Getting wrong file name for pdf or other type files except image file using input in Ionic(Android)?

I am using html input for selecting a file from file manager in my Ionic3/Angular application for Android/iOS. This below code is perfectly working in iOS and Browser. But, causing problem in Android for pdf files. I am using below code for this:

// in .html file

<input #fileUpload type="file" name="myfile"(change)="onFileChoose($event)"/>

// in .ts file

  onFileChoose($event): void {
    this.fileChooser.getFileInfo($event).then((result) => {
      this.fileName = result.fileName;
      this.fileData = this.sanitizeFileData(result.fileData);
      this.fileSize = result.fileSize;
      this.fileType = result.fileType;
    }, (error) => {
      this.helperProvider.createAlert('Alert', 'File is corrupted.');
    });
  }

 getFileInfo(event: Event): Promise<any> {

    let target = event && event.target;
    let files: Array<File> = target && target['files'];

    console.log(files[0].type);
    console.log(files[0].name);

    return new Promise((resolve, reject) => {
      if (files && files.length) {
        files = Array.from(files);
        let fileName = files[0].name;
        let fileSize = files[0].size;
        let fileType = files[0].type;
        let fileReader = new FileReader();

        fileReader.onload = () => resolve({
          fileData: fileReader.result,
          fileName: fileName,
          fileSize: fileSize,
          fileType: fileType
        });

        fileReader.onerror = error => reject(error);

        fileReader.onabort = error => reject(error);

        fileReader.readAsDataURL(files[0])
      }
    });
  }

I could perfectly select an image file from file manager in android and get the type, size and name of the file. But, when i select a pdf, suppose from downloads folder of file manager, i am getting the file type as empty and the file name as a different name than the original pdf file name. But, the size of the pdf file is correct.

Suppose, my pdf file name is “abc.pdf” but when i select the pdf file, i got the name as 5002 a random number and the type of the file as empty. I also saw that i am getting this behavior in all the files except the image files.

NOTE:

This is perfectly working in browser and iOS. But it is showing this weird behavior in android device.

Should i need any permission for reading pdf files using file manager in android?

Can anyone help me on this?

If you want to select file for native app use File Opener Plugin

Can you point me out what am i missing for pdf files while using input?

FileOpener plugin needs the path to the file. But, how will i know beforehand which file am i choosing and what file type of the file is?