Hi. I am building two apps. One is for the customer to use and the other is for the taxi driver. I use the location sensor in the customer app to get his latitude and longitude and send this off to Google geocoding to get an address a driver will recognise. The customer then inputs his destination and I send this off to google again. I use google distance matrix to get the distance between two the two points and calculate a cost based on that. The driver is alerted to a new job being available when the customer submits it to the firebase RT Database. I use a listener for this.
I am a long way off finishing this but I can give you more detail on how I have done what I have done so far if you let me know what you need.
Hi again. Having trouble with looping through the list still. Is j just a random variable name used for counting or does it need to refer to an item in the list? Do I need to call the variable “steps” or something in the list? I have these blocks and they are crashing the app. If I remove the “for each item” loop the code works correctly and returns some details from the list.
You use the j variable from the Variables drawer since that’s the loop index variable. Instead of a 1 where you have a list item, you use j in its place.
I’m on my phone so I can’t show you blocks right now but can post some later.
I’m not all that familiar with Google Directions but it seems like the API is returning a JSON response that formats the “steps” (within a “leg” within a “route”) as, in order:
So if we get the first start_location and end_location, we’ll know where to send your drivers. But… if we then get the next pair, we have duplicate data points because the end_location for the first step is the start_location for the second step. We really only need the first start_location and then every end_location after that.
That of course depends on how you plan to display steps data to the user/driver. Maybe you want it to show “go from lat/lng A to lat/lng B” then “go from lat/lng B to lat/lng C”… OR maybe you want it to show “go from lat/lng A to lat/lng B” then “go to lat/lgn C”.
I thought I had a handle on this and started making a demo for the latter option but it’s not working for me. Something to do with object vs. list handling.
Thanks for looking at this for me. I think I am going for one start location and then every end location after that. I think thats all I need to draw the polyline. Your blocks have given me some ideas which I will work on this week. I’ll let you know how I get on
Am I doing something wrong with the loop or placing the j in the wrong place.
I noted in your approach you created a list of the legs and steps and used the for each loop on that. Did that work and why doesnt my approach? Any ideas on where I am going wrong would be appreciated.
The issue is that you have the “j” variable in the right place as a list index for the “steps” property. But you are declaring j as an item in list “app JsonDirectionsText” and my guess is that you’re still returning the entire JSON response as a value for “app JsonDirectionsText.” That’s not going to work. You want the “in list [ ]” variable to be declared as everything inside of the the “in list [ ] get #j block.” That’s what I was trying to do with my example above but I got stuck somewhere.
Its not the most elegant solution but this does seem to work. I am using the count with i function as I know the number of steps in each leg of the route. Hopefully it will be easy to create a list from the text string I am building. I’ll mark this as solved but I am sure I will be back later.
HI again. Trust you are keeping well in these difficult times. I’ve been making good progress on my taxi app but seem to be stuck on something very simple. I want to get the duration of the first leg of the journey. Looking at the returned JSON file the following should get me what I need.
There is only one route so #1 for that. I want the first leg so #1 for that as well. Then duration then text. But this does not appear to return a value at all and I end up with a blank space in my message where the duration like “1 min” should be. Am I missing something here? I have attached a recent response file in case it helps.geocodedJSON.txt (7.3 KB)
Is your API “Get” call returning an error (green error block)?
Are you doing anything else with the DurationStep1 variable after this that might affect its value? What happens if you replace the “set app variable DurationStep1” block with a “from Label1 set Text to” block?
Are you initializing the DurationStep1 variable as blank (no connected block) or as a particular type (text string, list, etc.)?
I do a lot with the information return in the request and everything else works fine so I don’t believe I am getting an error. Here is a small sample from the main app.
Officially weird! I initialised the Step1Duration value to ABC and thats the value I show when I print the variable value. However when I copy the value to a label I get a value of 1 min.
Hi, I am building this on my own. Not sure about sharing it when its done as I am developing it for a customer. When I am done, it will be his property. But I can ask him.
