Integrating Salesforce with external APIs allows organizations to seamlessly connect with third-party systems, enhancing productivity and enabling advanced workflows. In this guide, we’ll explore a practical example of integrating Salesforce with an external REST API using Apex.

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What Is Salesforce API Integration?

Salesforce API integration connects Salesforce with external systems for:

• Data synchronization between platforms.
• Triggering external services based on Salesforce actions.
• Automating workflows involving third-party systems.

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Integration Use Case

Objective

We’ll create an integration to fetch weather data from a public API (e.g., OpenWeatherMap) and display it on a custom Salesforce record page.

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Step-by-Step Implementation

Step 1: Set Up API Access

1. Register for API Access:
   • Sign up at OpenWeatherMap or another public API provider.
   • Obtain an API key for authentication.
2. API Endpoint Example:
   • URL: https://api.openweathermap.org/data/2.5/weather?q=CityName&appid=YourAPIKey
   • Replace CityName with a dynamic city name and YourAPIKey with the API key.

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Step 2: Create an Apex Class for API Callout

1. Define the Apex Class:
   • Go to Setup → Apex Classes → New.
   • Replace Custom_Object__c and Weather_Temperature__c with your custom object and field names.

Write the Callout Code:

public with sharing class WeatherAPIService {
    @future(callout=true)
    public static void fetchWeatherData(String cityName, Id recordId) {
        try {
            // API endpoint
            String endpoint = 'https://api.openweathermap.org/data/2.5/weather?q=' + cityName + '&appid=YourAPIKey';
            Http http = new Http();
            HttpRequest request = new HttpRequest();
            request.setEndpoint(endpoint);
            request.setMethod('GET');

            // Make the callout
            HttpResponse response = http.send(request);

            if (response.getStatusCode() == 200) {
                // Parse the JSON response
                Map<String, Object> responseBody = (Map<String, Object>) JSON.deserializeUntyped(response.getBody());
                Map<String, Object> mainData = (Map<String, Object>) responseBody.get('main');
                Decimal temperature = (Decimal) mainData.get('temp');

                // Update Salesforce record
                Custom_Object__c recordToUpdate = [SELECT Id, Weather_Temperature__c FROM Custom_Object__c WHERE Id = :recordId];
                recordToUpdate.Weather_Temperature__c = temperature;
                update recordToUpdate;
            } else {
                System.debug('Error in API call: ' + response.getStatus());
            }
        } catch (Exception e) {
            System.debug('Exception during API call: ' + e.getMessage());
        }
    }
}

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Step 3: Add a Button to Trigger the Integration

1. Navigate to Object Manager:
   • Go to Setup → Object Manager → Select your custom object.
2. Create a Button:
   • Go to Buttons, Links, and Actions → New Button or Link.
   • Label: Fetch Weather.
   • Display Type: Detail Page Button.
   • Behavior: Execute JavaScript.
3. Add the Button to Page Layout:
   • Go to Page Layouts → Drag the button to the layout.

Code:

{!REQUIRESCRIPT("/soap/ajax/48.0/connection.js")}
{!REQUIRESCRIPT("/soap/ajax/48.0/apex.js")}

sforce.apex.execute("WeatherAPIService", "fetchWeatherData", {
    cityName: "{!Custom_Object__c.City__c}",
    recordId: "{!Custom_Object__c.Id}"
});

alert("Weather data is being fetched.");

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Step 4: Test the Integration

1. Create a Test Record:
   • Add a record in your custom object with a valid city name in the City__c field.
2. Click the Button:
   • Open the record and click the Fetch Weather button.
3. Verify the Data:
   • Check the updated Weather_Temperature__c field for the fetched temperature.

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Step 5: Handle Security and API Limits

1. Add Remote Site Settings:
   • Go to Setup → Remote Site Settings → New Remote Site.
   • Add the API domain (e.g., https://api.openweathermap.org).
2. Consider API Limits:
   • Monitor API limits and configure the integration to handle retries or fallback gracefully.

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Best Practices for Salesforce API Integration

1. Secure API Keys:
   • Store API keys in Salesforce Custom Settings or Custom Metadata for better security.
2. Handle Errors Gracefully:
   • Use robust error handling and log errors for debugging.
3. Test in Sandbox:
   • Always test integrations in a Salesforce sandbox environment before deploying to production.
4. Optimize Callouts:
   • Minimize API callouts by caching responses or using batch processing.

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Conclusion

Integrating Salesforce with external APIs enables powerful workflows and data synchronization. This guide demonstrated how to fetch weather data from an external API and update a Salesforce record. By following these steps and best practices, you can build seamless integrations tailored to your business needs, enhancing the value of your Salesforce platform.