Hacks 1917 Industrial.. Strength Tips and Tools [Electronic resources] نسخه متنی

Hack 85 Automatically Keep Track of Auctions You've Won

Maintain a permanent record of everything
you've ever purchased.

Since eBay keeps auctions on site
only for about 90 days and lists them in My eBay for only 30 days,
all bidders should maintain permanent, off-site records of the items
they've purchased.

As long as you keep all email you've received, as
described in the Preface of this book, you'll always
have records of the item numbers, titles, seller IDs and email
addresses, and closing prices of the items you've
won. But this data is stored in a less-than-convenient format, and
the descriptions aren't stored at all.

Here's a script that will automatically retrieve and
store details for every auction you've won:

#!/usr/bin/perl
require 'ebay.pl';
$today = &formatdate(time);     [1]
$yesterday = &formatdate(time - 86400);     [2]
my $rsp = call_api({ Verb => 'GetBidderList',     [3]
DetailLevel => 32,
UserId => $user_id,
SiteId => $site_id,
EndTimeFrom => $yesterday,
EndTimeTo => $today,
});
if ($rsp->{Errors}) {
print_error($rsp);
} else {
foreach (@{$rsp->{BidderList}{Item}}) {
my %i = %$_;
($highbidder, $title, $id) = @i{qw/HighBidderUserId Title Id/};     [4]
if ((! -e "$localdir/$id") && ($highbidder eq $user_id)) {     [5]
my $rsp = call_api({ Verb => 'GetItem',     [6]
DetailLevel => 2,
Id => $id
});
if ($rsp->{Errors}) {
print_error($rsp)
} else {
my %i = %{$rsp->{Item}[0]};
my ($price, $currency, $seller, $title, $description) =     [7]
@i{qw/CurrentPrice CurrencyId Seller Title Description/};
open (OUTFILE,">$localdir/$id");     [8]
print OUTFILE "[$id]\n";
print OUTFILE "title=$title\n";
print OUTFILE "seller=".$seller->{User}{UserId}."\n";
print OUTFILE "price=$currency$price\n";
print OUTFILE "description=$description\n";
close (OUTFILE);
}
}
}
}

The GetBidderList API verb, called on line [3], returns a maximum of 200 items, but
doesn't support paging like
GetSearchResults (see [Hack #83]). This means that we need to be a
little creative. So instead of trying to grab as many listings as
possible, we grab only the auctions that have ended in a certain
interval, say, a day. (If you bid infrequently, you can change this
to a week or even a month, and help keep down your API calls). So, we
set the EndTimeTo and
EndTimeFrom fields to today's and
yesterday's dates, respectively. The
formatdate subroutine is used on lines [1] and [2] to convert the Perl dates to something eBay understands.

Next, the script runs through the list of auctions
you've bid on and retrieves [4] the high bidder, title, and item number for
each. (We don't actually use the title here, but
it's nice to have.)

On line [5], a check is performed to see if
the auction has been recorded previously and if
you're indeed the high bidder. Note that since
we're using a DetailLevel of
32 (specified on line [3]), we get back an "abbreviated
results set" from which, as the documentation
explains, the user ID of the high bidder is retrieved with the
HighBidderUserId tag. We could also use a
DetailLevel of 0, but
we'd have to deal with the
HighBidder hash (see [Hack #84] for more information on container
nodes). Refer to the API documentation for the somewhat confusing
circumstances surrounding the DetailLevel tag with
regards to GetBidderList.

Finally, the auction details for each item are retrieved with
GetItem (line [6] and
then line [7]). Note that the
DetailLevel for this call is set to
2 to retrieve the descriptions as well, as
described in [Hack #84].

The $description variable contains the raw description, including any HTML code. See [Hack #90] for details on extracting plain text from HTML code.

Line [8] then saves the retrieved data into
a file, named for the item number of the listing. Naturally, you can
retrieve and store as many or as few fields as you like and store
them in whatever format is convenient, such as a database,
comma-delimited (CSV) text file, or the generic format used here.

See [Hack #17] for information on
scheduling the script to run at regular intervals. Since the script
retrieves only auctions that have ended in the last 24 hours, this
script should be run once a day, every day. If you want to run it
less (or more) often, just change the EndTimeTo
and EndTimeFrom fields accordingly.