I'm working a lightning component, which has a requirement of displaying a dynamic table.

For that, I need to iterate over a map (Map>) and display the values.

So, How can I retrieve map from apex controller and display values/key on the component ?

Apex Controller method signature –

public static Map<Id, Map<String, String>> getDataCollectionTableValues(Id dataCollectionId){

Apex method return value –

{  
   a0E0k000003aEKUEA2=   {  
      Field_10__c=test1,
      Field_1__c=test2,
      Field_2__c=test3,
      Field_3__c=test6,
      Field_4__c=null,
      Field_5__c=null,
      Field_6__c=test7,
      Field_7__c=null,
      Field_8__c=null,
      Field_9__c=test,
      ...
   }
}

Lightning helper – I’ve passed id parameter to controller method and set response to the map attribute.
 

({
    loadDataCollection: function(component) {

        var action = component.get("c.getDataCollectionTableValues");
        action.setParams({
            dataCollectionId : component.get("v.recordId")
        });

        action.setCallback(this, function(response)
        {
            var state = response.getState();
            if (state === "SUCCESS")
            {
                component.set("v.dataCollectionRecords", response.getReturnValue());
                 console.debug(response.getReturnValue());
            }else
            {
                console.debug(response.error[0].message);
            }
        });
        $A.enqueueAction(action);
    }
})

Component –

<aura:component implements="flexipage:availableForAllPageTypes,force:hasRecordId" access="global" controller="DataCollectionTableController">
    <aura:attribute name="recordId" type="Id"/>
    <aura:attribute name="dataCollection" type="Data_Collection__c" />
    <aura:handler name="init" value="{!this}" action="{!c.doInit}" />
    <aura:attribute name="dataCollectionRecords" type="Map"/>
    <aura:iteration items="{!v.dataCollectionRecords}" var="dcrRecord" indexVar="key">
        {!key}
        {!dcrRecord.key}
    </aura:iteration>

</aura:component>