Adding lightning component to page Error : Unable to parse JSON response

Question

I am having an issue adding my lightning component onto my opportunity page for testing the error is

Unfortunately, there was a problem. Please try again. If the problem continues, get in touch with your administrator with the error ID shown here and any other related details. Unable to parse JSON response

my component is basic consisting of my .cmp, .js and my controller listed below:

.cmp

<aura:component controller ="AddProductsController" implements="flexipage:availableForAllPageTypes,force:hasRecordId" access="global">
<aura:attribute name="opportunity" type="Opportunity"/>
<aura:attribute name="oppId" type="String" default="{!v.recordId}"/>
<aura:handler name="init" value="{!this}" action="{!c.doInit}"/>

    <ui:button label="Card Not Present" press="{!c.AddCNP}"/>
    <li></li>
    <ui:button label="Card Present" press="{!c.AddCP}"/>
    <li></li>
    <ui:button label="Eccomerce" press="{!c.AddECOM}"/>
    <h1>{!v.oppId}</h1>
</aura:component>

.js

({
doInit : function(component, event, helper) {
    var action = component.get("c.getOpp");
    action.setParams({
        "oppId": component.get("v.recordId")
    });
    action.setCallback(this, function(a) {
    var state = a.getState();
    if (state === "SUCCESS") {
        component.set("v.opportunity", a.getReturnValue());
    }
        else{
            console.log('Error init function' + state);
        }
    });
    $A.enqueueAction(action);
},

AddCNP : function(component, event, helper) {
    List<OpportunityLineItem> Oli = List<OpportunityLineItem>();
},
AddCP : function(component, event, helper) {
    List<OpportunityLineItem> Oli = List<OpportunityLineItem>();
},
AddECOM : function(component, event, helper) {
    List<OpportunityLineItem> Oli = List<OpportunityLineItem>();
}
})

Controller

public with sharing class AddProductsController {
 @AuraEnabled
public static Opportunity getOpp(Id oppId){
    return([Select id, Name
                            From Opportunity Where id=:oppId]);
}

}

As far as I am aware I have implemented it correctly and the opportunity object just be being parsed onto the view. Any ideas?

Answer 1

Posting an answer just so the thread can be closed.

List<OpportunityLineItem> Oli = List<OpportunityLineItem>();

is not the appropiate way of declaring a list of type OpportunityLineItem in JavaScript.

Your Javascript code doesn't know what is OpportunityLineItem, so for JS, its just an array to which you can put any one kind of items.

So declare an array like this:

var Oli = [];

then push items into it:

Oli.push(oliItem);