How to import local csv file into vue using vue-papa-parse?

Question

I have a vue project, where I want to select a local .csv and import the contents to a variable. I'm trying to do so via vue-papa-parse, which I've installed via npm. The following code (main.js, then a vue component) selects a file in browser but does nothing after that. The only hint in the console is an 'underfined' at ma-map.vue:33 (the console.log line).

The papa parse documentation mentions the config object should include a callback, which I haven't (and don't know how).

I'm not welded to the idea of papa parse but it seemed to have good reviews. Feedback appreciated.

The 'main.js' file:

import Vue from 'vue'
import VuePapaParse from 'vue-papa-parse'
import vSelect from 'vue-select'
import 'vue-select/dist/vue-select.css'
import VueRouter from 'vue-router'
import PouchDB from 'pouchdb-browser'
import App from './App.vue'
import {
  routes
} from './routes'

Vue.config.productionTip = false

Vue.component('v-select', vSelect)
Vue.use(VuePapaParse)
Vue.use(VueRouter)
  ...

<!-- Vue Component file -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js">
  < template >
    <
    div >
    <
    h3 > Import csv < /h3> <
  br / >
    <
    br / >
    <
    input type = "file"
  @change = "readFile" / > <!-- implicit event should return FileList -->
    <
    /div> < /
    template >

    <
    script >
    export default {
      data: function() {
        return {
          config: /* Papa Parse config object */ {
            delimiter: "", // auto-detect
            newline: "", // auto-detect
            quoteChar: '"',
            escapeChar: '"',
            header: true,
            dynamicTyping: true,
            preview: 0,
            encoding: "",
            delimitersToGuess: [',', '\t', '|', ';']
            // ?? callback function ??
          }
        }
      },
      methods: {
        readFile() {
          var fileToParse = event.target.files[0] /* returns first object in FileList */
          this.parsedFile = this.$papa.parse(fileToParse, this.config); /* from similar syntax in https://www.npmjs.com/package/vue-papa-parse#parse-local-files */
          console.log(this.parsedFile);
        }
      }
    };
</script>

Answer 1

I had the same problem, I used the above code but I can't dynamically update my vue data for example this.availability is undefined inside the complete config.

I solved it by creating another method and placed it to complete as a callback. Now, I am able to pass data to this.availability and update some UI.

<script>
export default {
data: function () {
    return {
        availability: {}
    }
},
methods: {
    onComplete(results, file){
      // Your logic here! functions or axios calls
      this.availability = results;
      console.log(this.availability);
    },
    readFile() {
        /* return first object in FileList */
        var file = event.target.files[0];
        this.$papa.parse(file, {
            header: true,
            complete: this.onComplete // your vue methods
        });
    }
  }
}
</script>