

    if (Context.user) {

      if (cache.has(resourceName)) {
        let resourceArray = cache.get(resourceName)

        return resourceArray.find(element => element._id == resourceId)
      }

    }
    else {
      throw "must login before getting items"
    }

  }


  return { getCollection, deleteItem, updateItem, createItem, getItem }
}

export const RESTStore = makeStore();