any tips for for a weary researcher?

David & Joel – Thanks. By the time I’m done, I’m hoping I can make “Zillow data porn” look like a Disney movie. I think this kind of thing is the tip of iceberg for us MLS/IDX search vendors.

I love how you can get Zestimates on each individual property. That’s a incredibly powerful piece of information.

FYI – We will have a developer support forum up in a week or so – when we do, it would be great if you could share some of your experiences with the other dev’s. This will also give you the opportunity to log feature requests and suggestions.

It would be fantastic to meet you next week – I’ll ask Mark to introduce us if I’m around.

As of right now, it’s not easily embeddable into any site, other than Zearch-compatible MLS search engines (which in my opinion, there aren’t enough of in the world today, but that’s a problem I’m working on solving) .

Essentially, the brain of the control is an ASP.net dynamic image, which takes in various query string parameters. Depending on what was passed in, it calls either the GetChart or GetRegionChart Zillow web service, gets the url you return. If the url isn’t there in the response XML, I generate a dynamic error chart on the fly (w/ a pretty Zillow logo & a friendly error message), otherwise I use the url you gave me, make a another http request to get the images bits, and send them down to the browser. That way the browser just has to set the src attribute on the image correctly, instead of making XMLHTTP calls, using XML DOMs on the browser, exposing my ZillowWebServiceID on the client, etc. Save the wacky AJAX for when I really need it.

The downside is that I’m currently not preventing somebody from using my dynamically generated image on there, so you don’t need a ZillowWebServiceID to render my charts (which call your charts). I suspect it’s possible to block that problem if I look at the HTTP request headers that the browser sends me, and if somebody is requesting an image from a site I didn’t write, I send down a Caffeinated Software ad instead of a Zillow chart. I don’t know if this implementation decision will be an issue or not, but last time I got creative, Mark informed me I was causing a measurable load on your servers.

I’m not a master of open source software stacks. It’s not that I don’t want to be (I’m reading, softiesonrails.com) but keeping up with Redmond is a full time job. So maybe Garrett or the engineer who implemented the chart rendering should know what the PHP/Tapestry/J2EE/Rails equivalents to dynamic images are. (Or conversely you change the web service, so it’s just an url to a dynamic image and make life easy for the amateur web developer).

The heart is an ASP.net WebControl that depending on the page it’s invoked from, generates locations from an MLS listing search result page or from an MLS listing details page. All that stuff is tied to my MLS DB and wouldn’t port very well. We can throw away that part of the web control and keep the HTML though for your Labs, sample code, etc.

BTW, the year parameter isn’t part of your Chart APIs. I had to hack up the response urls, and replace the chartDuration parameter as needed to pull that trick off. You might want to fix that otherwise somebody will accuse me of using undocumented APIs or some such.

I’m meeting up with Mark Eamer for lunch next Thursday, so if any Zillow folks want to join us, we can brainstorm other ideas…

Drew M,

It’s my coding bug and your data bug.

When the control can’t map an MLS address to a Zillow Property ID, I think my control just shows the USA RegionChart, instead of an error chart. (I just got this bad boy working with Zesimates this morning, so I haven’t had time to let it bake yet).

On other times, when I do get a Zillow Property ID, the Zestimate value displayed in the chart is significantly different than the MLS# listprice of a property. It’s not really a Zillow bug, as much as it is a bad data error on your side.

In both cases, the Zestimate chart doesn’t match what the user expects and user is gonna go, “huh?”.

I guess this little toy, makes it easier for the Zillow testing dept to find bad Zestimate evaluations in greater Seattle (or for local agents to realize the listing agent is smoking something funny or entering bad data in the MLS).

Ardell,

When your ready to drop your Logical Dog off at the kennel and get Caffeinated, you know my number. BTW, how many “rules” did I break this time?