Salesforce - Call external API on button click and update custom field from response

Question

So I'll start by saying I'm a C# .Net/Javascript developer with a lot of experience, but I have zero experience with Salesforce. Never ever seen it before today. So, I've been asked by another team to add a custom button to a Contact object, which when clicked calls an external API and updates a custom field in the Contact with the response. It was pitched as "just write some Javascript that calls an API when a button is clicked, it's literally embedded into the page, 15 minute job...".

Following what appears to be quite an outdated document, I've ended up in the Object Manager, selected the Contact object and I'm into the Buttons, Links and Actions page. I'm assuming before this was done using the Execute Javascript behaviour, which in the Lightning version I'm advised against using. So after much Googling I've read about APEX classes, Visualforce Components, Lightning Components, the Salesforce REST API, etc, etc. Not a 15 min job.

Essentially the requirements are to embed a button (or action, or..?) into this Contact page, so that when the sales guy clicks it, it gathers some of the Contact's details and uses them to form an API call to an external service. The data will be used to form a response, which must then be read (as JSON, then parsed) and written into a custom field on the Contact.

What would be the best approach for developing a solution? In the Apex Debug environment I've put together the code to call the API and parse the JSON response, I'm assuming I need to wrap this in an Apex class, with a method that calls this code and returns the response. What I'm not sure of is how to call into this from the button, and update the field in the Contact. Do I need to do all that from the Apex Class method? passing in a reference to the Contact, or is there another component that needs to sit in between and do this. Am I right in assuming I'll need to use the Salesforce API to update the Contact?

Any pointers appreciated.

user_313628 · Answer

Oh man. It can be a 15 min job but it's definitely "easy when you know how" or have some examples ;)

What's your user interface, Classic or Lightning? Do they have plans to migrate to Lightning soon? I'm assuming it's Lightning if you figured out the "Execute JavaScript" hacks are passé.
Do you care where the button/action will be? Is the top right corner with all other buttons fine or do you want it to be droppable to pretty much any area in the page?
Does the API callout need username, password, maybe certificate? It'll determine whether you need just to whitelist the endpoint on firewall (Setup -> Remote Site Settings) or you'll need something more advanced (Setup -> Named Credentials).
Do you have SFDX command line (CLI), VSCode / are determined to install some tooling? The Lightning Web Components are cutting edge, most sleek etc but you can't create them straight in the browser (at least not yet), you need tooling. Visualforce is OK but nothing special for this use case, Aura components are bit clunky to write - but you can do both in Developer Console without extra tooling.
Parsing the JSON response - depends how complex it is, you can hand-craft parser with JSON.deserializeUntyped() but life's too short for this. Here's nice apex code generator similar to what you'd get from parsing WSDL: https://json2apex.herokuapp.com/

We'll try to do Aura component way. It's ugly, LWC is future but hey, it'll get you started.

Go to Setup -> Remote Site Settings and add new entry with https://en.wikipedia.org/

Create new Apex class:

public with sharing class Stack63364119 {
    static final String endpoint = 'https://en.wikipedia.org/w/api.php?action=query&format=json&list=search&srsearch=';
    @AuraEnabled
    public static String doCallout(Id contactId){
        if(contactId == null){
            throw new MyException('Missing record id');
        }
        List contacts = [SELECT MailingCountry FROM Contact WHERE Id = :contactId];
        if(contacts.isEmpty() || String.isBlank(contacts[0].MailingCountry)){
            throw new MyException('Could not find the contact');
        }
        Contact c = contacts[0];

        HttpRequest req = new HttpRequest();
        req.setEndpoint(endpoint + c.MailingCountry);
        req.setMethod('GET');

        HTTPResponse res = new Http().send(req);
        System.debug(res.getStatus());
        System.debug(res.getBody());
        // no special parsing, just chuck it into Description field
        // no error handling
        if(res.getStatusCode() == 200){
            c.Description = res.getBody().abbreviate(32000);
            update c;
        }
        return res.getBody();
    }
    public class MyException extends Exception{}
}

Make new "Lighning Component" in developer console (it'll be Aura, not LWC). You can tick the last checkbox about "lightning quick action". Name can be same as class but doesn't have to be.

For component (~ html part) paste this

For controller (~ JavaScript) paste this

({
    runCallout : function(cmp) {
        let action = cmp.get('c.doCallout');
        action.setParams({contactId : cmp.get('v.recordId')});
        action.setCallback(this, function(response){
            let state = response.getState();
            if (state === "SUCCESS") {
                alert('Saved OK: ' + response.getReturnValue());
                $A.get("e.force:closeQuickAction").fire(); // if you want to self-close
            } else if (state === "ERROR") {
                var errors = response.getError();
                if (errors) {
                    if (errors[0] && errors[0].message) {
                        console.log("Error message: " + errors[0].message);
                    }
                } else {
                    console.log("Unknown error");
                }
            }
        });
        $A.enqueueAction(action);
    }
})

Finally go Object Manager -> Contact -> Buttons Links and Actions. Create new Quick Action. And add it to page layout(s)!

It should get you started. Maybe you'll decide to split it a bit, Apex would only do the callout, return results to UI and if user is happy - updating the contact can be done with one of these: https://developer.salesforce.com/docs/atlas.en-us.lightning.meta/lightning/data_service_save_record.htm. Separation of concerns blah blah (but will the user be happy with 2 clicks).

P.S. If you tweak it and it dies but it's hard to see any JavaScript errors - it'll be because default is to run in release mode, SF rewrites your source code a bit, optimises, polyfills for "browsers" like IE11... Go to Setup -> Debug Mode and enable for your user.

P.P.S. In sandbox / dev org it's good idea to go Setup -> Session Settings -> and untick "Enable secure and persistent browser caching to improve performance". Your component will be always fresh, saves some frantic hitting Ctrl+R. Don't do it in prod ;)

user_7861605 · Answer

I will write to you my approach

Button on the record page/page layout -> lighting component or flow -> Apex class for collecting data -> apex class request & response API(don't forget to add the endpoint to remote site settings)-> parse response and update contact (you can use queries and DML operations inside Apex)

lighting component it will be very simple just have a the apex class as the controller example

controller

({
fetchContact : function(component, event, helper) {
    helper.fetchContactHelper(component, event, helper);
    
}
})

helper

({
fetchAccHelper : function(component, event, helper) {
    var action = component.get("c.fetchContacts");
    action.setParams({
    });
    action.setCallback(this, function(response){
        var state = response.getState();
        if (state === "SUCCESS") {
        }
    });
    $A.enqueueAction(action);
}
})

assuming is apex function is fetchContacts and class contactController

Salesforce - Call external API on button click and update custom field from response

2 Answers