SOQL Queires in VSCode

SOQL Files#

VS Code supports writing SOQL in both Apex files and standalone .soql files. When writing .soql files, we recommend that the file is located outside the directories registered in your sfdx-project.json because this is not a file to deploy to your org. The purpose of the .soql file is to provide a way to build and test a SOQL query before you import it to your Apex code. By default, a new project has a folder scripts/soql that contains an example accounts.soql file. You can use this folder to save all of your SOQL queries.

Code Completions#

VS Code supports code completions for SOQL .soql files (and will eventually support code completion in Apex files). To use this feature, you must refresh the SObject definitions so that the SOQL language server can provide code completion suggestions. Run SFDX: Refresh SObject Definitions from the Command Palette.

• To see code completion suggestions, press Ctrl+space when you’re working in a .soql file.
• To navigate between the suggestions, use the arrow keys.
• To auto-complete from the suggestion, press Enter.

Field Tracking and History objects in Apex

Field History Tracking

You can select certain fields to track and display the field history in the History related list of an object. Field history data is retained for up to 18 months through your org, and up to 24 months via the API. Field history tracking data doesn’t count against your Salesforce org’s data storage limits.

You can track the field history of custom objects and the following standard objects.

• Accounts
• Articles
• Assets
• Campaigns
• Cases
• Contacts
• Contracts
• Contract line items
• Crisis
• Employee
• EmployeeCrisisAssessment
• Entitlements
• InternalOrganizationUnit
• Knowledge
• Leads
• Opportunities
• Orders
• Order Products
• Products
• Price Book Entries
• Service Contracts
• Solutions

Modifying any of these fields adds an entry to the History related list. All entries include the date, time, nature of the change, and who made the change.

ARROW FUNCTIONS -Javascript simplified

An arrow function expression is a compact alternative to a traditional function expression, but is limited and can’t be used in all situations.

Limitations:

• Does not have its own bindings to this or super, and should not be used as methods.
• Does not have arguments, or new.target keywords.
• Can not be used as constructors.

Basic syntax

One param. With simple expression return is not needed:

param => expression

Multiple params require parentheses. With simple expression return is not needed:

(param1, paramN) => expression

Multiline statements require body brackets and return:

param => {
  let a = 1;
  return a + param;
}

Multiple params require parentheses. Multiline statements require body brackets and return:

(param1, paramN) => {
   let a = 1;
   return a + param1 + paramN;
}

Comparing traditional functions to arrow functions

Let’s decompose a “traditional function” down to the simplest “arrow function” step-by-step:
NOTE: Each step along the way is a valid “arrow function”

Relationship table – a quick look

This table summarizes whether a standard object can be:

• The master in a master-detail relationship with a custom object. Master-detail relationships involve cascading deletes and sharing rules that the parent controls.
• The lookup in a lookup relationship on a custom object. In other words, whether a custom object can have a lookup to the standard object.
• Extended with custom fields.

Standard Object	Master-Detail	Lookup	Custom Fields
Account	Yes	Yes	Yes
Campaign	Yes	Yes	Yes
Case	Yes	Yes	Yes
Contact	Yes	Yes	Yes
Contract	Yes	Yes	Yes
Event	No	No	Yes
Lead	No	No	Yes
Opportunity	Yes	Yes	Yes
Product2	No	Yes	Yes
Solution	Yes	Yes	Yes
Task	No	No	Yes
User	No	Yes	Yes

How to use continuation method in Lightning Web Components (LWC)

Continuation Class

Continuation Class is used to make asynchronous callouts using REST and SOAP services.

Continuation process executes “in the background” without the user having to wait for the response.

Continuation integration has 2 parts.

1. Build a message and send request.
2. Get the response and return the response to page.

Steps to write continuation method invoked when LWC is loaded:

Step 1 – Before you start calling an external webservice, you have to add callout URL to remote site in the Salesforce user interface. Here, remote site url name is CALLOUT_URL.

Step 2 – To make a callout, write an Apex method that returns a Continuation object with continuation = true and @AuraEnabled annotation.

@AuraEnabled(continuation=true)
public static Object sendRequest() {
 // Create continuation and set timeout in seconds.
 Continuation con = new Continuation(40);
 //More code 
 return con;
}

In this example, method sendRequest() will return the Continuation object and the callback method getResponse() will receive the response.

Step 3 – Set an Apex callback method in the continuationMethod property to be called after the callout completes. In this example, the callback method is getResponse.

con.continuationMethod='getResponse';

Step 4 – Set an endpoint for a callout by adding HttpRequestobject to the Continuation object.

Note – A single Continuation object can contain a maximum of three callouts.

HttpRequest req = new HttpRequest();
 req.setMethod('GET');
 req.setEndpoint(CALLOUT_URL);
 con.addHttpRequest(req);