--- title: Playing with map data from Zillow and the Google Maps API slug: playing-with-map-data-from-zillow-and-the-google-maps-api published_at: 2021-09-18 01:52:06 +0000 updated_at: 2026-03-04 20:13:54 +0000 summary: description: tags: [cjav_dev, web development tutorials, web development for beginners, vim, ruby, rails, javascript] views: 2312 author: CJ Avilla url: https://www.cjav.dev/videos/playing-with-map-data-from-zillow-and-the-google-maps-api youtube_url: https://www.youtube.com/watch?v=YltdJFlm_Xs youtube_id: YltdJFlm_Xs embed_url: https://www.youtube.com/embed/YltdJFlm_Xs thumbnail_url: https://i.ytimg.com/vi/YltdJFlm_Xs/hqdefault.jpg type: video --- # Playing with map data from Zillow and the Google Maps API *Published: September 18, 2021* *Views: 2312* ## Watch [Watch on YouTube](https://www.youtube.com/watch?v=YltdJFlm_Xs) [![Playing with map data from Zillow and the Google Maps API](https://i.ytimg.com/vi/YltdJFlm_Xs/hqdefault.jpg)](https://www.youtube.com/watch?v=YltdJFlm_Xs) ## Description ## Transcript hey what's up welcome back in this episode we're just going to play around a little bit with the data that you can get from zillow um they have an official api but i find that it's super limiting and it really just gives you search results and what i want to see is this map that they have on zillow but i want to see it with instead of just like a little icon for the school i want to know the rating the like 10 out of 9 out of 10 or you know 7 out of 10 or whatever i want to see that on the map i don't want to just see the this little head on the map so i i don't know if we want to just hack this from the browser or play around just to kind of like mess around with it directly here but what i wanted to do is just the first thing i do generally when i'm trying to figure out how i can get out this data is i'll open the dev console so on this page you can you can open this up with command option i on mac you can right click and inspect and when you're viewing some data like this you'll see that like as you move the map around api calls are being fired off sometimes those are going to be like done over web sockets or something you can also filter out those responses sometimes you also need to like refresh the page so you can see all of the network requests and you can preserve the log for those and there's a ton that's coming down here we've got um yeah just there's just a whole bunch of api calls that are firing off and so one thing that you might want to do is filter off to exclude like jpegs or pings or whatever scripts pngs fetch etc or actually we want fetch we want we want the xhrs because generally when you're using they're using google maps here on the background you can see map data 2021 they're going to be fetching some json from some service somewhere and then loading that onto the map using javascript at some point and what's really bad about their public api or that makes it frustrating to work with is it doesn't give you json it gives you back xml and so what i wanted to do is just kind of like poke around the data that you can get back when you're fetching some results so we see this get search page state and there's like a whole bunch of arguments that are being passed in here and the data that you get back you can look at the response tab um well sometimes you can preview it sometimes you can't i guess my guess is that there's like too much data so if we scroll like way in so there's just like fewer results and then if we scroll the bottom my guess is that we're going to see some other get page results okay so now we can see the response and here's the preview so we've got information about the user the school results so i turned on the schools by like messing around here and in the school results we can see there's two schools academy of learning and technology and the high school version of academy and learning technology and they are not rated so what i wanted to do was just take this api call and reproduce it locally and try to figure out what are what all the arguments are that are being passed in when this get request is happening so from the from the headers tab here we can see all the general information about the request we see the url to which the request was sent then we see that it is a get method we got back a 200 status code here's the ip address and the port and here's a bunch of headers so what i want to do is i'm just going to grab this whole url and i am going to open up postman so this is odd the zoom in hotkey doesn't work but okay so once we're zoomed in we've got a new collection here let's add a new request and i'm just going to say this is like fetch page i don't actually know what the stuff on the page is and then hit enter and we can actually see the request the the request went out and we got back some results so we see the request id is six and we can see all of the results down here this is the json that was returned and we can also see the search query state is this giant value that's being passed along in the query string and i i recognize this as some sort of base64 encoded something so we might just say like um url decoder and then we can paste in that value and say decode and here we go we've got back something and it looks like it's actually json being passed as like just url encoded json as one of the query string values that's being passed and we get we're passing in a map bounds for left and right we're passing in um i'm sorry east west south and north that's kind of like all of our corners of the map we have a zoom level and so we've got these school results and those give us the lat long attendance zones etc etc so um yeah so that's how we would just kind of reverse engineer i guess this get page state thing that's firing on on zillow so why don't we try and let's try and mess around with the map bounds i think and um yeah let's let's uh let's grab some some bigger map bounds so let's zoom all the way out um so we will zoom out out out as we zoomed so far out there was a ton of data and i'm sure we were like hitting some sort of memory limits or something um so what we really want is just this uh sort of the the the pa the pagination or the page state query string variable when we're zoomed further out so that we can pipe this into our query here and now we should be able to see yeah we see a much bigger json file that has 36 000 lines all right so let's just take a look and see if we can take this json file and use it to plot some stuff on a map so we will say we're going to save the response to a file response.json in alright so we'll jump into that directory and we have our response there now what i think might make sense is to create an index.html and try to figure out how to add a map to this page with google maps so let's go look at the google maps api and we'll pull up the documentation for this i know that you you have to have an api key now i believe to get this up and running okay we've got our map we've got our map height oh your api key click to insert okay so i'm inserting that with my api key and now we should be able to load this map maybe oh we got to restart our server and nothing okay so then we have our map element okay so here's where we have to like actually create the map all right so we'll come over here we'll write some javascript in here oh this is okay so this was what was we were just not calling a knit map okay sources index.js okay oh as html elements this is another uh okay that was another that was another typescript thing that we didn't actually need okay so we are zoomed in on a very specific point um it says google is not defined even though we're loading it after all right so we have a map it's zoomed in on this location we actually want to center it based on our response json so i have this giant json file i'm in vim i'm actually going to just visually select the whole thing and then pipe it to jq and it should pretty print it so that's a nice way to format json is just using jq okay so we've got some map state and this is at least this gives us a lat long that we could that we could pin to so let's do that we'll just say this is our lat and our long is this ish and that should at least give us a starting point and then the zoom i think was level eight but we'll see so if we refresh the page here i don't know if we need to start this over okay cool so this is in the right the right-ish spot okay um we don't actually need the pin there though so what we can do is we can just remove the marker and okay so now we've got a map showing up it's roughly in the spot that we want we want to like read in this json response and then do something with it so i think if i go to like slash response.json yeah okay so that pulls all the json data and then if i wanted to like iterate over it so inside of index.js here what i want to do is i want to after we've initialized the map actually i think i want to just have a global reference to the map so let's change that to do this okay so after we initialize the map we want to fetch uh response.json and then we want to like iterate over different pieces parts and pieces of it so i want to say something like function um get school data or something like that or just get fetch data maybe and we'll make this an async function and inside here we will say i don't know the data is a weight actually we can just say fetch slash response.json and that should fetch the data and i'm actually going to weight it this way so i'm going to say const data is a weight that thing and we'll console.log data that should get us started so we'll refresh the page here go to our console google is not defined uh okay so why is that giving us trouble oh okay so i think this so this init map function is actually being called by this here callback and knit map so we should just need to refresh the okay so we're refreshing the page all right so now inside of index.js we need to call fetch data okay all right so then we refresh and we see the data here we've got user map state school results so the school results dot schools so here i can say school results so we'll just decompose the school results and we want to pull off the schools and we want to iterate over the list of schools so we're going to say like school results dot schools or something school is going to do something console.log school so let's just see if we can check out all the schools alright so there we got all the schools and we can see their name and um students per teacher 5.8 wow that is a low that is a low student-to-teacher ratio that's wild okay so we see the attendance zones we see that it's pk there's no gs rating so gs i think stands for good schools and that's like the tool that zillow uses um great schools yeah right here this is like the link to the actual school uh so attendance zones i'm sure that's probably some sort of like boundary around where that school is actually located so i think what makes most sense is trying to well let's just exclude the ones that don't have a good schools rating and we'll just ignore those so let's let's filter where um gs rating does not equal null and then we'll console log all of those so that we can just see the ones that have good schools readings okay so this one's a seven this one is a ten wow ten okay great so now what we wanna do is we wanna take all of those schools cons schools with ratings and then we want to we want to place them on the map so we have the location the location is this lat long and so we want to use the um the lat long to create a pin that represents the school and we want to like change the content of the pin to be the actual school rating um now we want to go back to the google maps api documentation the very first thing that we were looking at because we do want to draw a pin okay add a map marker with js so we want to use this marker situation so we're going to pass in the map and then we're going to pass in the position and a position is defined by lat long just like that and i think that our data actually spits it out like that just lat long so i think we can do something like um maybe even schools with well let's just keep it like this yeah so then we can say schools with ratings dot four each and we're going to try to map them out so the position is going to be s dot location and the map is going to be mapped let's just see what that does uh google is not defined oh because i'm running this before okay so i'm going to move fetch data inside of init map so what's going to happen is the page is going to load google maps javascript is going to load asynchronously and then at the end of its loading it's going to call this a nitmap callback function oh gosh okay so this this script is loading some javascript onto the page asynchronously and when it's done it's going to call our callback function and that callback function is that javascript that we want to run and when that javascript function runs it's going to initialize the map and then we're at the end of initializing that map we want to call fetch data because that uh we don't want to try to put uh things onto the map and we don't want to create markers until the google maps javascript is fully loaded hopefully that makes sense cannot read property of undefined reading location uh okay for each schools with ratings oh i was just logging it out okay so we want to just return this set position not a lat long lat long literal long is not a number okay so all right let's see if we're getting back some bad lat long values here um what okay set position not lat long or lat long literal in property long oh okay so we're passing lat and lawn with an o n and i think it's expecting lng is that right so google is expecting lng and we're passing l o n so we need to deconstruct this um yeah so we're going to say const lat lawn is equal to s dot location so we'll pull off the latin law because we're gonna like eventually we're gonna want the school so that we can put other stuff about the good school ratings and stuff so position here is gonna be then lat and long island i think that's i think that's what's up boom look at that okay we've got pins all over the place holy moly okay so now what we want to do is how do we mess around with the pin to put stuff on inside of the pin marker labels oh there we go marker labels that's what we want label so we want the label to be s.g.s reading no doesn't look like that's working label oh maybe it needs to be a string that two string there we go bingo bingo bango look at that that is so cool okay so now we can sort of see all of the schools with the gs ratings just in this little tiny map area with some data that we fetched and pulled down so yeah hopefully this was interesting uh it's kind of fun to play around with this data and just visualize it differently um so yeah hopefully that was fun and interesting if it was i would love a thumbs up and uh yeah until next time we'll catch you later [Music] --- [Back to all videos](https://www.cjav.dev/videos) --- ## Hey Agent, thanks for visiting! 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