in reply to Re^4: Setting flags in a conditional
in thread Setting flags in a conditional

BrowserUK, that's a good tip. Upon looking at the results, it occurs to me that no ships have a ':' in their name. But it's not clear to me how to parse for a colon whilst in the loop. As you say, @$row is an array; but I won't know what the element number is going to be from run to run.

Can I do it this way at all?

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Re^6: Setting flags in a conditional
by BrowserUk (Patriarch) on Mar 20, 2008 at 23:04 UTC
    As you say, @$row is an array; but I won't know what the element number is going to be from run to run.

    You have a pretty deep misunderstanding of the code you are using. $table->rows() returns a list of arrays. Ie. $row is an array reference representing the fields (or columns) of each row of the table.

    So whilst the position (row number) of the row containing the text Ships in port or not reporting today: will vary from run to run. The field or column within that row that contains the text will not.

    I used the following code to dump all the tables from the url you posted in another thread to the screen, with '|' between each element of the rows: 

    #! perl -slw
use strict;
use LWP::Simple;
use HTML::TableExtract;

my $te = new HTML::TableExtract;
$te->parse( get( 'http://www.sailwx.info/shiptrack/cruiseships.phtml' 
+) );

for my $table ( $te->tables ) {
    print "\n-----------\n";
    for my $row ( $table->rows ) {
        local $^W;
        print join '|', @$row;
    }
}

    [download]

    Redirecting the output of that, junk | more, I got: 

    ...
-----------

Ship|last reported (UTC)|position|Callsign
BATFR20|2008-Mar-20 2100|N 43░00', E 005░36'|BATFR20
BATFR21|2008-Mar-20 2100|N 41░36', E 008░24'|BATFR21
BATFR22|2008-Mar-20 2100|N 42░54', E 005░54'|BATFR22
...
Carribean Princess|2008-Mar-19 0600|N 19░18', W 065░18'|ZC
+DG8
Prinsendam|2008-Mar-19 0300|N 27░24', W 040░24'|PBGH
Ships in port or not reporting today:|||
TUSTUMENA|2008-Mar-18 1700|N 60░48', W 147░12'|WNGW
Oosterdam|2008-Mar-18 0800|N 23░00', W 107░48'|PBKH
...

    [download]

    From the empty fields on the end of Ships in port or not reporting today:|||, I can tell that the text that marks the transition from those ships at sea, to those in port, is returned in $row->[ 0 ].

    So your test becomes: 

    ...
for my $row ( $table->rows ) {
    if( $row->[ 0 ] ne 'Ships in port or not reporting today:' ) {
    ...

    [download]
    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
[d/l]
[select]
      Oh! I see!

      After reading the docs and looking at the examples, I somehow managed to walk away with the impression that the element was dealing with the row and not the column of the table. I'm not sure how that happened, but thanks for setting me straight.

      I suppose if a monk has to have an epiphany, Maundy Thursday in Holy Week is a good time to have one. Thanks, O Sagacious one. (Okay, I had to work hard to come up with a word that references your level).

      I will play with the code and try to deepen my understanding, because this is a fundamental.

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