unityscript API change: AddComponent with custom type

So I get that an api change was made so that:

gameObject.AddComponent("rigidbody")

becomes

gameObject.AddComponent.<rigidbody>();

cool. however I have an issue and since theres no documentation so i'm asking how i should approach this.

I have a custom component i'm trying to instantiate (this is a state machine), but it passes in a string, that string is the name of the component to be added.

var foo:String = "myComponent";
gameObject.AddComponent.<foo>();

however, this if course just adds the component "foo" to my object, not "myComponent"

var foo:System.Type = System.Type.GetType("myComponent")
gameObject.AddComponent.<foo>();

this doesn't work either, claiming:

The name 'foo' does not denote a valid type ('not found').

so after these api changes.. how are you supposed to dynamically add components from variables? The ease of doing this is one of the things i really appreciated about UnityScript.

 

so after having tested this trying to figure out the problem, it seems System.Type.GetType(a string variable) does not return the correct type. or atleast it doesn't behave like one would desire.

if I enter the type (camAim) as the type (there is a component called camAim), and call:

var state:String = "camAim"
typeof(System.Type.GetType(state)))

i get "System.MonoType"

but shouldn't this instead be of type camAim? or System.MonoType.camAim ?

because right now, if i call this code in the game:

state = "camA

currentState = state;
currentStateObj = gameObject.AddComponent(typeof(state));
currentStateObj.Enter();

the game will lock up and i have to force quit to close. Ive submitted a bug report and they said "seems like an infinite loop". which is odd.. as there is nothing like that in my code. if i comment out

currentStateObj = gameObject.AddComponent(typeof(state));

then the game does not crash and runs just fine. The crash is clearly related to the AddComponent function

 

hey Vagaus,

case number: 648845
http://fogbugz.unity3d.com/default.asp?648845_durj6fcf16vjguf0

i just checked and they marked it as closed for some reason. DEFINITELY not closed. I just replied to the QA guy with a simplified scene, but now im not sure if they'll even get it with the case closed.

i'm sending the package here.

just press "spacebar" and it will lock up the game / editor and you'll have to force quit. beware. It is the simplest repro case of this bug.

its ground my development to a hault. really hope you see it on your end.

 

i replied to your email. Thanks for taking a look at this. i still think something is wrong at a low level. let me know if you didn't get it

Matt R

 

Still trying to get this resolved. SO close now.

Just to update the community, in Unity Script if you want to get the type of a component, this is the syntax

// WRONG
gameObject.AddComponent(System.Type.GetType("Rigidbody"));

// RIGHT
gameObject.AddComponent(System.Type.GetType("UnityEngine.Rigidbody, UnityEngine")); // right type name used

unfortunately you can still not add custom components through a string

var state:String = "actionNuetral";
gameObject.AddComponent(System.Type.GetType("UnityEngine."+state+", UnityEngine")); // right type name used

will unfortunately return Null still.

I will keep posting while trying to resolve this.

 

Instead of GetType try typeof and don't use a String:

Code (csharp):

1.  
2. gameObject.AddComponent(typeof(Rigidbody));
3.  

Or a better question... why resolve the type at all if you already know what it is? If you already know you need Rigidbody for example... why convert that to a string? Since you're using UnityScript, just do:

Code (csharp):

1.  
2. gameObject.AddComponent.<Rigidbody>();
3.  

Unless I'm missing something... there's no need to convert to a string. So let's say you have a monobehavior with a type of myComponent... don't use the string, just do:

Code (csharp):

1.  
2. gameObject.AddComponent.<myComponent>();
3.  

If myComponent is a variable that references a component from another object, and you want to add it to your current object then do:

Code (csharp):

1.  
2. gameObject.AddComponent(typeof(myComponent));
3.  

 

thanks for the reply. the entire problem is that the types im trying to add come in as strings.

i should add. this is really a Unity 5 issue. Theres some mysterious syntax for casting strings into types that no one at Unity seems to know after the API change.

after 10 emails back and forth, no one seems to be able to understand that I, matt radford, have a need to cast strings to types.

var state = "actionAim" (actionAim is a component)
gameObject.AddComponent(state) (this is how this worked in 4.6 and below)

now.. there seems to be no way to do this. The general response is people seem to be very confused WHY im doing this. which is fine. when this project was started I didn't know as much about Unity as i do now and the state machine implementation was created this way. it is now the backbone of my game for better and worse (it actually works really well! ).

So i do know that there are better ways to add components, but this is the way I NEED to add them. And since this worked in Unity 4.X when the API change was never announced I made that decision and I do plan on sticking with it. My worse case scenario is never getting to use Unity 5 and sticking with 4.6

I'm grateful for Unity and their support team. They are very helpful. But I am a bit frustrated at this point as every damn email seems to be from a new person who has not read any of the previous emails to do with the case. So every time its this back and forth about "Well don't cast them as strings, reference the type directly". And I get it. It wasn't the best way to do it. But at this point i'm just looking for an answer of "this is no longer supported" or "oh yeah.. its weird that doesn't work"

I'm pretty sure in the end its going to be something really really simple and i'll laugh it off.

sorry to vent a little. I really do appreciate the community and Unity's dev / QA team.

 

yeah, originally when i submitted the ticket I had found that

1. var state = "actionNeutral";
2. gameObject.AddComponent(System.Type.GetType(state));

does work. however, it seems to work only once, when the game first starts up, then at runtime whenever you try to perform this operation Unity goes into an inifinite loop. You were able to repro this from the simple example scene i prepared.

did you find out why

var state = "actionNuetral"
print(System.Type.GetType(state)) will always return null ?


because i think thats where the infinite loop seems to come from
the game searches over and over for "null" somehow..