Salesforce: How to get field value in aura attribute and use if statement in component

Question

I'm new to Salesforce development, but not new to web development (Angular, React, C#, JS, etc...). So it's been very frustrating that I cannot get something so simple as the example below to work. I want to display content based upon a condition of a custom fields value:

<aura:component controller="MyTestController" implements="flexipage:availableForRecordHome,force:appHostable,lightning:actionOverride,force:hasRecordId">
    <aura:attribute name="oppty" type="Opportunity" />

    <article class="slds-card">
        <aura:if isTrue="{!v.oppty.MyCustomField__c == 'hello'}">
            Hello
        </aura:if>
        <lightning:button label="Click Me" onclick="{!c.handleClick}" class="slds-m-top_medium" />
    </article>    
</aura:component>

In my JS controller, when I console.log() my attribute oppty, I get undefined:

({
    handleClick : function(cmp, event) {
        var myOpportunity = cmp.get("v.oppty");
        console.log(myOpportunity); // or
        console.log(myOpportunity.MyCustomField__c); 
    }
})

I guess a better question is this: How do I get a value from a field of object Opportunity and bind it to the aura attribute?

Answer 1

I see you have not included the code for fetching the record and not even having any call to APEX to fetch the data.

There are 2 ways to get the data.

1. From lightning component Refer

<aura:attribute name="recordId" type="String" />
<aura:attribute name="opty" type="Opportunity" default="{'sobjectType': 
 'Opportunity'}" />
<aura:attribute name="recordLoadError" type="String" />

<force:recordData aura:id="recordLoader" recordId="{!v.recordId}"
    fields="Name, MyCustomField__c"
    targetFields="{!v.opty}" targetError="{!v.recordLoadError}" />

2. Using APEX call

   Create AuraEnabled method in APEX class and consume in component helper.