If Apex Call Out I use 'I call you' metaphor to represent Salesforce need to contact external service, therefore we need external service info such as - url and set end point url in Remote Site Setting.
While Apex Web Service I use 'You call me' which mean we need to expose our Apex class either as SOAP or REST for external service to connect.
 |
| You call me! In order for them to you, you need to give your phone number |
Expose a class as REST Service
- Define class with global access modifier .
- Use @RestResource annotation at class level to enable it serve as webservice
- Example : @RestResource(urlMapping='/Case/*')
- Define method with global static .
- Add an annotation to associate with Http method. Bear in mind on one method is allowed per class. It means there should be only one GET method per class.
- Endpoint URL that we need to share to external service will look like this: https://yourInstance.salesforce.com/services/apexrest/Case/*
| Annotation | Action | Details |
|---|---|---|
| @HttpGet | Read | Reads or retrieves records. |
| @HttpPost | Create | Creates records. |
| @HttpDelete | Delete | Deletes records. |
| @HttpPut | Upsert | Typically used to update existing records or create records. |
| @HttpPatch | Update | Typically used to update fields in existing records. |
Example
@RestResource(urlMapping='Cases/*') global with sharing class MyRestResource { @HttpGet global static Case getRecord() { // Add your code } }
Expose a class as SOAP Service
- Define class with global access modifier .
- Define your method with 'webservice static'
- You need to generate WSDL and send it to the external developer so they can write integration to connect wit us.
Example
References :
Awesome Trailhead Apex Web Services
Still standing : Apex Web Services and Callouts
global class Project { webservice String area; webservice String region; //Define an object in apex that is exposed in apex web service global class Plan { webservice String name; webservice Integer planNumber; webservice Date planningPeriod; webservice Id planId; } webservice static Plan createProjectPlan(Plan vPlan) { //A plan maps to the Project__c object in salesforce.com. //So need to map the Plan class object to Project__c standard object Project__c proj = new Project__c(); proj.Name = vPlan.name; proj.AccountNumber = String.valueOf(vPlan.planNumber); insert proj; vPlan.planId=proj.Id; return vPlan; }
Conclusion
This entry explains on custom Apex code for REST and SOAP API and it not the only way for external applications to connect with Salesforce. There a few ways to connect such as using Salesforce's REST and SOAP APIs. It has different strengths to fulfill business requirement.References :
Awesome Trailhead Apex Web Services
Still standing : Apex Web Services and Callouts
