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Hack 24 Keep Track of Auctions Outside of eBay
Use eBay's auction-trackingtools, or create a flexible auction-watching tool better than
anything eBay has to offer.If
I bought everything on eBay I wanted, I would've
gone broke long ago. But I'm also a collector, and
as such, I routinely track many auctions in my various fields of
interest, whether or not I actually intend to bid on them.I would argue that keeping track of auctions is among your most
important tasks as a bidder especially for items
you've won if for no other reason than to
ensure that you eventually receive everything you've
paid for. Tracking auctions is also an essential part of sniping (see
[Hack #21]) as well as selling (see
[Hack #33]). If you're
really after something specific, you may want to track completed
auctions that didn't sell so you can find them
easily when they're relisted. And sometimes you may
want to keep track of an auction's progress purely
for the sake of curiosity.
3.6.1 Using eBay's Tracking Tools
The Bidding/Watching tab of My eBay is where
most people turn to track their auctions. The
Items I'm Bidding On list
and the Items I've Won and
Items I Didn't Win lists
are all updated automatically whenever you place a bid or an auction
on which you've bid closes, respectively. These
lists include all the vitals, such as the auction titles, amounts of
your bids, end dates, and closing prices.By default, the Items
I've Won and Items I Didn't Win
lists show only auctions that have ended in the past few days, but
you can increase their range to up to 30 days by typing the desired
number of days in the box at the top of each list. And like search
results, all the lists on this page can be sorted by clicking the
hyperlinked column headers.
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also on the Bidding/Watching page, is a very handy
tool, but it works somewhat differently from the others. It will
remain empty until you choose to
"watch" an auction: simply go to
any auction (or fixed-price listing) page and click
"Watch this item." A message then
appears confirming that item is now being tracked in My eBay; click
the link to view the updated list. The Watching list is easy to use
and adequate if you never track more than a few items at a time.
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3.6.2 If You Want It Done Right . . .
As useful as eBay's tools are, I've
found that none of them completely meets my needs. For example:You can watch a maximum of 30 auctions at a time. When you reach the
limit, you have to manually delete watched items before you can add
more.Auctions appear in the lists for no longer than 30 days, even though
they remain in the eBay system for about 3 months.You can't add completed auctions to your Watching
list (although closed auctions do remain in your Watching list for 30
days).There's no way to prioritize items in your Watching
list, which would be useful for differentiating items on which
you're planning to bid and those about which
you're simply curious.There's no way to add auctions to the Items
I've Won list, which would be useful if
you've decided to complete a transaction outside of
eBay.The Bidding/Watching page can be cumbersome to use. For example, the
way entries are divided into auctions won, auctions lost, etc., has a
certain logic to it, but doesn't necessarily end up
being as convenient as a single, unified list of auctions would be.
These limitations have prompted me to come up with something better:
a fully customizable, web-based, off-site list of auctions with none
of the limitations of eBay's tools. The following is
based on a tool I created for my own use and have used every day
since.There are two parts to this hack: a Perl script, used to store and
display your personal list of auctions, and the link, used to
activate the script and add the auction at which
you're currently looking.
3.6.3 The Link
The first task is to create an easy way to add any given auction to
your custom list, an alternative to the Watch
This Item link on auction pages. This is accomplished by placing the
following snippet of JavaScript in a button on your
browser's Links bar (make sure the text appears all
on one line):
javascript:void(win=window.open('http://www.ebayhacks.com/exec/track.pl?
do=add&auction='+location.href+'&title='+document.title,'Hack'))You can name the new link anything you like, such as
"Watch Auction" or simply
"Track." (See [Hack #13] for more information on the Links
bar.)The first few bits of the code are used to instruct your browser to
open a new browser window and execute the code inside the
parentheses, but it's the stuff that follows that
concerns us. First comes the URL of your tracking tool, so
you'll need to change
www.ebayhacks.com to the name of your
own server, /exec to the name of your executable
folder (often /cgi-bin), and
track.pl to the filename of your script (discussed
in the following section). The second half of the URL, after the
question mark (?), is composed of three arguments
that are passed to your script, separated by ampersands
(&):
do=add&auction='+location.href+'&title='+document.title
JavaScript automatically inserts the auction URL
(location.href) and page title
(document.title) as arguments to pass to the
script. One of the neat little tricks of this code is how it works
with eBay's auction URL, which also includes
arguments separated by ampersands:http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3125058177When this URL is passed to your script with the other arguments, it
is automatically split into these two arguments:
auction=http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem
item=3125058177
and thus the auction number is conveniently separated for us!
3.6.4 The Script
The second half of this hack is a script
written in Perl, which interprets the information it receives from
the JavaScript link (see the previous section), stores all your
auctions in a file, and then displays a properly sorted list.
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#!/usr/bin/perl
# *** includes ***
use Time::ParseDate;
use POSIX qw(strftime);
require("cgi-lib.pl");
&ReadParse;
# *** variables ***
$selfurl = "http://www.ebayhacks.com/exec/track.pl"; [1]
$localfile = "/usr/local/home/ebaylist.txt";
$timeoffset = 0;
$url = "http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=";
@formatting=("color=#EE0000 STYLE=font-weight:bold", [2]
"color=#000000 STYLE=font-weight:bold", "color=#000000");
$i = 0;
$exists = 0;
$numlevels = 2; [3]
# *** read stored list ***
open (INFILE,"$localfile");
while ( $line = <INFILE> ) {
$line =~ s/s+$//;
$i++;
($enddate[$i],$priority[$i],$item[$i],$title[$i]) =
split(",", $line, 4);
# *** see if passed auction number is in list already ***
if (($item[$i] ne ") && ($item[$i] eq $in{'item'})) { $exists = $i; }
}
close (INFILE);
# *** add latest auction to list, if valid ***
if (($in{'auction'} =~ "ebay.com") && ($in{'item'} != ") && ($exists==0)) {
$x = index($in{'title'}, "(");
$y = index($in{'title'}, ")", $x);
$z = index($in{'title'}, "-", $y);
$title = substr($in{'title'}, $z + 2); [4]
$enddate = parsedate(substr($in{'title'}, $x + 6, $y - $x - 7));
$i++;
($enddate[$i], $priority[$i], $item[$i], $title[$i]) =
($enddate, 2, $in{'item'}, $title);
}
elsif (($in{'do'} eq "promote")) {
$priority[$exists]--;
if ($priority[$exists] < 0) { $priority[$exists] = 0; }
}
elsif (($in{'do'} eq "demote")) {
$priority[$exists]++;
if ($priority[$exists] > 2) { $priority[$exists] = 2; }
}
elsif (($in{'do'} eq "delete")) {
splice @enddate, $exists, 1;
splice @priority, $exists, 1;
splice @item, $exists, 1;
splice @title, $exists, 1;
$i--;
}
# *** update list ***
if (($in{'do'} ne ")) {
open (OUTFILE,">$localfile");
for ($j = 1; $j <= $i; $j++) {
print OUTFILE "$enddate[$j],$priority[$j],$item[$j],$title[$j]n";
}
close (OUTFILE);
print "Location: $selfurlnn";
exit( 0);
}
# *** sort list ***
@idx = sort criteria 0 .. $i;
# *** display list ***
print "Content-type: text/htmlnn";
print "<table border cellspacing=0 cellpadding=6>n";
for ($j = 1; $j <= $i; $j++) {
$formatteddate =
strftime("%a, %b %d - %l:%M:%S %p", localtime($enddate[$idx[$j]]));
$formattedtitle = "<a href="$url$item[$idx[$j]]" target="_blank"><font [5]
$formatting[$priority[$idx[$j]]]>$title[$idx[$j]]</font></a>";
if (strftime("%v", localtime($enddate[$idx[$j]])) eq
strftime("%v", localtime(time))) {
$formattedtitle = "<li>" . $formattedtitle; [6]
}
if ($enddate[$idx[$j]] < time) {
$formattedtitle = "<strike>" . $formattedtitle . "</strike>"; [7]
}
else {
$timeleft = ($enddate[$idx[$j]] - time) / 60 + ($timeoffset * 60);
if ($timeleft < 24 * 60) {
$hoursleft = int($timeleft / 60);
$minleft = int($timeleft - ($hoursleft * 60));
if ($minleft < 10) { $minleft = "0" . $minleft; }
$formattedtitle = $formattedtitle . [8]
" <font size=-1>($hoursleft:$minleft left)</font>";
}
}
print "<tr><td>$formattedtitle</td>";
print "<td><font size=-1>$formatteddate</font></td>";
print "<td><a href="$selfurl?item=$item[$idx[$j]]&do=promote">+</a>"; [9]
print " | <a href="$selfurl?item=$item[$idx[$j]]&do=demote">-</a>";
print " | <a href="$selfurl?item=$item[$idx[$j]]&do=delete">x</a></td>";
print "</tr>n";
}
print "</table>n";
sub criteria {
# *** sorting criteria subroutine ***
return ($priority[$a] <=> $priority[$b] or $enddate[$a] <=> $enddate[$b])
}
Save this script as track.pl and place it in
your web server's cgi-bin
directory, as described in [Hack #94].
Note that the $selfurl and
$localfile variables [1] must be modified to match the URL of your script and the location of
the local file in which the auction titles are to be stored,
respectively. Also, you may need to adjust the
$timeoffset variable to compensate for the time
zone difference between eBay time (Pacific time) and your
computer's clock; e.g., enter 3
if you're in Eastern time (GMT - 5:00).
3.6.5 Running the Hack
With the script in place and the JavaScript link at the ready on your
browser toolbar, all that's left is to try it out.
Open any auction page on eBay and click the
"Track" link on your Links bar. A
new window will open, and the auction you were just looking at will
appear at the top of the list, as shown in Figure 3-3. Repeat this for as many auctions as you like;
there's virtually no limit. You can even track
completed auctions and auctions that you haven't
won.
Figure 3-3. Track and prioritize auctions with this flexible web-based tool
Click the title of any auction to open the eBay auction page in a new
window. Click the [x] link to delete the entry.Auctions can be prioritized; all new entries start out at the lowest
priority and are shown in normal font. Click the
[+] link to promote an auction and make its title
bold. Click [+] again to promote the auction to
the highest level and make its title red and bold. Likewise, click
[-] to demote any entry. Higher-priority items
appear higher in the list, and all auctions within a certain priority
level are sorted by their closing date. I use the lowest priority for
auctions on which I don't intend to bid, the medium
priority for items I want, and the highest priority for items
I've already bid on and won.
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3.6.6 Hacking the Hack
Naturally, you'll want to customize this hack to
suit your needs, which is really this tool's
greatest advantage over eBay's
Bidding/Watching page. Among the more
interesting ways to hack this script are the following:If you're familiar with HTML, you can add pictures
and text to your heart's content. Add shading and
even column headers (for sorting) to the table. Replace the
[+], [-], and
[x] links [9] with more
interesting icons, and add a splash of color to the page.You can have as many different levels of prioritization as you like.
Three levels suit my needs just fine, but you can add more by
increasing the $numlevels variable [3]. (Keep in mind that lower numbers mean a
higher priority.) The only other thing you'll need
to maintain is the @formatting array [2], which contains snippets of HTML code (one for
each priority level) that visually differentiate one priority level
from another. For details, look up the
<font> structure in any HTML documentation
(or see [Hack #40]).Using the $item[$idx[$j]] variable [4], you can also add links to bid, leave
feedback, and view the bid history.To support multiple users, include another argument in the JavaScript
link (Part 1), such as &user=cletus. Then,
simply append the username to the filename to create a different
auction list file [1] for each user, like
this:
$localfile = "/usr/local/home/ebaylist_L$in{'user'}.txt";For simplicity, the script retrieves the auction title [4] by parsing the arguments passed to it from theJavaScript link. The main caveat is that if the title contains an
ampersand (&) or pound sign
(#), the title will be broken apart, and all
you'll get is the first portion. Also, the script
determines the closing time and date by further parsing the title,
and may not work with titles from non-U.S. sites that use a different
date notation.A more bulletproof (and only slightly more complex) solution to both
of these problems would be to use the eBay API to retrieve the
auction title and end date, as described in [Hack #86]. This would also enable you to
reliably read the seller's name, the current price,
and other auction details, all without having to resort to parsing.The script also contains code to add a little
"richness" to the tool. For
example, completed auctions have crossed-out titles [7], auctions ending today are marked with round
bullets [6], and any auction ending within
24 hours shows the time left to bid [8].
I've found these additions to be quite helpful for
my purposes, but you may have different needs. For example, if
you're in front of the computer only during the day,
you can configure the script to highlight auctions ending after 5:00
P.M. so you know you'll have to bid early or set up
an automatic snipe (see [Hack #22]).The pop-up window can be customized by modifying the JavaScript code.
For example, add the following to the JavaScript line:
,'width=400,height=300,menubar=no,status=no,resizable=yes,scrollbars=yes'Place the code after 'Hack' but before the two
closing parentheses. Make sure to include the comma and enclose the
parameters as a whole in single quotes as shown. More information on
these parameters can be found in any JavaScript documentation, under
the window.open statement.
