[SalesForce] How to pass a record for Lightning component Attribute – Novice question

A lightning component: helloPlayground

<aura:component>
    <aura:attribute name="messages" type="String"/>
    <p>Message of the day: {!v.message}</p>
</aura:component>

I can pass the attribute value in a lightning App like:

<aura:application >
    <c:helloPlayground messages="['You look nice today.']"/>
</aura:application>

2nd Lightning Component: helloObjectAttrComponent

<aura:component >
    <aura:attribute name="item" type="Camping_Item__c" required="true"/>
        <lightning:formattedNumber value="{!v.item.Quantity__c}" style="decimal"/>
        <lightning:formattedNumber value="{!v.item.Price__c}" style="Currency"/>
</aura:component>

How do I pass the record in the lightning App below like the way I passed String? Is this even possible or the records can be only passed through apex controller?

<aura:application >
    <c: helloObjectAttrComponent xxxxxx />
</aura:application>

Best Answer

You do it the exact same way:

<c:helloObjectAttrComponent item="{!v.record}" />

You can initialize a record in the same manner as most other objects:

<aura:attribute name="record" type="Camping_Item__c" 
    default="{ 'sobjectType': 'Camping_Item__c', 'Quantity__c': 5, 'Price__c': 4.99 }" />

Note that if you pass in the value directly, as you did in the first example:

<c:helloObjectAttrComponent item="{ 'sobjectType': 'Camping_Item__c' }" />

Then the object would be immutable (can't be edited).

Related Solutions

[SalesForce] instantiate a new sobject record in lightning controller

You can certainly create a sobject instance in client and pass as it as array from the component and retrieve it as List<sObject> in the controller.

If you want to pass a specific sObject type you, have to set the sobjectType.

For eg: sobjectType to Account

Here an simple example to do it.

TestApp:

<aura:application controller="AccountController" access="public">
    <aura:attribute name="accounts" type="List" access="private"/>
    <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>

    <aura:iteration items="{!v.accounts}" var="acc">
        <ui:inputText value="{!acc.Name}"/><br/>
    </aura:iteration>

    <ui:button press="{!c.saveAcc}" label="Save"/>
</aura:application>

TestAppController.js

({
    doInit : function(cmp, event, helper) {
        var acc = [];

        for(var i = 0;i < 5;i++){
            //set sobjectType to Account, if account is passed
            acc.push({'sobjectType':'Account','Name':'Test'+i});
        }

        cmp.set("v.accounts",acc);

    },
    saveAcc : function(cmp, event, helper) {

        var action = cmp.get("c.insertAccounts");
        action.setParams({
            "acc":cmp.get("v.accounts")
        });

        actions.setCallback(this,function(resp){

            var state = resp.getState();

            if(state === 'SUCCESS'){
                console.log(resp.getReturnValue());
            }
            else if(state === 'ERROR'){
                var errors = resp.getError();
                for(var i = 0 ;i < errors.length;i++){
                    console.log(errors[i].message);
                }
            }

        });

        $A.enqueueAction(action);

    }
})

Apex Controller:

public with sharing class AccountController {

    //if sobject is specific for eg:Account,then you use List<Account> acc
    @AuraEnabled
    public static String insertAccounts(List<sObject> acc){
        try{
            insert acc;
            System.debug('acc'+acc);
            return 'success';
        }
        catch(DMLException ex){
           AuraHandledException e = new AuraHandledException(ex.getMessage());
           throw e;
        }
        return '';        
    }
}

[SalesForce] How to pass a function as a Lightning component attribute

The solution is to declare an event instead of an attribute when you want to provide a callback. Below is myButton.cmp rewritten to use events.

pressEvent.evt

<aura:event type="COMPONENT" />

myButton.cmp

<aura:component>
    <aura:attribute name="label" required="true" type="String" />
    <aura:attribute name="class" required="false" type="String" />

    <!-- Declare an "instance" of pressEvent -->
    <aura:registerEvent name="press" type="c:pressEvent"/>

    <input type="button" value="{!v.label}" class="{!v.class}" onclick="{!c.onClick}" />
</aura:component>

myButtonController.js

({
    onClick : function(component, event, helper) {
        helper.trackButtonClick(component, event);

        var event = component.getEvent('press');
        event.fire();
    }
})

This wasn't clear from the documentation, but there are two ways to handle an event. The first is to use the <aura:handler /> markup. To handle the press event of myButton, you could do this:

<aura:handler name="press" event="c:pressEvent" action="{!c.onOk}"/>

I would avoid this approach because if you have more than one button, the press event for all of them would be handled by the same action c.onOk.

The second way to handle an event is to pass a callback as an attribute in the <c:myButton /> markup. I didn't see this in the Salesforce docs but found it in an unrelated question. This is exactly what I needed. Each instance of myButton gets a unique callback.

myButtonConsumer.cmp

<aura:component>
    <!-- No aura:handler necessary. Just pass the callback as an attribute -->
    <!--<aura:handler name="press" event="c:pressEvent" action="{!c.onOk}"/>-->

    <c:myButton label="OK" class="slds-button" press="{!c.onOk}" />
    <c:myButton label="Cancel" class="slds-button" press="{!c.onCancel}" />
</aura:component>

myButtonConsumerController.js

({
    onOk: function(component, event) {
        alert('OK pressed!');
    },

    onCancel: function(component, event) {
        alert('Cancel pressed!');
    }
})

Best Answer

Related Solutions

[SalesForce] instantiate a new sobject record in lightning controller

[SalesForce] How to pass a function as a Lightning component attribute

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