Before writting long stories I would like to define the scope of the article and it's target audience. The last article was an overview of Integration using the two protocols and in this article I am gonna focus on an simple example how to create http callouts in Apex
The recipe requires
1. End point URL
2. Add the end poit URL in the remote site settings
3. Write an HTTP callout class
The end point URL iam gonna use here is Yahoo weather API one word condition for a city. In this case, I take Account's billing city and display the current contion of the billing city in a Inline visualforce page.
The Inline visualfoce page loads and send the record id to the controller , The controller selects the record and send the city information from the Account billing address to the Endpoint helper class fetch weather.
ont forget to add remote site settings in your org to make this work.
The code is below
Apex Class
public class fetchweather{
public string result = '';
public fetchweather(string city) {
Http http = new Http();
HttpRequest request = new HttpRequest();
string endpoint = 'https://query.yahooapis.com/v1/public/yql?q=';
String encodedURL = EncodingUtil.urlEncode('select item.condition.text from weather.forecast where woeid in (select woeid from geo.places(1) where text="'+city+'")', 'UTF-8');
string endpointurl = endpoint + encodedURL + '&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys' ;
System.debug(endpointurl+'++++');
request.setEndpoint(endpointurl );
request.setMethod('GET');
HttpResponse response = http.send(request);
System.debug(response.getBody());
JSONParser parser = JSON.createParser(response.getBody());
Map<String, Object> results = (Map<String, Object>)JSON.deserializeUntyped(response.getbody());
system.debug('results ::'+ results );
List<Object> lstforecast = (List<Object>)results.get('forecast');
system.debug('lstforecast ::'+ lstforecast );
while (parser.nextToken() != null) {
if ((parser.getCurrentToken() == JSONToken.FIELD_NAME) && (parser.getText() == 'text') ){
parser.nextToken();
result += 'The weather condition for '+ city+' is ' + parser.getText();
}
}
//result = response.getbody();
// return null;
}
}
VusualForce
==========
<apex:page standardController="Account" extensions="searchAccounts" showHeader="false" sidebar="false" >
<apex:form >
<apex:pageBlock >
<apex:pageBlockSection columns="1" >
</apex:pageBlockSection>
</apex:pageBlock>
<span id="theText" style="font-style:italic">{!result} </span>
</apex:form>
</apex:page>
Extension
==========
global class searchAccounts {
//Defining a standard controller
public ApexPages.StandardController controller {get; set;}
global string result {get;set;}
public Account a;
//Defining a standard controller
public searchAccounts(ApexPages.StandardController controller) {
this.controller = controller;
this.a = (Account)controller.getRecord();
system.debug('aaaaa'+a);
account acc = [select id,Account.BillingCity from account where id =:a.id];
fetchweather fw = new fetchweather(acc.BillingCity );
result = fw.result;
}
///////
}
