The XML options on DATASET and OUTPUT allow you to easily work with simple XML data. For example, an XML file that looks like this (this data generated by the code in GenData.ECL):

<?xml version=1.0 ...?>
<timezones>
<area>
  <code>
        215
  </code>
  <state>
        PA
  </state>
  <description>
        Pennsylvania (Philadelphia area)
  </description>
  <zone>
        Eastern Time Zone
  </zone>
</area>
<area>
  <code>
        216
  </code>
  <state>
        OH
  </state>
  <description>
        Ohio (Cleveland area)
  </description>
  <zone>
        Eastern Time Zone
  </zone>
</area>
</timezones>

This file can be declared for use in your ECL code (as this file is declared as the TimeZonesXML DATASET declared in the DeclareData MODULE Structure) like this:

EXPORT TimeZonesXML :=
          DATASET('~PROGGUIDE::EXAMPLEDATA::XML_timezones',
                  {STRING code,
                   STRING state,
                   STRING description,
                   STRING timezone{XPATH('zone')}},
                  XML('timezones/area') );

This makes the data contained within each XML tag in the file available for use in your ECL code just like any flat-file dataset. The field names in the RECORD structure (in this case, in-lined in the DATASET declaration) duplicate the tag names in the file. The use of the XPATH modifier on the timezone field allows us to specify that the field comes from the <zone> tag. This mechanism allows us to name fields differently from their tag names.

By defining the fields as STRING types without specifying their length, you can be sure you're getting all the data--including any carriage-returns, line feeds, and tabs in the XML file that are contained within the field tags (as are present in this file). This simple OUTPUT shows the result (this and all subsequent code examples in this article are contained in the XMLcode.ECL file).

IMPORT $;

ds := $.DeclareData.timezonesXML;

OUTPUT(ds);

Notice that the result displayed in the ECL IDE program contains squares in the data--these are the carriage-returns, line feeds, and tabs in the data. You can get rid of the extraneous carriage-returns, line feeds, and tabs by simply passing the records through a PROJECT operation, like this:

StripIt(STRING str) := REGEXREPLACE('[\r\n\t]',str,'$1');
RECORDOF(ds) DoStrip(ds L) := TRANSFORM
  SELF.code := StripIt(L.code);
  SELF.state := StripIt(L.state);
  SELF.description := StripIt(L.description);
  SELF.timezone := StripIt(L.timezone);
END;
StrippedRecs := PROJECT(ds,DoStrip(LEFT));
OUTPUT(StrippedRecs);

The use of the REGEXREPLACE function makes the process very simple. Its first parameter is a standard Perl regular expression representing the characters to look for: carriage return (\r), line feed (\n), and tab (\t).

You can now operate on the StrippedRecs recordset (or ProgGuide.TimeZonesXML dataset) just as you would with any other. For example, you might want to simply filter out unnecessary fields and records and write the result to a new XML file to pass on, something like this:

InterestingRecs := StrippedRecs((INTEGER)code BETWEEN 301 AND 303);
OUTPUT(InterestingRecs,{code,timezone},
       '~PROGGUIDE::EXAMPLEDATA::OUT::timezones300',
       XML('area',HEADING('<?xml version=1.0 ...?>\n<timezones>\n','</timezones>')),OVERWRITE);

The resulting XML file looks like this:

<?xml version=1.0 ...?>
<timezones>
<area><code>301</code><zone>Eastern Time Zone</zone></area>
<area><code>302</code><zone>Eastern Time Zone</zone></area>
<area><code>303</code><zone>Mountain Time Zone</zone></area>
</timezones>