ABAP_to_the_Future

11
ABAP2XLSX
CREATE OBJECT lo_excel_writer TYPE zcl_excel_writer_2007.
ld_xml_file = lo_excel_writer->write_file( lo_excel ).
Listing 11.3 Converting an Excel Object to XML
The interface ZIF_EXCEL_WRITER defines the methods and attributes for converting
an Excel object into an XML file. Theref ore, if a new version of Excel comes out
and it turns out to be radically different, then a new class is created that handles
the new version, and the calling program do es not need to change at all, except
that the CREATE OBJECT statement has to refer to ZCL_EXCEL_WRITER_2057 or whatever
the new Excel version will be. As an example, if the spreadsheet is to be
macro-enabled, then the object has to be created as TYPE ZCL_EXCEL_WRITER_XLSM.
If you drill down into the WRITE_FILE method, then you’ll see a series of steps that
build up the exact folder structure you saw earlier (Figure 11.3) when you looked
at your zipped spreadsheet file—that is, first a ZIP object is created, and then the
folders and XML files are append ed to that ZIP object. The ZCL_EXCEL_WRITER
class uses standard SAP mechanisms to build up an XML structure, with the result
coming out as an XSTRING object, which is essentia lly an enormous amount of
information in a really long string.
As mentioned previously, the settings for the rows that repeat the top when
printing were stored in the workbook file within the xl folder. If you look inside
the WRITE_FILE method, you’ll see a submethod called CREATE_XL_WORKBOOK,
which does what you would expect—that is, it creates the XML file called “workbook”
that lives in the xl folder.
Downloading the Spreadsheet to the Frontend
Once you have an XML file containing the spreadsheet information, you can
export this file from the ABAP system toa directory on your local machine, where
the file will look just like a spreadsheet that has been create d manually in Excel
and then saved.
The code in Listing 11.4, which shows how to download the spreadsheet, consists
entirely of calls to standard SAP methods. First, the XML string is converted into
so-called raw data; then, the user is asked where he wants to save the file; finally,
the file is downloaded in the normal manner.
DATA: lt_rawdata TYPE solix_tab,
ld_bytecount TYPE i,
ld_filename TYPE string,
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