Charts - custom voices on Legend

Question

Hi all,
when I create a chart with APEX it request to me a query which returns voices "*link, label, value1, value2, ...*".
The problem with that is the fact that voice in chart's legend, when showed, lists "*ICON value1, ICON value2, ...*".
What I need is to replace "*value1, value2, ...*" in legend with more descrictive voices...
Currently I used to customize XML and put FIXED legend voices and icon totally customized, like:
<legend enabled="true" position="bottom" align="spread" ignore_auto_item="true" align_by="chart" elements_align="center">
     <title><text>DAYS</text></title>
     <columns_separator enabled="false"/>
     <font family="Arial" size="10" color="0x000000" />
     <items>
          <item>
               <icon type="SeriesIcon" color="0x33CCCC"><marker enabled="true" /></icon>
               <text>{%Icon} &DATE_DAY1.</text>
          </item>
         <item>
               <icon type="SeriesIcon" color="0xFF9900"><marker enabled="true" /></icon>
               <text>{%Icon} &DATE_DAY2.</text>
          </item>
         <item>
               <icon type="SeriesIcon" color="0xCC0000"><marker enabled="true" /></icon>
               <text>{%Icon} &DATE_DAY3.</text>
          </item>
         <item>
               <icon type="SeriesIcon" color="0x009900"><marker enabled="true" /></icon>
               <text>{%Icon} &DATE_DAY4.</text>
          </item>
         <item>
               <icon type="SeriesIcon" color="0x0033FF"><marker enabled="true" /></icon>
               <text>{%Icon} &DATE_DAY5.</text>
          </item>
     </items>
</legend>Where &DATE_DAY&lt;X&gt;. are ORACLE APEX APPLICATION ITEMS filled with a PL/SQL procedure.
But this has the effect that passing mouse pointer on legend voices, doesn't highlight relative elements inside the chart itself.
And I wish it a lot, if possible.
The other solution could be to overwrite APEX automatic XML generation procedure by writing my own PL\SQL procedure to do it. As I did to implement threshold in some Bars Charts (still not in this one... this is a Lines Chart).
But I fear it would generate much more text than I can manage, because my chart involve 5 series (5 lines, 1 x 5 days, so 5 legend voices) for 48 points each (1 value every 30 mins).
And it's lot of XML text.
Thank you! :)

Answer 1

You was right. You could work by simply substituting "+value1, value2, value3, ...+" alias with custom alias of your wish. :)
The pity, as said, is that it couldn't apply to my sistuation, 'cause my legend voices have to be variable dates. And I can't used variables as queries alias, it seems.
The sole problem with the procedure I'm using now, is that I have to launch such query on around 18,000,000 records, and it takes up to 30 seconds.
Seeing I launch the "getdata();" JavaScript function at the load of the page, it means it needs 30 seconds before the page is ready.
I use this PL/SQL to populate it:
declare
    type l_dates is table of date index by binary_integer;
    l_date_days         l_dates;
    l_data              clob;
    l_chart_data_xml    varchar2(32767);
    l_data_serie1       clob;
    l_data_serie2       clob;
    l_data_serie3       clob;
    l_data_serie4       clob;
    l_data_serie5       clob;
begin
    -- Fill 5 most recent dates in variables
    for cd in (select rownum RN, DATA_DAY as DAY
                from
                 (select to_date(DAY, 'MM/DD/YY') as DATA_DAY
                 from STORED_DAYS
                 order by DATA_DAY desc)) 
    loop
        if cd.RN = 1 then
            l_date_days(5) := cd.DAY;
        elsif cd.RN = 2 then
            l_date_days(4) := cd.DAY;
        elsif cd.RN = 3 then
            l_date_days(3) := cd.DAY;
        elsif cd.RN = 4 then
            l_date_days(2) := cd.DAY;
        elsif cd.RN = 5 then
            l_date_days(1) := cd.DAY;
        end if;
    end loop;
    -- Initialize Clobs   
    dbms_lob.createtemporary( l_data, FALSE, dbms_lob.session );
    dbms_lob.open( l_data, dbms_lob.lob_readwrite );
    dbms_lob.createtemporary( l_data_serie1, FALSE, dbms_lob.session );
    dbms_lob.createtemporary( l_data_serie2, FALSE, dbms_lob.session );
    dbms_lob.createtemporary( l_data_serie3, FALSE, dbms_lob.session );
    dbms_lob.createtemporary( l_data_serie4, FALSE, dbms_lob.session );
    dbms_lob.createtemporary( l_data_serie5, FALSE, dbms_lob.session );
    dbms_lob.open( l_data_serie1, dbms_lob.lob_readwrite );
    dbms_lob.open( l_data_serie2, dbms_lob.lob_readwrite );
    dbms_lob.open( l_data_serie3, dbms_lob.lob_readwrite );
    dbms_lob.open( l_data_serie4, dbms_lob.lob_readwrite );
    dbms_lob.open( l_data_serie5, dbms_lob.lob_readwrite );
    l_chart_data_xml := '      <data>'||chr(10);
    dbms_lob.writeappend( l_data, length(l_chart_data_xml), l_chart_data_xml);
    -- Open Series
    l_chart_data_xml := '        <series name="'||to_char(l_date_days(1),'MM/DD/YY')||'" type="Line" color="0x33CCCC">'||chr(10);
    dbms_lob.writeappend( l_data_serie1, length(l_chart_data_xml), l_chart_data_xml);
    l_chart_data_xml := '        <series name="'||to_char(l_date_days(2),'MM/DD/YY')||'" type="Line" color="0xFF9900">'||chr(10);
    dbms_lob.writeappend( l_data_serie2, length(l_chart_data_xml), l_chart_data_xml);
    l_chart_data_xml := '        <series name="'||to_char(l_date_days(3),'MM/DD/YY')||'" type="Line" color="0xCC0000">'||chr(10);
    dbms_lob.writeappend( l_data_serie3, length(l_chart_data_xml), l_chart_data_xml);
    l_chart_data_xml := '        <series name="'||to_char(l_date_days(4),'MM/DD/YY')||'" type="Line" color="0x009900">'||chr(10);
    dbms_lob.writeappend( l_data_serie4, length(l_chart_data_xml), l_chart_data_xml);
    l_chart_data_xml := '        <series name="'||to_char(l_date_days(5),'MM/DD/YY')||'" type="Line" color="0x0033FF">'||chr(10);
    dbms_lob.writeappend( l_data_serie5, length(l_chart_data_xml), l_chart_data_xml);
    -- Loop through series data
    for c1 in (select
     substr(DATE_TIME, -8, 8) as label,
     max(decode(to_date(substr(DATE_TIME, 0, 8),'MM/DD/YY'),l_date_days(1),KPI_VALUE,null)) value1,
     max(decode(to_date(substr(DATE_TIME, 0, 8),'MM/DD/YY'),l_date_days(2),KPI_VALUE,null)) value2,
     max(decode(to_date(substr(DATE_TIME, 0, 8),'MM/DD/YY'),l_date_days(3),KPI_VALUE,null)) value3,
     max(decode(to_date(substr(DATE_TIME, 0, 8),'MM/DD/YY'),l_date_days(4),KPI_VALUE,null)) value4,
     max(decode(to_date(substr(DATE_TIME, 0, 8),'MM/DD/YY'),l_date_days(5),KPI_VALUE,null)) value5
    from INPUT_CSV
    where HOST_NAME = :THE_HOST_NAME
     and KPI_NAME = :THE_KPI_NAME
     and DEVICE = :THE_DEVICE
    group by substr(DATE_TIME, -8, 8)
    order by LABEL) 
    loop
        -- Fill Series       
        l_chart_data_xml := '          <point name="'||c1.label||'" y="'||c1.value1||'" ></point>'||chr(10);
        dbms_lob.writeappend( l_data_serie1, length(l_chart_data_xml), l_chart_data_xml);
        l_chart_data_xml := '          <point name="'||c1.label||'" y="'||c1.value2||'" ></point>'||chr(10);
        dbms_lob.writeappend( l_data_serie2, length(l_chart_data_xml), l_chart_data_xml);
        l_chart_data_xml := '          <point name="'||c1.label||'" y="'||c1.value3||'" ></point>'||chr(10);
        dbms_lob.writeappend( l_data_serie3, length(l_chart_data_xml), l_chart_data_xml);
        l_chart_data_xml := '          <point name="'||c1.label||'" y="'||c1.value4||'" ></point>'||chr(10);
        dbms_lob.writeappend( l_data_serie4, length(l_chart_data_xml), l_chart_data_xml);
        l_chart_data_xml := '          <point name="'||c1.label||'" y="'||c1.value5||'" ></point>'||chr(10);
        dbms_lob.writeappend( l_data_serie5, length(l_chart_data_xml), l_chart_data_xml);
    end loop;
    -- Close Series
    l_chart_data_xml := '        </series>'||chr(10);
    dbms_lob.writeappend( l_data_serie1, length(l_chart_data_xml), l_chart_data_xml);
    l_chart_data_xml := '        </series>'||chr(10);
    dbms_lob.writeappend( l_data_serie2, length(l_chart_data_xml), l_chart_data_xml);
    l_chart_data_xml := '        </series>'||chr(10);
    dbms_lob.writeappend( l_data_serie3, length(l_chart_data_xml), l_chart_data_xml);
    l_chart_data_xml := '        </series>'||chr(10);
    dbms_lob.writeappend( l_data_serie4, length(l_chart_data_xml), l_chart_data_xml);
    l_chart_data_xml := '        </series>'||chr(10);
    dbms_lob.writeappend( l_data_serie5, length(l_chart_data_xml), l_chart_data_xml);
    -- Close and commit XML data
    dbms_lob.writeappend( l_data, length(l_data_serie1), l_data_serie1 );
    dbms_lob.writeappend( l_data, length(l_data_serie2), l_data_serie2 );
    dbms_lob.writeappend( l_data, length(l_data_serie3), l_data_serie3 );
    dbms_lob.writeappend( l_data, length(l_data_serie4), l_data_serie4 );
    dbms_lob.writeappend( l_data, length(l_data_serie5), l_data_serie5 );
    l_chart_data_xml := '  </data>';
    dbms_lob.writeappend( l_data, length(l_chart_data_xml), l_chart_data_xml );
    l_chart_data_xml := wwv_flow.do_substitutions(wwv_flow_utilities.clob_to_varchar2(l_data));
    -- Close Clobs   
    dbms_lob.close( l_data );
    if l_data is not null then dbms_lob.freetemporary(l_data); end if;
    dbms_lob.close( l_data_serie1 );
    dbms_lob.close( l_data_serie2 );
    dbms_lob.close( l_data_serie3 );
    dbms_lob.close( l_data_serie4 );
    dbms_lob.close( l_data_serie5 );
    if l_data_serie1 is not null then dbms_lob.freetemporary(l_data_serie1); end if;
    if l_data_serie2 is not null then dbms_lob.freetemporary(l_data_serie2); end if;
    if l_data_serie3 is not null then dbms_lob.freetemporary(l_data_serie3); end if;
    if l_data_serie4 is not null then dbms_lob.freetemporary(l_data_serie4); end if;
    if l_data_serie5 is not null then dbms_lob.freetemporary(l_data_serie5); end if;
    -- Set XML data
   :DATA_DATA := l_chart_data_xml;
end;Where :THE_HOST_NAME , :THE_KPI_NAME and :THE_DEVICE are Applications Items populated elsewhere.
And DATE_TIME is (unluckily, and not by my choice) a varchar2 with textual date and time.
It's similar to your, but modified at my needings.
I'm not a PL/SQL expert, so maybe it could be wrote better.
Anyway currently it's ok for my customer to wait 30 seconds: he know about so much data amount.
And in the new "release" of the whole system we're buinding up, it seems records lowered to 12,000,000. It's already better. :)