Sunday, November 25, 2007

Downloading Data to Your Real Estate Site the New Way

RETS (Real Estate Transaction Standard)

A few months ago I found out that my MLS (Sandicor) supports a new data transmission standard for IDX web sites called RETS. That sounds really boring, but it is really great, and here's why:










Old IDX WayNew RETS Way

In the past, we had to download data via FTP. These FTP files were created by the MLS around midnight, and then you could download them around 2:30am. That was the only update you could get all day.
With RETS, you can query the MLS servers for the updates in the past 3 hours. This now allows my web sites to have nearly up-to-the-minute information for our users
The old FTP files were tab-delimited text files and you pulled with an FTP client. This was a compact and effective way to transmit the information when Internet connections were slow. Unfortunately, the information was encoded (A=Ocean View, B=Canyon View, C=Park View) for the various fields. One had to write the decoding programs and maintain them.
The new way is with a SOAP service call which uses http (the web browser protocol). That sounds complicated, but what it really means is that you can specify what you want in the URL/Address that you are requesting. For example, if you only want 3 fields of data, just ask for the three fields and that's all you get instead of having to download the one massive file. If you only want updates for the last two hours, ask for them. AND, if you want all the fields decoded for you, just say so in the web address! No more maintaining the decoding logic when they add a new option.
The old way required you to parse the entire update file.Since you can ask for just the updates, you can have impose a smaller update requirement and just update those fields that need to be updated. Also, in our MLS (Tempo software from MarketLinx), the ModifiedDate field now has a timestamp so you now EXACTLY if your entry in your database is up to date. In the old FTP file, it was just a date stamp, and experience taught me that agents may update a listing 2 or 3 times when they are editing/previewing.
I also found that downloading photographs via the FTP servers was a bit of a problem. The technology was all there, but photos could be corrupted or missing. This was probably due to some bug in the copying process because they copied all the photos to a holding place.
With RETS I encounter fewer problems. Getting a photo is simply another URL request just like getting data, and since there is no holding place, there seem to be fewer problems.

Last week, our MLS sent all the people pulling IDX data an email indicating that they would be discontinuing the IDX data feed in Q1. I had already written the programming, so I completed the conversion to the new approach in a couple of days. So my site now uses RETS exclusively for updates.

For those of you who like the old approach, there is one other security benefit to the MLS. Every request has to be uniquely authenticated with your individual username/password. If someone starts handing out their username/password to a bunch of people, the overuse of the account will be immediately detected and a halt will be put to it. It's understandable why that's important to the MLSes.

Switching over to RETS is probably wise because this is the way for the MLS to provide all sorts of improvements without disrupting existing processes (admittedly once you are switched over). From the NAR meeting about a week ago, it sounds like over half of the MLSes support RETS, though some of them are not advertising it. So, if you want to switch your website over, ask your MLS about this new technology.

NOTE: Programming SOAP services with authentication and everything IS a bit on the complicated side. However, there are programs that you can set up a scheduled data pull, and then it creates a file on your machine or server much like the FTP pull. (Example: RETSconnector.com)

NOTE: If you are a real estate agent and doing your web site development in ColdFusion and are having any difficulties implementing RETS, contact us and I'll have my husband follow up with you. He's the programmer in the family.

Margaret Hokkanen

www.EncinitasCarlsbad.com

2 comments:

Monsanto said...

Wow! It seems you have dealt with my situation exactly. I am working with clients in North Texas (Dallas) to move to a RETS standard. We are using ColdFusion. I would love to know which programs you used for automating the updates into the system. Can you comment?

Anonymous said...

Our web sites are completely custom sites that I engineered myself. I programmed all the logic myself to pull the updates; fortunately RETS is fairly straightforward, and a decent programmer should have few problems. The major issue is the authentication piece.