Does Google MAP API Use Async Request - javascript

I wrote a small app to test out Google Map API and I noticed that my functions do not execcute in the expected order. Please take a look at my code below.
<!DOCTYPE html><htm><head><title></title>
<script src="http://maps.google.com/maps/api/js?sensor=false"></script>
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"> </script>
<script>
//Global Variables
var lat, lng, _Address;
var geocoder = new google.maps.Geocoder();
function getReverseGeocodingData(lat, lng) {
var latlng = new google.maps.LatLng(lat, lng);
// Make the Geocode request
geocoder.geocode({ 'latLng': latlng }, function (searchResults,searchStatus) {
if (searchStatus !== google.maps.GeocoderStatus.OK) {
alert("Your search yields " + searchStatus);
}
// Checking to see if the Geocode Status is OK before proceeding
if (searchStatus == google.maps.GeocoderStatus.OK) {
console.log(searchResults);
_Address = (searchResults[0].formatted_address);
alert("First time Address is displayed" + _Address);
}
});
}
function splitAddress() {
var addressArr = _Address.split(',');
//addressArr will be used later
}
// This function is called when the submit button is clicked
function SearchAddress() {
geocoder.geocode({ 'address': "77 Massachusetts Ave, Cambridge, MA 02139" }, function (searchResults, searchStatus) {
var location = searchResults[0].geometry.location;
lat = location.lat();
lng = location.lng();
getReverseGeocodingData(lat, lng);
alert("Second time Address is displayed" + _Address);
splitAddress();
});}
</script></head><body><div><input type="button" value="Submit" onclick="SearchAddress()"></div></body></html>
When I set a break point on the line alert("First time Address is displayed" + _Address), I can tell that this alert function executes before the line alert("Second time Address is displayed" + _Address).
However, the line alert("Second time Address is displayed" + _Address) appears as though it executes first and the value of _Address is undefined. So my question is if the second alert function executes after the first alert function, is Google Map API making an asynchronous request.

Yes, Google Maps API uses asynchronous requests when you call geocoder.geocode.
This is in the documentation.
Accessing the Geocoding service is asynchronous, since the Google Maps
API needs to make a call to an external server.

Related

Input location with Yahoo's weather API using simpleWeather.js?

I'm building a web-page that shows the weather. I would like for it to be able to use geolocation, as well as the option to manually input a location to pull weather information. I've got the geolocation working fine, but am unsure as to how to add an additional input using either a city or zipcode.
Here's my relevant code:
if ("geolocation" in navigator) {
navigator.geolocation.getCurrentPosition(function(position) {
loadWeather(position.coords.latitude + ',' + position.coords.longitude);
});
} else {
loadWeather("", "1062617");
}
function loadWeather(location, woeid) {
$.simpleWeather({
location: location,
woeid: woeid,
unit: 'f',
success: function(weather) {
$(".weather-text").html(weatherText[weather.code]);
$(".weather-icon").html('<i class="icon-' + weather.code + '"></i>');
$(".weather-stats").html('<ul><li><strong>'+weather.city+', ' +weather.region+ '</strong></li>');
$(".weather-stats").append('<li>'+ weather.temp + '°F / '+ weather.alt.temp +'°C</li></ul>');
},
error: function(error) {
$("#weather").html('<p>' + error + '</p>');
}
});
}
I'm pretty new to javascript & jquery, so I understand how to make an input box with HTML but am unsure how to use the user input data to then retrieve the associated weather data.
The getCurrentPosition gives you access to the position interface which then gives you the coordinates. So your if statement results in a latitude and longitude based on the device's Geolocation. In order to get this same information from a user's input (latitude and longitude), you need to convert the input (could be City, State or a full address) to coordinates. I recommend using Google maps API to convert that user input.
Once converted, you can then pass the lat and long to loadWeather(). Here's an example of a user's input (Address) converted:
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
<script type="text/javascript">
var geocoder = new google.maps.Geocoder();
var address = jQuery('#address').val();
geocoder.geocode( { 'address': address}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
var latitude = results[0].geometry.location.lat();
var longitude = results[0].geometry.location.lng();
jQuery('#coordinates').val(latitude+', '+longitude);
loadWeather(latitude + ',' + longitude);
}
});
</script>
<input id="address" type="text" placeholder="Enter City, State"/>
Of course you would use the above within proper context such as checking whether geolocation worked first or whenever a user actually enters their address. You might need a Google Maps API for this bit that should be easy to get.
Give it a shot, if stuck, check out this fiddle: jsfiddle
EDIT:
I grabbed Yahoo's Weather API endpoint and here is working fiddle:
https://jsfiddle.net/mjsgwq55/3/
I highly recommend logging variables so you can tell what time of data they contain. In your fiddle, you tried to access a property that doesn't exist in the object. Logging that would easily show you what to use.

Reverse Geocoding in Javascript returns MissingKeyMap error

I am trying to get formatted address of customer who access my web page.
For that I wrote function to get lat long and then Reverse geocode it to formatted address.
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
<script>
function coordinates_to_address(lat, lng) {
var latlng = new google.maps.LatLng(lat, lng);
var geocoder= new google.maps.Geocoder();
geocoder.geocode({'latLng': latlng}, function(results, status) {
if(status == google.maps.GeocoderStatus.OK) {
if(results[0]) {
$('#address_current').text(results[0].formatted_address);
} else {
alert('No results found');
}
} else {
var error = {
'ZERO_RESULTS': 'No address'
}
// alert('Geocoder failed due to: ' + status);
$('#address_new').html('<span class="color-red">' + error[status] + '</span>');
}
});
}
navigator.geolocation.getCurrentPosition(function(location) {
console.log(location.coords.latitude);
console.log(location.coords.longitude);
console.log(location.coords.accuracy);
var lat= location.coords.latitude;
var long= location.coords.longitude
coordinates_to_address(lat, long);
});
</script>
The log showed the output lat long
10.8888888888888888
76.43923530000001
40
But this function returned an error:
Google Maps API error: MissingKeyMapError https://developers.google.com/maps/documentation/javascript/error-messages#missing-key-map-error
http://maps.google.com/maps/api/js?sensor=false
Line 34
Is there any easier method to get the formatted address of a lat long?
Keys are now required with the Google Maps Javascript API v3 (but the sensor parameter is not).

How to use asynchronous Javascript?

I am using Google maps to get address in mobile application. Code is working fine when there is an internet connection. If not then my app takes 1 minute to load or sometimes it shows an application error. This is due to loading a URL within the script, so I wanted to load my script asynchronously. Can anyone give me some logic to solve my issue, how do I rewrite the below script asynchronously?
<script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?sensor=true">
function address()
{
var geocoder ;
geocoder = new google.maps.Geocoder();
var latlng = new google.maps.LatLng(latitude, longitude);
geocoder.geocode({'latLng': latlng}, function(results, status)
{
if (status == google.maps.GeocoderStatus.OK)
{
if (results[0])
{
var add= results[0].formatted_address ;
document.getElementById("location").innerHTML="Location : " + add ;
}
else
{
document.getElementById("location").innerHTML="No Results found " ;
}
}
else
{
//document.getElementById("location").innerHTML="Geocoder failed due to: " + status;
//alert("Geocoder failed due to: " + status);
}
});
}
This should do it:
jQuery.getScript('https://maps.googleapis.com/maps/api/js?sensor=true', address);
BTW, getScript() is a helper function for jQuery.ajax(). if you use the latter you can take more control and set more options, specifically a timeout parameter so it does not just spin for ever or the cache parameter so that you don't have to look it up all the time
A fiddle that's similar. Sorry fiddles can't use external resources directly so I have to create a simpler script request but you can see the callback is referencing the new javascript.

Javascript Function - Convert Geolocation Code to Street Address

I am looking for a javascript function or jquery library to convert geolocation code (e.g. 42.2342,32.23452) to street address
For examples.
navigator.geolocation.getCurrentPosition(
function(pos) {
$("#lat_field").val(pos.coords.latitude);
$("#long_field").val(pos.coords.longitude);
}
);
Here is a google api URL to get address data
http://maps.googleapis.com/maps/api/geocode/json?latlng=41.03531125,29.0124264&sensor=false
I want to see "formatted_address" : "Hacı Hesna Hatun Mh., Paşa Limanı Cd 2-26, 34674 Istanbul, Türkiye",
navigator.geolocation.getCurrentPosition(
function(pos) {
$("#lat_field").val(pos.coords.latitude);
$("#long_field").val(pos.coords.longitude);
$("#adress_data").getaddrfromlatlong(pos.coords.latitude,pos.coords.longitude)
}
);
This function should be how ?
``getaddrfromlatlong()
Try this:
<script src="http://maps.google.com/maps/api/js?sensor=false"></script>
<script type="text/javascript">
var geocoder = new google.maps.Geocoder();
var latLng = new google.maps.LatLng(41.03531125,29.0124264);
if (geocoder) {
geocoder.geocode({ 'latLng': latLng}, function (results, status) {
if (status == google.maps.GeocoderStatus.OK) {
console.log(results[0].formatted_address);
}
else {
console.log("Geocoding failed: " + status);
}
});
}
</script>
I haven't done it in Javascript but I did something similar using the google maps web service to download XML and parse the data out of it. They also have a JSON interface as well which is likely what you'd want to use. It really is rather trivial (download the data, then grep it) so I don't think you'll need a prewritten library for it.

Google Maps Geocoder not giving results

I am using jQuery with the Google Maps API V3's Geocoder. The site user enters a location in the textbox and clicks on the submit button, which calls the code below to geocode the address given by the user into LatLng coordinates.
$(function(){
$("#searchbox_form #search_button").click(function(){
var address = $("#location").val();
var geocoder = new google.maps.Geocoder();
alert(address);
geocoder.geocode( { 'address': address}, function(results, status) {
alert("123");
if (status == google.maps.GeocoderStatus.OK) {
$("#user_lat").val(results[0].geometry.location.lat);
$("#user_lng").val(results[0].geometry.location.lng);
alert("lat: " + $("#user_lat").val());
alert("lng: " + $("#user_lat").val());
} else {
alert("asdasdasd");
alert(status);
}
});
});
});
However there is some problem. You will notice I placed several alert()s in the code. When 'Boston' is entered into the textbox and the submit button is clicked, only alert("address"); is executed showing Boston but alert("123") does not run. Did something go wrong somewhere?
Solution is to disable the submitting of the form :)
Check in any web - debugger whether any request is even made or not?
The code seems fine to me.

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