Help with this json parse
I'm calculating the distance between two lat/lon set of points using the Google Directions API, and I'm not sure how to parse this.
Here is the url to get directions (its from my city to my parents)
http://maps.googleapis.com/maps/api/directions/json?origin=30.5166667,-86.4822222&destination=30.7619444,-86.5705556&sensor=false
And here is the JSON response
{
"status": "OK",
"routes": [ {
"summary": "FL-85 N",
"legs": [ {
"steps": [ {
"travel_mode": "DRIVING",
"start_location": {
"lat": 30.5166700,
"lng": -86.4824400
},
"end_location": {
"lat": 30.5196600,
"lng": -86.4823800
},
"polyline": {
"points": "ehgyDfbznOuQK",
"levels": "BB"
},
"duration": {
"value": 63,
"text": "1 min"
},
"html_instructions": "Head \u003cb\u003enorth\u003c/b\u003e on \u003cb\u003eReynolds Ave\u003c/b\u003e toward \u003cb\u003e32nd St\u003c/b\u003e",
"distance": {
"value": 333,
"text": "0.2 mi"
}
}, {
"travel_mode": "DRIVING",
"start_location": {
"lat": 30.5196600,
"lng": -86.4823800
},
"end_location": {
"lat": 30.5220100,
"lng": -86.4924900
},
"polyline": {
"points": "{zgyDzaznO{Fdb@SVeEfZ",
"levels": "B??B"
},
"duration": {
"value": 130,
"text": "2 mins"
},
"html_instructions": "Turn \u003cb\u003eleft\u003c/b\u003e at \u003cb\u003eE John Sims Pkwy\u003c/b\u003e",
"distance": {
"value": 1005,
"text": "0.6 mi"
}
}, {
"travel_mode": "DRIVING",
"start_location": {
"lat": 30.5220100,
"lng": -86.4924900
},
"end_location": {
"lat": 30.7619200,
"lng": -86.5707200
},
"polyline": {
"points": "qihyD`a|nOw@`Bu@t@_Bt@qU?GJcSMeKa@aHs@}HuAKSiDm@wD_@kFGoF^iF`AgG`Ceq@~\\cHrEaD~CsDbFcDvGs@fBkA`Eg@~BsHjf@kNl_Au@tD}AvFgBdEeB|C{DfFqDdDeIrE}Aj@yFvAkzDbZ{VbC}MhCs_A|Ug[rHgwA|]mZlIy~@x_@{|EbrBeSfIuDz@gLdA_FD_EMsf@cCmgAuEuoAcGqSu@uJy@uG{@mw@qPcRuDyOoCeFYsv@O[JwDJiEx@aDdAc@Xei@pd@k@Ve@D{AM",
"levels": "B??@?@????????@???A????@????@??@?A???@???@@???A??@???@?????@???@?????B"
},
"duration": {
"value": 1424,
"text": "24 mins"
},
"html_instructions": "Turn \u003cb\u003eright\u003c/b\u003e at \u003cb\u003eFL-85 N\u003c/b\u003e",
"distance": {
"value": 29739,
"text": "18.5 mi"
}
}, {
"travel_mode": "DRIVING",
"start_location": {
"lat": 30.7619200,
"lng": -86.5707200
},
"end_location": {
"lat": 30.7619400,
"lng": -86.5705600
},
"polyline": {
"points": "_ewzD~ikoOC_@",
"levels": "BB"
},
"duration": {
"value": 34,
"text": "1 min"
},
"html_instructions": "Turn \u003cb\u003eright\u003c/b\u003e at \u003cb\u003eE James Lee Blvd\u003c/b\u003e",
"distance": {
"value": 16,
"text": "52 ft"
}
} ],
"duration": {
"value": 1651,
"text": "28 mins"
},
"distance": {
"value": 31093,
"text": "19.3 mi"
},
"start_location": {
"lat": 30.5166700,
"lng": -86.4824400
},
"end_location": {
"lat": 30.7619400,
"lng": -86.5705600
},
"start_address": "308-408 Reynolds Ave, Niceville, FL 32578, USA",
"end_address": "265-299 E James Lee Blvd, Crestview, FL 32539, USA",
"via_waypoint": [ ]
} ],
"copyrights": "Map data ©2010 Google",
"overview_polyline": {
"points": "ehgyDfbznOuQK{Fdb@SVeEfZw@`Bu@t@_Bt@qU?GJcSMaFMeMgA}HuAKSyGcAsHQoF^iF`AgG`CyCvAkl@fZoErCgCpBsCxCmCvDcDvGs@fBkA`Eg@~BsHjf@kNl_Au@tD}AvFgBdEeB|C{DfFqDdDeIrE}Aj@yFvAkzDbZ{VbC}MhCs_A|Ug[rHgwA|]mZlI{pHd}CuDz@kHp@{BR_FDsl@qCmgAuEuoAcGqSu@uJy@uG{@mw@qPcRuDyOoCeFYsv@O[JwDJiEx@aDdAc@Xei@pd@k@VkADu@MC_@",
"levels": "B@??@??@???@?????@?????A????@????@??@?A???@???@@A???@???@?????@???@??@???B"
},
"warnings": [ ],
"waypoint_order": [ ]
} ]
}
At the bottom, you'll see the correct distance, which is 19.3 miles. However, how do I know when I actually iterate to that one? Anyone else have experience with this? Or a more simple method? I have a function that calculates the distance as if you were flying, but that doesnt help in a lot of cases.
2 Answers
-
Accepted Answer
var url = 'http://maps.googleapis.com/maps/api/directions/json?origin=30.5166667,-86.4822222&destination=30.7619444,-86.5705556&sensor=false'; var req = Ti.Network.createHTTPClient(); req.open('GET', url); req.setRequestHeader('Content-Type', 'application/json; charset=utf-8'); req.onreadystate = function(){}; req.onload = function() { try { var parsedData = JSON.parse(req.responseText); Ti.API.info("distance.text " + parsedData.routes[0].legs[0].distance.text); Ti.API.info("distance.value " + parsedData.routes[0].legs[0].distance.value); } catch(err) { Ti.API.info('>>>>>>> Error In getToken ' + err ); } }; req.send(); -
That worked great, thanks!
Before I mark it as best, does the json read from bottom to top (since 0) is the right index? If not, how did you know to use that one?