updateButtonClicked

/**
	 * "Update" button is clicked
	 * @author	Andrey Zinovyev, Catherine Yu
	 * @date	1/7/2021
	 * @param file	 The CSV file that contains all the information on the chemicals
	 * @param date	 The current date
	 * @return void: Does not return anything
	 */
	public void updateButtonClicked(File file, String date) {
		
		// Create two Observable lists.
		ObservableList<editChemicalTable> itemSelected, allItems;
				
		// Get all the items in the table.
		allItems = chemicalTable.getItems();

		// Get the selected row.
		itemSelected = chemicalTable.getSelectionModel().getSelectedItems();

		// Create an array to store the information in the selected row
		String[] originalChemicalInformation = new String[6];
		// Populate the array based on the selected row of information in the TableView
		originalChemicalInformation[0] = itemSelected.get(0).getChemicalName();
		originalChemicalInformation[1] = itemSelected.get(0).getChemicalMass() + "";
		originalChemicalInformation[2] = itemSelected.get(0).getChemicalVolume() + "";
		originalChemicalInformation[3] = itemSelected.get(0).getChemicalFormula();
		originalChemicalInformation[4] = itemSelected.get(0).getDateOfEntry();
		originalChemicalInformation[5] = itemSelected.get(0).getDateOfExpiry();

		// If the text fields are empty, the information in the selected row will be placed into the text fields
		if (!chemicalExpiryInput.getText().contains("/") ) {
			// Store the information in the selected row into the text fields
			chemicalNameInput.setText(originalChemicalInformation[0]);
			chemicalMassInput.setText(originalChemicalInformation[1]);
			chemicalVolumeInput.setText(originalChemicalInformation[2]);
			chemicalFormulaInput.setText(originalChemicalInformation[3]);
			chemicalExpiryInput.setText(originalChemicalInformation[5]);
		} else {
			// Otherwise, the chemical is updated

			// Create an array to store all the updated information on the current chemical
			String[] updatedChemicalInformation = new String[6];
			// Populate the array based on updated information in the text fields
			updatedChemicalInformation[0] = chemicalNameInput.getText();
			updatedChemicalInformation[1] = chemicalMassInput.getText();
			updatedChemicalInformation[2] = chemicalVolumeInput.getText();
			updatedChemicalInformation[3] = chemicalFormulaInput.getText();
			// Set the entry date as the current date
			updatedChemicalInformation[4] = date;
			updatedChemicalInformation[5] = chemicalExpiryInput.getText();

			editChemicalTable item = new editChemicalTable();

			// Get the updated information entered into the text fields.
			item.setChemicalName(chemicalNameInput.getText());
			item.setChemicalMass(Double.parseDouble(chemicalMassInput.getText()));
			item.setChemicalVolume(Double.parseDouble(chemicalVolumeInput.getText()));
			item.setChemicalFormula(chemicalFormulaInput.getText());
			item.setDateOfEntry(date);
			item.setDateOfExpiry(chemicalExpiryInput.getText());

			// Get the updated items in the text fields and add them to the table.
			chemicalTable.getItems().add(item);

			try {
				// Delete the original row of information from the CSV file
				CSVCode.deleteFileData(file, originalChemicalInformation);

				// Add a delay in between deleting and adding to prevent any errors
				try {
					TimeUnit.SECONDS.sleep(1);
				} catch (InterruptedException e) {
					// Catch any exceptions
					e.printStackTrace();
				}

				// Add the updated information in the array into the CSV file
				CSVCode.addFileData(file, updatedChemicalInformation);
			} catch (IOException e) {
				// Catch any exceptions
				e.printStackTrace();
			}

			// Clear the text fields.
			chemicalNameInput.clear();
			chemicalMassInput.clear();
			chemicalVolumeInput.clear();
			chemicalFormulaInput.clear();
			chemicalExpiryInput.clear();

			// Remove the selected row's items.
			itemSelected.forEach(allItems::remove);
		}
	}