5

I want to detect whether a server feature is enabled in my component during init, set the response into a Boolean attribute, then, if so, not set that again.

This is with Platform Encryption. So technically the feature license can be provisioned, but not enabled as the org has not had a first Tenant Secret record generated.

So if the init query to populate the component data returns with no records, I know there is no TenantSecret record, Platform Encryption is not enabled, and my UI can respond.

If it is enabled, I set the flag to true, and never worry about it again in the component lifecycle.

Here's the rub

The function I'm using to populate the data should work fine for refreshing data at other points in the component lifecycle. I don't want to write one refresh function for init, and other for other times. But I'm having trouble detecting the "init" event in my controller/helper.

I'm using standard init event registration in the controller.

<aura:handler name="init" value="{!this}" action="{!c.doInit}"/>

I would have expected to then be able to detect this is the init event as below in my controller, but all the pertinent calls return undefined or information that is not useful:

doInit : function(component, event, helper) {
  console.log(event.getName()); //Undefined
  console.log(event.getParams()); //returns only instance of component
  console.log(event.getSource()); //tried this just for giggles, but also undefined

So if I want to run some code in a reusable method only during the init cycle and ignore it at all other times, how do I do this?

(I have found a workaround, but will wait and see what people come back with.)

  • Hey Peter, I'm not aware of an officially sanctioned way to do it but here's another workaround: event.Wb.g.name will equal 'valueInit' if called from the init handler. – Rob Sep 12 '15 at 18:13
  • I guess you could also have the init handler pass a flag parameter to your reusable function, and make that flag determine whether the conditional code is executed. – Rob Sep 12 '15 at 18:25
  • It would seem to me that you'd want the Apex controller to return the value of the flag and also set the equivalent flag on the client site as part of the init. You could write that to the console.log. – crmprogdev Sep 12 '15 at 20:26
  • Great suggestions. Calling the event.Wb.g.name seems precarious. Especially with LCF's newness, these kinds of undocumented Properties could very well change. The the enabled state of the feature is not the worry. It is knowing the short period of time that any handler is executing in the init state versus all the other states (render, reRender, afterRender, etc.). – pchittum Sep 12 '15 at 21:38
2

My workaround basically consists of tracking the init state on the component.

So in my init handler I'm doing this:

doInit : function(component, event, helper) {
  component.isInit = true; 
  helper.fetchComponentData(component, event);

The tricky part that I'm not satisfied with is how to get the the flag to be unset at the right time. At first glance this might look good:

doInit : function(component, event, helper) {
  component.isInit = true; 
  helper.fetchComponentData(component, event);
  component.isInit = false; 
}

But fetchComponentData is firing off server actions that get queued up, so they end up completing after component.isInit = false; actually happens. This probably doesn't surprise many of you, but maybe a few people will read that and have an ah-hah moment.

I was hoping using setTimeout might push function to the bottom of the event queue that would end up firing after the response from my server call, so I tried this:

doInit : function(component, event, helper) {
  component.isInit = true; 
  helper.fetchComponentData(component, event);

  window.setTimeout(
    $A.getCallback(function(){
      component.isInit = false;
    }),1000                 //also tried with 1, but that didn't work
  );                        
}

This works, but I don't like there to be some arbitrary 1000ms delay that hopefully ends up being after my server callback.

The most predictable, I think, ends up being to put component.isInit = false as the last thing that my server callback does. But if the internal mechanics of the fetchComponentData function ever change, it could lead to unpredictable results.

This last option is what I have chosen for now. Ideally, I would like the framework to be able to tell me when init has been triggered, and automatically, once all enqueued actions have finished their callbacks, set it to false. But I don't see a better way to do it for now.

  • 1
    Did you ever find a better way? right now I am trying to show a spinner on aura:waiting but the spinner keeps firing multiple times due to LEX events and I cannot get it to only fire for my component. Seems that the waiting on my component is called like 30 times during the page loading. Only recourse now it to add a spinner to every component and manually call it every time. Lots of code bloat – Eric Jan 9 '17 at 20:59
0

Ran into this same issue today (reusing init function with other events). I'm currently using 2 different event methods to distinguish the origin and perform logic a bit differently to extract event parameters where it applies. These methods are getType and getEventType.

INIT

doInit: function(component, event, helper) {
console.log(event.getType()); //returns aura:valueInit
console.log(event.getEventType()); // returns VALUE }

METHOD CALL FROM PARENT

doInit: function(component, event, helper) {
console.log(event.getType()); //returns aura:methodCall
console.log(event.getEventType()); // returns COMPONENT }

If trying to use with multiple events it might not be good enough as they will return the same value (but for this simple use case to distinguish init it works just fine). I'm still puzzled why the event.getName() returns undefined in both cases (as shown in the Question itself) - seems that would be the best way to determine which event is invoking the action.

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