Tag Archives: REST API

Invoking REST API From Visualforce Page

Usually we make Rest API calls from Salesforce to External systems to get the data or to pass the updates to External Systems, using Apex class. But sometimes we can have a situation, like where we need to make a call to external systems from the visual force page.

Salesforce has introduced a concept called AJAX ToolKit, which help us to make REST API call from the JavaScript in Visualforce Page. Here is an example to invoke REST API from Visualforce Page. In below example I’m using http://fixer.io/ web service HTTP callout and send a GET request to get the foreign exchange rates. The foreign exchange rates service sends the response in JSON format.

Visualforce Page:

<apex:page>
    <apex:includeScript value="//code.jquery.com/jquery-1.11.1.min.js" />
    <script>
    function apiCall() {
        //Get a reference to jQuery that we can work with
        $j = jQuery.noConflict();
        //endpoint URL
        var weblink = "https://api.fixer.io/latest?base=USD"; 
        
        $j.ajax({
            url: weblink,
            type: 'GET', //Type POST or GET
            dataType: 'json',
            beforeSend: function(request) {
                //Add all API Headers here if any
                //request.setRequestHeader('Type','Value');
            },
            
            crossDomain: true,
            //If Successfully executed 
            success: function(result) {
                //Response will be stored in result variable in the form of Object.
                console.log('Response Result' + result);
                
                //Convert JSResponse Object to JSON response
                var jsonResp = JSON.stringify(result);
                document.getElementById("apiData").innerHTML = jsonResp;
            },
            
            //If any Error occured
            error: function(jqXHR, textStatus, errorThrown) {
                //alert('ErrorThrown: ' + errorThrown);
            }
        });
    }
    </script>
    <apex:form>
        <!--call javaScript-->
        <input type="button" value="Call API" onclick="apiCall()" />
        <div id="apiData">
        </div>
    </apex:form>
</apex:page>

Read REST API GET Parameters in Apex Class

URL: /services/apexrest/AccountAPI?id=AccountId
Method: Get

@RestResource (urlMapping='/AccountAPI/*')
global with sharing class AccountRESTService {
    @HttpGet
    global static Account getAccount() {
        RestRequest req = RestContext.request;
        String accountId = req.params.get('id');
        Account acc = [SELECT Id, Name FROM Account WHERE Id =: accountId];
        return acc;
    }
}

URL: /services/apexrest/AccountAPI/AccountId
Method: Get

@RestResource (urlMapping='/AccountAPI/*')
global with sharing class AccountRESTService {

    @HttpGet
    global static Account getAccount() {
        RestRequest req = RestContext.request;
        String accountId = req.requestURI.substring(req.requestURI.lastIndexOf('/')+1);
        Account acc = [SELECT Id, Name FROM Account WHERE Id =: accountId];
        return acc;
    }
}

Difference Between Inbound and Outbound Web Service in Salesforce

Inbound Web Service:
Inbound web service is when Salesforce exposes SOAP/REST web service, and any external/third party application consume it to get data from your Salesforce org. It is an Inbound call to Salesforce, but outbound call to the external system. Here, Salesforce is the publisher and external system is the consumer of web services.

Outbound Web Service:
Outbound web service is when Salesforce exposes SOAP/REST web service, and any external/third party application consume it to get data from your Salesforce org. It is an Inbound call to Salesforce, but outbound call to the external system. Here, external system is the publisher of web services and Salesforce is the consumer.

There are two commonly used web service:

    • SOAP(Simple Object Access Protocol)
      • SOAP is a web service architecture, which specifies the basic rules to be considered while designing web service platforms.
      • It works over with HTTP, HTTPS, SMTP, XMPP.
      • It works with WSDL.
      • It is based on standard XML format.
      • SOAP Supports data in the form of XML only
      • SOAP API preferred for services within the enterprise in any language that supports Web services.
    • REST (Representational State Transfer)
      • REST is another architectural pattern, an alternative to SOAP.
      • It works over with HTTP and HTTPS.
      • It works with GET, POST, PUT and DELETE verbs to perform CRUD operations.
      • It is based on URI.
      • REST Supports both XML and JSON format.
      • REST API preferred for services that are exposed as public APIs and mobile, since JSON being Lighter the app runs smoother and faster.

Query Validation Rules associated with an Object using REST API

/services/data/v39.0/tooling/query?q=Select Id,ValidationName,Active,Description,EntityDefinition.DeveloperName,ErrorDisplayField, ErrorMessage From ValidationRule WHERE EntityDefinition.DeveloperName = 'Account'