The problem here is that I can't fetch the entire row from a single read... I have to make multiple reads. I am unable to implement a table_row object which can hold all the values of a row.
As an alternative I have tried to make a array of row data but I am unable to do so because "ondatachanged" is a async function; hence i am getting "null".
Please note if I use multiple objects to store the data of a single row then at last how can I map that all and make a final table.
I hereby attatch my lenghty code below
public int generate_pdf() throws IOException{
fetch_cls_details();
String pdf_path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS).toString();
File file = new File(pdf_path,"attadence_AttandX.pdf");
OutputStream outputStream = new FileOutputStream(file);
PdfWriter writer = new PdfWriter(file);
PdfDocument pdfDocument = new PdfDocument(writer);
Document document = new Document(pdfDocument);
document.setMargins(0,0,0,0);
Drawable bg_pdf = getDrawable(R.drawable.bg);
Bitmap bg_pdf_bitmap =((BitmapDrawable)bg_pdf ).getBitmap();
ByteArrayOutputStream stream1 = new ByteArrayOutputStream();
bg_pdf_bitmap.compress(Bitmap.CompressFormat.JPEG,100,stream1);
byte[] bg_pdf_bitmap_data = stream1.toByteArray();
ImageData imageData1 = ImageDataFactory.create(bg_pdf_bitmap_data);
Image bg_pdf_img = new Image(imageData1);
Drawable header_pdf = getDrawable(R.drawable.headerpdf);
Bitmap header_bitmap =((BitmapDrawable)header_pdf ).getBitmap();
ByteArrayOutputStream stream2 = new ByteArrayOutputStream();
header_bitmap.compress(Bitmap.CompressFormat.JPEG,100,stream2);
byte[] header_pdf_bitmap_data = stream2.toByteArray();
ImageData imageData2 = ImageDataFactory.create(header_pdf_bitmap_data);
Image header_pdf_img = new Image(imageData2);
// class details table
// we have to make 3 functions 1 for class details from header. 1 for attadence data 1 for calculation (not sure
List l1 = new List();
l1.add(cls_name_str);
l1.add(sub_name_str);
l1.add(sub_code_str);
Table header_table = new Table(2);
header_table.setMarginTop(30F);
header_table.setFont(PdfFontFactory.createFont(StandardFonts.HELVETICA));
header_table.addCell(new Cell().add(l1)
.setPaddingLeft(30F)
.setTextAlignment(TextAlignment.LEFT)
.setBorder(Border.NO_BORDER)
.setFontSize(18)
);
header_table.addCell(new Cell().add(new Paragraph(created_by_str))
.setBorder(Border.NO_BORDER)
.setPaddingLeft(270F)
.setFontSize(30)
);
float[] col_width = {1,3,2,1,1,1};
String[] body_header_val = {"#","Name","Phone","Present No","Total","percentage"};
Table body_table = new Table(col_width);
body_table.setWidth(UnitValue.createPercentValue(100));
body_table.setFont(PdfFontFactory.createFont(StandardFonts.HELVETICA));
for(int i = 0; i <= body_header_val.length-1; i++){
body_table.addHeaderCell(new Cell().add(new Paragraph(body_header_val[i]))
.setBorder(Border.NO_BORDER)
.setPadding(5)
.setBackgroundColor(new DeviceRgb(118, 179, 236))
.setFontColor(ColorConstants.WHITE)
.setTextAlignment(TextAlignment.CENTER)
);
Log.d("TABLE_VALUE", body_header_val[i]);
}
table_helper table_helper_obj = new table_helper();
DatabaseReference root_ref,this_cls_data_ref,this_cls_header_ref;
root_ref = FirebaseDatabase.getInstance().getReference();
this_cls_header_ref = root_ref.child("classroom_header").child(room_id);
this_cls_data_ref = root_ref.child(room_id).child("attedance_data");
// lets map data into array first then we will loop dis array to print in table with customizations
ArrayList<String[]> full_table_data_array = new ArrayList<>();
String[] table_row = new String[6];
table_row[4] = String.valueOf(total_cls_taken);
this_cls_data_ref.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot snapshot) {
if(snapshot.exists()){
Log.d(TAG+"_PDF", "snapshot "+snapshot.toString());
long no_of_child = snapshot.getChildrenCount();
Log.d(TAG+"_PDF", "NO of child = "+no_of_child);
DatabaseReference user_profile_ref;
user_profile_ref = root_ref.child("userprofile");
//main pt
for (DataSnapshot snapshot1 : snapshot.getChildren())
{
String UID;
int serial_no = 1;
body_table.addCell(new Cell().add(new Paragraph(String.valueOf(serial_no)))
.setBorder(Border.NO_BORDER)
.setPadding(5)
.setBackgroundColor(ColorConstants.WHITE)
.setFontColor(ColorConstants.BLACK)
.setTextAlignment(TextAlignment.CENTER)
);
table_helper_obj.setSerial_no(String.valueOf(serial_no));
Log.d(TAG3, "ROW"+serial_no +"#"+serial_no);
UID = snapshot1.getKey();
int finalSerial_no = serial_no;
int finalSerial_no1 = serial_no;
user_profile_ref.child(UID).addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot snapshot) {
String u_name,u_phn;
if (snapshot.exists()){
u_name = (String) snapshot.child("name").getValue();
u_phn = (String) snapshot.child("phone").getValue();
Log.d(TAG2, "USERNAME "+u_name+"\tPHONE "+u_phn+"of "+UID);
body_table.addCell(new Cell().add(new Paragraph(String.valueOf(u_name)))
.setBorder(Border.NO_BORDER)
.setBackgroundColor(ColorConstants.WHITE)
.setFontColor(ColorConstants.BLACK)
.setTextAlignment(TextAlignment.CENTER)
);
body_table.addCell(new Cell().add(new Paragraph(String.valueOf(u_phn)))
.setBorder(Border.NO_BORDER)
.setBackgroundColor(ColorConstants.WHITE)
.setFontColor(ColorConstants.BLACK)
.setTextAlignment(TextAlignment.CENTER)
);
table_helper_obj.setName(u_name);
table_helper_obj.setPhn(u_phn);
Log.d(TAG3, "ROW"+ finalSerial_no +"Name"+ u_name);
Log.d(TAG3, "ROW"+ finalSerial_no +"PHONE"+ u_phn);
}else{
Toast.makeText(getApplicationContext(), "USER_DETAILS FOR PDF NOT FOUND", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
}
});
Query q1 = this_cls_data_ref.child(UID).orderByValue().equalTo("PRESENT");
int finalSerial_no2 = serial_no;
q1.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot snapshot) {
int total_present_no;
total_present_no = (int)snapshot.getChildrenCount();
body_table.addCell(new Cell().add(new Paragraph(String.valueOf(total_present_no))).setBorder(Border.NO_BORDER).setBackgroundColor(ColorConstants.WHITE).setFontColor(ColorConstants.BLACK).setTextAlignment(TextAlignment.CENTER));
table_helper_obj.setTotal_present(String.valueOf(total_present_no));
Log.d(TAG3, "ROW"+ finalSerial_no2 +"TOTAL PRESENT"+String.valueOf(total_present_no));
float percentage = ((float) total_present_no / Float.parseFloat(total_cls_taken)) * 100;
body_table.addCell(new Cell().add(new Paragraph(String.valueOf(percentage))).setBorder(Border.NO_BORDER).setBackgroundColor(ColorConstants.WHITE).setFontColor(ColorConstants.BLACK).setTextAlignment(TextAlignment.CENTER));
table_helper_obj.setPercentage(String.valueOf(percentage));
Log.d(TAG3, "ROW"+ finalSerial_no2 +"PERCENTAGE"+percentage);
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
}
});
serial_no++;
}
}
else
{
Toast.makeText(ClassroomDashboard.this, "attadance data is empty for this classroom "+room_id, Toast.LENGTH_SHORT).show();
}
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
Toast.makeText(ClassroomDashboard.this, "unable to read attadance data node", Toast.LENGTH_SHORT).show();
}
});
body_table.addCell(new Cell().add(new Paragraph("blimey")).setBorder(Border.NO_BORDER).setBackgroundColor(ColorConstants.WHITE).setFontColor(ColorConstants.BLACK).setTextAlignment(TextAlignment.CENTER));
document.add(bg_pdf_img.setFixedPosition(0,0));
document.add(header_pdf_img);
document.add(header_table);
document.add(body_table);
document.close();
Toast.makeText(this, "PDF created successfully in "+pdf_path, Toast.LENGTH_SHORT).show();
return 1;
}
