I am currently trying to output to the user the probability of precipitation (POP) in their given city using the Wunderground API and PHP. The Wunderground API returns its requests in JSON format. Yet I am currently getting nothing back and I don't know what the problem is.
Below is my code:
<?php
$json_string = file_get_contents("http://api.wunderground.com/api/API_KEY/forecast/q/IA/Cedar_Rapids.json");
$parsed_json = json_decode($json_string);
$location = $parsed_json->{'forecast'}->{'txt_forecast'}->{'forecastday'};
$pop = $parsed_json->{'pop'};
echo "Percipation: ${pop}%";
?>
I know that this task is accomplishable with Javascript, I eventually want it to interface to a MySQL database.
*** I didn't include my API Key because I have a limited number of API calls per day, and after that I start getting charged money :(.
EDIT 1:
Below is the HTTP Response Header
array(13) {
[0]=> string(15) "HTTP/1.0 200 OK"
[1]=> string(20) "Accept-Ranges: bytes"
[2]=> string(29) "Cache-Control: max-age=604800"
[3]=> string(23) "Content-Type: text/html"
[4]=> string(35) "Date: Mon, 20 Feb 2017 20:55:54 GMT"
[5]=> string(17) "Etag: "359670651""
[6]=> string(38) "Expires: Mon, 27 Feb 2017 20:55:54 GMT"
[7]=> string(44) "Last-Modified: Fri, 09 Aug 2013 23:54:35 GMT"
[8]=> string(22) "Server: ECS (cpm/F9D5)"
[9]=> string(21) "Vary: Accept-Encoding"
[10]=> string(12) "X-Cache: HIT"
[11]=> string(20) "Content-Length: 1270"
[12]=> string(17) "Connection: close"
}
EDIT 2:
Below is the JSON return (Brace yourself)
{
"response": {
"version":"0.1",
"termsofService":"http://www.wunderground.com/weather/api/d/terms.html",
"features": {
"forecast": 1
}
}
,
"forecast":{
"txt_forecast": {
"date":"1:04 PM CST",
"forecastday": [
{
"period":0,
"icon":"rain",
"icon_url":"http://icons.wxug.com/i/c/k/rain.gif",
"title":"Monday",
"fcttext":"Cloudy with periods of rain. Thunder possible. High 61F. Winds S at 10 to 15 mph. Chance of rain 90%.",
"fcttext_metric":"Rain. Thunder possible. High 16C. Winds S at 15 to 25 km/h. Chance of rain 90%.",
"pop":"90"
}
,
{
"period":1,
"icon":"nt_chancerain",
"icon_url":"http://icons.wxug.com/i/c/k/nt_chancerain.gif",
"title":"Monday Night",
"fcttext":"Rain showers this evening with overcast skies overnight. Thunder possible. Low 39F. Winds W at 5 to 10 mph. Chance of rain 60%.",
"fcttext_metric":"Showers early, then cloudy overnight. Thunder possible. Low 4C. Winds WSW at 10 to 15 km/h. Chance of rain 60%.",
"pop":"60"
}
,
{
"period":2,
"icon":"partlycloudy",
"icon_url":"http://icons.wxug.com/i/c/k/partlycloudy.gif",
"title":"Tuesday",
"fcttext":"Some clouds in the morning will give way to mainly sunny skies for the afternoon. Near record high temperatures. High around 65F. Winds WSW at 5 to 10 mph.",
"fcttext_metric":"Some clouds in the morning will give way to mainly sunny skies for the afternoon. Near record high temperatures. High 18C. Winds WSW at 10 to 15 km/h.",
"pop":"10"
}
,
{
"period":3,
"icon":"nt_clear",
"icon_url":"http://icons.wxug.com/i/c/k/nt_clear.gif",
"title":"Tuesday Night",
"fcttext":"Clear skies. Low 39F. Winds SSW at 5 to 10 mph.",
"fcttext_metric":"Clear skies. Low 4C. Winds SSW at 10 to 15 km/h.",
"pop":"10"
}
,
{
"period":4,
"icon":"partlycloudy",
"icon_url":"http://icons.wxug.com/i/c/k/partlycloudy.gif",
"title":"Wednesday",
"fcttext":"Mostly sunny skies with gusty winds developing during the afternoon. High 71F. Winds SSW at 20 to 30 mph.",
"fcttext_metric":"Mostly sunny skies. Becoming windy during the afternoon. High 21C. Winds SSW at 30 to 50 km/h.",
"pop":"10"
}
,
{
"period":5,
"icon":"nt_clear",
"icon_url":"http://icons.wxug.com/i/c/k/nt_clear.gif",
"title":"Wednesday Night",
"fcttext":"A mostly clear sky. Low 38F. Winds WNW at 5 to 10 mph.",
"fcttext_metric":"A mostly clear sky. Low 3C. Winds WNW at 10 to 15 km/h.",
"pop":"10"
}
,
{
"period":6,
"icon":"chancerain",
"icon_url":"http://icons.wxug.com/i/c/k/chancerain.gif",
"title":"Thursday",
"fcttext":"Partly cloudy in the morning. Increasing clouds with periods of showers later in the day. High 54F. Winds NE at 15 to 25 mph. Chance of rain 80%.",
"fcttext_metric":"Partly cloudy skies during the morning hours will give way to occasional showers in the afternoon. High 12C. Winds NE at 25 to 40 km/h. Chance of rain 90%.",
"pop":"80"
}
,
{
"period":7,
"icon":"nt_tstorms",
"icon_url":"http://icons.wxug.com/i/c/k/nt_tstorms.gif",
"title":"Thursday Night",
"fcttext":"Showers along with a few thunderstorms. Low 39F. Winds ENE at 20 to 30 mph. Chance of rain 100%.",
"fcttext_metric":"Windy with showers and thunderstorms likely. Low 4C. Winds ENE at 30 to 50 km/h. Chance of rain 100%.",
"pop":"100"
}
]
},
"simpleforecast": {
"forecastday": [
{"date":{
"epoch":"1487638800",
"pretty":"7:00 PM CST on February 20, 2017",
"day":20,
"month":2,
"year":2017,
"yday":50,
"hour":19,
"min":"00",
"sec":0,
"isdst":"0",
"monthname":"February",
"monthname_short":"Feb",
"weekday_short":"Mon",
"weekday":"Monday",
"ampm":"PM",
"tz_short":"CST",
"tz_long":"America/Chicago"
},
"period":1,
"high": {
"fahrenheit":"61",
"celsius":"16"
},
"low": {
"fahrenheit":"39",
"celsius":"4"
},
"conditions":"Rain",
"icon":"rain",
"icon_url":"http://icons.wxug.com/i/c/k/rain.gif",
"skyicon":"",
"pop":90,
"qpf_allday": {
"in": 0.28,
"mm": 7
},
"qpf_day": {
"in": 0.27,
"mm": 7
},
"qpf_night": {
"in": 0.08,
"mm": 2
},
"snow_allday": {
"in": 0.0,
"cm": 0.0
},
"snow_day": {
"in": 0.0,
"cm": 0.0
},
"snow_night": {
"in": 0.0,
"cm": 0.0
},
"maxwind": {
"mph": 15,
"kph": 24,
"dir": "S",
"degrees": 169
},
"avewind": {
"mph": 12,
"kph": 19,
"dir": "S",
"degrees": 169
},
"avehumidity": 84,
"maxhumidity": 0,
"minhumidity": 0
}
,
{"date":{
"epoch":"1487725200",
"pretty":"7:00 PM CST on February 21, 2017",
"day":21,
"month":2,
"year":2017,
"yday":51,
"hour":19,
"min":"00",
"sec":0,
"isdst":"0",
"monthname":"February",
"monthname_short":"Feb",
"weekday_short":"Tue",
"weekday":"Tuesday",
"ampm":"PM",
"tz_short":"CST",
"tz_long":"America/Chicago"
},
"period":2,
"high": {
"fahrenheit":"65",
"celsius":"18"
},
"low": {
"fahrenheit":"39",
"celsius":"4"
},
"conditions":"Partly Cloudy",
"icon":"partlycloudy",
"icon_url":"http://icons.wxug.com/i/c/k/partlycloudy.gif",
"skyicon":"",
"pop":10,
"qpf_allday": {
"in": 0.00,
"mm": 0
},
"qpf_day": {
"in": 0.00,
"mm": 0
},
"qpf_night": {
"in": 0.00,
"mm": 0
},
"snow_allday": {
"in": 0.0,
"cm": 0.0
},
"snow_day": {
"in": 0.0,
"cm": 0.0
},
"snow_night": {
"in": 0.0,
"cm": 0.0
},
"maxwind": {
"mph": 10,
"kph": 16,
"dir": "WSW",
"degrees": 238
},
"avewind": {
"mph": 9,
"kph": 14,
"dir": "WSW",
"degrees": 238
},
"avehumidity": 63,
"maxhumidity": 0,
"minhumidity": 0
}
,
{"date":{
"epoch":"1487811600",
"pretty":"7:00 PM CST on February 22, 2017",
"day":22,
"month":2,
"year":2017,
"yday":52,
"hour":19,
"min":"00",
"sec":0,
"isdst":"0",
"monthname":"February",
"monthname_short":"Feb",
"weekday_short":"Wed",
"weekday":"Wednesday",
"ampm":"PM",
"tz_short":"CST",
"tz_long":"America/Chicago"
},
"period":3,
"high": {
"fahrenheit":"71",
"celsius":"22"
},
"low": {
"fahrenheit":"38",
"celsius":"3"
},
"conditions":"Partly Cloudy",
"icon":"partlycloudy",
"icon_url":"http://icons.wxug.com/i/c/k/partlycloudy.gif",
"skyicon":"",
"pop":10,
"qpf_allday": {
"in": 0.00,
"mm": 0
},
"qpf_day": {
"in": 0.00,
"mm": 0
},
"qpf_night": {
"in": 0.00,
"mm": 0
},
"snow_allday": {
"in": 0.0,
"cm": 0.0
},
"snow_day": {
"in": 0.0,
"cm": 0.0
},
"snow_night": {
"in": 0.0,
"cm": 0.0
},
"maxwind": {
"mph": 30,
"kph": 48,
"dir": "SSW",
"degrees": 202
},
"avewind": {
"mph": 21,
"kph": 34,
"dir": "SSW",
"degrees": 202
},
"avehumidity": 57,
"maxhumidity": 0,
"minhumidity": 0
}
,
{"date":{
"epoch":"1487898000",
"pretty":"7:00 PM CST on February 23, 2017",
"day":23,
"month":2,
"year":2017,
"yday":53,
"hour":19,
"min":"00",
"sec":0,
"isdst":"0",
"monthname":"February",
"monthname_short":"Feb",
"weekday_short":"Thu",
"weekday":"Thursday",
"ampm":"PM",
"tz_short":"CST",
"tz_long":"America/Chicago"
},
"period":4,
"high": {
"fahrenheit":"54",
"celsius":"12"
},
"low": {
"fahrenheit":"39",
"celsius":"4"
},
"conditions":"Chance of Rain",
"icon":"chancerain",
"icon_url":"http://icons.wxug.com/i/c/k/chancerain.gif",
"skyicon":"",
"pop":80,
"qpf_allday": {
"in": 0.70,
"mm": 18
},
"qpf_day": {
"in": 0.07,
"mm": 2
},
"qpf_night": {
"in": 0.64,
"mm": 16
},
"snow_allday": {
"in": 0.0,
"cm": 0.0
},
"snow_day": {
"in": 0.0,
"cm": 0.0
},
"snow_night": {
"in": 0.0,
"cm": 0.0
},
"maxwind": {
"mph": 25,
"kph": 40,
"dir": "NE",
"degrees": 42
},
"avewind": {
"mph": 19,
"kph": 31,
"dir": "NE",
"degrees": 42
},
"avehumidity": 72,
"maxhumidity": 0,
"minhumidity": 0
}
]
}
}
}
I think you are using the wrong variable in
$pop = $parsed_json->{'pop'};
Try it with
$pop = $location[0]->{'pop'};
Be aware that $location should be an array, so trying to directly access it ($location->{'pop'}) will not work. The 0 index serves only as an example.