Anyone who did parse xlsx data from real device?

Ionic Framework ionic-v3
1

I did parse png file from my device and display on ionic app

but I can’t do it to xlsx file.
below image is the log that I get from code “this.file.checkDir…”
16

below is how I did parse image file…
I used http get request, papaparse…but all failed…
how can I parse xlsx data from device?

this.file.checkDir(this.file.externalRootDirectory, 'rrr').then(e => {console.log('Directory exists')
      this.file.listDir(this.file.externalRootDirectory,"rrr").then((e)=>{
        console.log(e);
        console.log(e.length); //2
      
      
        this.file.readAsDataURL(this.file.externalRootDirectory+"/rrr", "test.png").then(res=> {

          this.ee=res; //image is okay
        
          console.log("res");
          console.log(res);
        }).catch((e)=>{
          console.log("eerr");
          console.log(e);
        })