Async lookup for sidenav instance logs an error in the console (when it should just wait until the instance is available).

[yoav-zibin]

From the docs:
https://material.angularjs.org/latest/api/service/$mdSidenav

// Async lookup for sidenav instance; will resolve when the instance is available
$mdSidenav(componentId).then(function(instance) {
$log.debug( componentId + "is now ready" );
});

However, when I do that, I get an error in the logs:

angular.js:13550 SideNav 'left' is not available! Did you use md-component-id='left'?
(anonymous function) @ angular.js:13550findInstance @ angular-material.js:15747(anonymous function) @ angular-material.js:15712(anonymous function) @ index.dev.html:520invoke @ angular.js:4665(anonymous function) @ angular.js:4473forEach @ angular.js:322createInjector @ angular.js:4473doBootstrap @ angular.js:1746bootstrap @ angular.js:1767gamingPlatformInitFinished @ index.dev.html:530(anonymous function) @ app-gameinvite-common-code.ts:258trigger @ angular.js:3166defaultHandlerWrapper @ angular.js:3456eventHandler @ angular.js:3444

Even when passing true, it still logs the error:
$mdSidenav('left', true);

Except the error logs, things work correctly: the promise is resolved correctly :)
The problem is that it spams the error logs (and i have protractor tests that make sure the error log is empty).

The problem is in this code:

/**
   * Service API that supports three (3) usages:
   *   $mdSidenav().find("left")                       // sync (must already exist) or returns undefined
   *   $mdSidenav("left").toggle();                    // sync (must already exist) or returns reject promise;
   *   $mdSidenav("left",true).then( function(left){   // async returns instance when available
   *    left.toggle();
   *   });
   */
  return function(handle, enableWait) {
    if ( angular.isUndefined(handle) ) return service;

    var instance = service.find(handle); // THIS IS THE BUG: if enableWait is true, then it should use waitForInstance (and not findInstance).


Because findInstance logs an error if the instance is not ready:
function findInstance(handle) {
      var instance = $mdComponentRegistry.get(handle);
      if(!instance) {
        // Report missing instance
        $log.error( $mdUtil.supplant(errorMsg, [handle || ""]) );

See:

   var service = {
        find    : findInstance,     //  sync  - returns proxy API
        waitFor : waitForInstance   //  async - returns promise
      };

[yoav-zibin]

BTW, the documentation is buggy as it should mention the boolean argument (true):
$mdSidenav(componentId, true).then(function(instance) {

The workaround I found to avoid the log.error is to use [the undocumented] $mdComponentRegistry as follows:

$mdComponentRegistry.when('left').then(function() {
  // Now you can use $mdSidenav('left') or $mdSidenav('left', true) without getting an error.
  $mdSidenav('left').toggle();
})

[crisbeto]

This happens because firing the $mdSidenav immediately in your controller is earlier than the directive controller which registers it with the $mdComponentRegistry. I'll try to see if there's a workaround on Material's side, but in your case wrapping it in a $timeout should do the trick.

[yoav-zibin]

I initially tried $timeout, but a low timeout (say even 200 milliseconds) wasn't enough to solve it --- maybe my macbook pro is slow :D

Then I found a better workaround using:
$mdComponentRegistry.when('left')

I believe this is what material should do:

return function(handle, enableWait) {
if ( angular.isUndefined(handle) ) return service;

if (enableWait) return waitForInstance(handle); // which calls $mdComponentRegistry.when(handle);

Simple :)

[crisbeto]

Yeah, passing in true does the same behind the scenes. We shouldn't throw errors in that case though.

[yoav-zibin]

The current code doesn't do the same because it first tries to find the instance (which logs an error).
Note that it doesn't throw an error (just console.error):
$log.error( $mdUtil.supplant(errorMsg, [handle || ""]) );

Again, I believe the fix is a one line change:

Current code:
return function(handle, enableWait) {
if ( angular.isUndefined(handle) ) return service;

var instance = service.find(handle);
return  !instance && (enableWait === true) ? service.waitFor(handle) :
        !instance && angular.isUndefined(enableWait) ? addLegacyAPI(service, handle) : instance;

};

New code:

return function(handle, enableWait) {
if ( angular.isUndefined(handle) ) return service;
if (enableWait) return waitForInstance(handle); // NEW LINE
var instance = service.find(handle);
// I also simplified the line below
return !instance && angular.isUndefined(enableWait) ? addLegacyAPI(service, handle) : instance;
};