Image documentation no help...

So I'm trying to do a simple task. I have an Image in a prefab whose sprite is not set. I want to set that dynamically in code. I go to this page:
http://docs.unity3d.com/ScriptReference/UI.Image-sprite.html
and it is no help.

There is no code example of how set that value. This is what documentation is supposed to teach people. It would tell me so many things, how to pull an asset off my hard drive (I know I would only reference it, and at build time the compiler would do the real work), how to assign that value, what data type it takes, and there should be a "here's the way we want you to do that example" as well as "here's the quick and dirty way" example. But all I find is:

"UI.Image.sprite
Switch to Manual
public var sprite: Sprite;
public Sprite sprite;
public sprite as Sprite
Description
The sprite that is used to render this image.
Copyright © 2014 Unity Technologies"

Teaches me nothing, documents nothing.

 

So I know there are a lot of extraneous concepts in this code segment - but it's at least something.

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.UI;
3. using System.Collections;
4. using System.Collections.Generic;
5.  
6. public class GameManager : MonoBehaviour
7. {
8.     [SerializeField] Image _Map;
9.     [SerializeField] Sprite _Locked;
10.     [SerializeField] Sprite _Cleared;
11.     [SerializeField] Sprite _Active;
12.  
13.     // Use this for initialization
14.     void Start ()
15.     {  
16.         // Retrieve list of arenas
17.         List<Arena> ArenaList = DataFacade.GetArenaList();
18.         // Instantiate and position them
19.         foreach(Arena aArena in ArenaList)
20.         {
21.             aArena.GameObject = (GameObject) Instantiate(
22.              Factory.Instance.GetObject(Objects.ARENAPOINT), Vector3.zero,
23.              Quaternion.identity);
24.             aArena.GameObject.transform.SetParent(_Map.transform);
25.             // Arena position is applied as an "offset" of map position
26.             aArena.GameObject.transform.position = new Vector2(
27.              _Map.transform.position.x -  aArena.X,
28.              _Map.transform.position.y - aArena.Y);
29.            
30.             // This is what we want to show in this example -- that the sprite is
31.             // being set to the "public" variable that must have been
32.             // pre-populated by the editor before running this code. We call this
33.             // concept the "editor hole", meaning it is the "hole" you can use to
34.             // put prefabs from the editor into your code for instantiation.
35.            
36.             // Set the progress icon
37.             Image aImage = aArena.GameObject.GetComponentInChildren<Image>();
38.             if (GameManager.Instance.User.ArenaNumber > aArena.ID)
39.             {
40.                 // Clear
41.                 aImage.sprite = _Cleared;
42.             }
43.             else if (GameManager.Instance.User.ArenaNumber < aArena.ID)
44.             {
45.                 // Locked
46.                 aImage.sprite = _Locked;
47.             }
48.             else
49.             {
50.                 // Active
51.                 aImage.sprite = _Active;
52.             }
53.         }
54.     }
55. }

The code does not explain what you have to do in the editor to prepare the Sprite and a link should be provided to those instructions.

Personally I don't like this code - I'd prefer if there was a method to reference the source sprite on my hard drive (in the project space) and at build time the compiler would correct that reference to where that sprite would be on the target machine at run time.

And how do you set that sprite from dynamically downloaded content??? All this needs to be documented or have links from this point to where those concepts are explained.

 

1) Import your sprite images into a folder called Resources, literally name it that. Unity searches that folder for dynamic assets, even though you don't need it for pre-applied assets (like the prefabs, which you're not doing, hehe)
2) Load the Resource with this: yoursprite = Resources.Load( Path_and_name_of_file.jpg, typeof(Sprite) ) as Sprite;
3) gameObject's spriteRenderer.sprite = yoursprite;
Edit, the path is relative to Resources. So if you have Resources/Folder1/image.jpg then your path_and_file is Folder1/image.jpg, forward slash is used no matter what. I'm on windows, for example, and it works that way.

Hope that helps. Graham, I do like your post, but the reason I didn't hit "like" is bc you're the Unity dude, but I'm the one answering! Humor aside, I believe we have the same goals, I'm willing to work with you on getting that going after my stuff is finished from the other post

 

Unfortunately the "Resources" folder has its own drawbacks. It moves those assets to every build so Windows, IOS, and Android all get the same resources. To avoid that you have to build three projects, and put Windows assets in one, IOS in another, and Android in the last.

But I see you mentioned dynamic resources. How are you loading resources to that folder at run-time?

And I am doing prefabs (see code above) my Factory.GetObject method returns a prefab whose Sprite is not set.

 

Don't use Resources for sprites, since it prevents auto-atlasing. There is no Resources folder in a build; everything is compiled into an asset file. For loading external assets at runtime you need to use System.IO.File functions (or the WWW class using "file://").

--Eric

 

So why is there not a user-maintainable officially sanctioned wiki? That's what most companies do when they have an API and no will to create proper documentation for it. Create a wiki, stub it with the existing documentation, and open the doors.

Here's an example of what a properly documented function should look like:
https://msdn.microsoft.com/en-us/library/windows/desktop/ms632679(v=vs.85).aspx

Versus what I can only describe as obviously code-generated documentation:
http://docs.unity3d.com/ScriptReference/Serialization.SerializedStateReader.html

At work I'm firmly against code-generated documentation. Case in point?
https://developer.gnome.org/gtkmm/stable/classGtk_1_1Container.html

Unity is a development environment. The API is ~the~ product you are selling, the editor being the tool to work with the APIs in an easier format. I would imagine properly documenting the API would be one of the first things you would do:

Step 1) Write the user story for the function/feature
Step 2a) Have a document writer write documentation based on the requirements
Step 2b) Have a development team implement the feature
Step 3) Test the feature against the generated document and requirements
Step 4) Release the feature along with the document.

I'm imagining it's more like:
Step 1) Developer gets random feature from the sprint.
Step 2) Developer implements the feature into dev
Step 3) QA tests and certifies the feature
(and then at SOME point in the future)
The documentation guy goes in and adds documentation for the function.

The simple fact that you have completely empty documentation pages shows there is no QA for your documents. You generate the documentation from code or a data file and put it out there.

This isn't really a rant to unity so much as a rant to many APIs out there that seem to throw developers under the bus and rely on the "community" (aka the customers) to pick up the slack.

 

I think you missed Graham's post above:

 

I didn't, "can" and "hope" are not the same as "will" and "am confident". In fact, those words instantly tell me that there is more to what he is saying, which is why his phrasing has a very political and pessimistic tonality to it. I get that they ~want~ to do it, I mean who wouldn't? I just have a feeling it's not going to get done due to some higher up or external influence, hence my rant post

 

I get it, I really do. I work as a software engineer for a company that lists Walmart and Target as clients so I get the whole "priorities" thing. Documentation simply doesn't come across as "progress" for large/important clients. I honestly don't mind starting up a documentation project as I really love Unity and I'd hate to loose users to Unreal Engine or other systems due to poor documentation. Do you think there's any way the unity team could provide some sort of serializable (xml, json, binary, etc) dump of the documentation? If so, I could use it to seed a documentation site and then start adding valuable information from there? Maybe even a css/image kit to match the unity site look and feel? I'd use bootstrap as a base as responsive/mobile support would be a necessity.

If so ping me, I can throw up an azure instance and whip up an MVC site pretty quick. I know you guys use PHP (which explains the 2600 lines of html that comes back on this page ), but if I'm going to do a site, I'd like to do it right.

And if there's anyone else out there who'd like to help set it up, let me know as well. I can't possibly fix the documentation issues by myself.

 

So like, I couldn't get any of my code-determined images to load in my cards until I found the Resources thing after literally 5 hours of searching. So, thanks for the advice guys, and now I'm mostly clueless as to which method I should use. I'll reread your posts on using the system IO and such

 

You should go for it. I myself am teaching a junior developer, trying to tell him to always use the docs as the first port of call. Followed by him returning to me, having found a half baked attempt at an explanation of some function with the bare minimum in terms of code examples provided.

Anyway, you should your own thread for this, so people can find it, I for one would be happy to chip in with some of the obscure editor classes at least