Single image with GWT 2.4 requires an ImageResource? - gwt

I was just adding a single image to a GWT 2.4 application I was working on. I just put it under the images folder in the war and I had it working properly until I would compile it. Then it would get deleted from the folder. If I remember correctly, from working with older versions of GWT, you could just put an image in this folder to use it.
It just took a few minutes to convert the code to use an ImageResource, but do you have to use an ImageResource for just one image or is there another way to do this?

The class ImageBundle is deprecated, try to use ClientBundle instead.
Instead of putting the file in the war folder, which is typically generated, try putting it in a folder called public/ in the same directory as your client package. The compiler will move it then into your module directory.
And finally, ClientBundle (and ImageBundle, but don't use it) will automatically try to sprite your images where possible, and in some cases include the image in your main html download so that the user only needs to download and cache one large file instead of several files - even for individual images it can be worth it for repeat users of the page, to ensure that no caching issues ever occur.

Related

Can we overlay the file to our custom path

Can we overlay the file to our custom path or we have to overlay the file to exact folder structure location as in libs?
For example, I want to overlay the constants.js (/libs/cq/ui/widgets/source/constants.js) file, in this adobe recommended Copy this file to /apps/cq/ui/widgets/source/constants.js for overlaying, but in my project that folder structure is not there, so I have copied to the custom path in apps folder and tested the changes and overlaying is working fine.
The file needs to have the same path as the one in libs except for replacing 'libs' with 'apps'. It does not work with custom paths*. If the project does not already have the structure, you can always create it. Don't forget to update the META-INF/Vault/filter.xml file to register the new path with projects package definition.
*Technically you can change the configs to add new searchpaths. But do remember that you might have to share the AEM instance with different tenants and sticking to the usual conventions goes a long way in having a predictable setup. I honestly don't see a reason to do this, it is already an acceptable practice to overlay under '/apps'. The filters on package provide enough flexibility to get along with other tenants while modifying similar areas.
I think you want to create the overlay in your custom project under /apps. If my assumption is correct, then you can certainly do it.
Taking your example in consideration, /libs/cq/ui/widgets/source/constants.js can be overlayed to /apps/<your-project>/cq/ui/widgets/source/constants.js by adding an entry in the Apache Sling Resource Resolver Factory configuration.
See this answer for the detailed steps. I hope this helps.

Unity Asset Bundles - Which Files Do I Deploy?

I have created some asset bundles from my Unity assets using the directions given in the Unity documentation section on AssetBundle Workflow. After running the "Build AssetBundles" command, each asset bundle results in four files: myasset, myasset.meta, myasset.manifest, myasset.manifest.meta.
Now I am ready to deploy these bundles to a web server and implement downloading/caching in my Unity project. I have found numerous examples such as this that show the download URL to be a single file with a .unity3d extension. This is leading me to conclude that I am missing a step - I assume that all four of my files will be required by the app and that I have to do something to combine them into a .unity3d file first.
What file(s) do I need to deploy? Are there any additional steps that I need to take before my file(s) are ready to upload? Thanks in advance for any advice!
Just myasset will suffice.
Sometimes people optionally add .unity3d as a filename extension to their Asset Bundles. It is just a community convention, and is completely optional. Source (copied below)
Vincent-Zhang
Unity Technologies
Just a reminder, we don't have an official file extension ".unity3d" for asset bundle, it's not mandatory. You can use whatever file extension as you want, or without file extension.
But usually people use ".unity3d" as the file extension just because we used it in the official sample code at first time...
Unity creates the .meta files for all assets- you don't have to worry about those. In short, your myasset file is enough. I do not add file extensions to mine. Do note that if you use the strategy shown in the example that you shared that the client will re-download the bundle from the server every time. You need to additionally provide a version number if you want to take advantage of caching. You can see this in some of the method overloads here, the ones that have a Hash128 or uint "version" parameter. Caching is great because you can use the bundle that is already saved on the device next time instead of downloading from the server when no changes have occurred. The version/hash number you provide essentially gets mapped to the file name. Whenever a matching version is found, the file on disk is used. Update the version number to something else when the content changes to force the client to download anew.
You may want to reference the .manifest file for the CRC value listed there. You may have noticed a crc parameter in the link I shared as well. This can be used to ensure data integrity during transmission of the bundle data. You can make sure the downloaded content's CRC matches that of the bundle when you created it.

How I can clear JRE cache dynamicly in java applet

Here is code:
<applet code="ATest.class" archive="ATest.class?v=200406181300">
</applet>
I want to clear existing cache and load the new one when it loads 1st time.How can i do in java applet?
I tested it in Firefox 0.9 and it loaded and ran the class. The idea here
is that when you change the class, you change the [v]ersion in the ARCHIVE
attribute. That should force the browser to get a new copy of the class
file, since the "archive" is now at a different URI, and since the
"archive" is the .class file, it might work (unless the user agent
disregards ARCHIVEs that are classes, which is entirely possible)
I don't think the applet can so this.
But I don't think it needs to either. If the changing the v parameter to a different value isn't sufficient to get the browser to request a new copy of the class, then put it into a JAR file and arrange that the JAR file's name changes each time you want to deploy a fresh version.
I should note that forcing the browser to download a fresh copy of a class if it hasn't changed is a bad idea. It won't achieve anything useful. On the contrary, it will waste server and network resources, and it will make the page load slower.
First, read your question: Why would one update an Applet, "when it loads 1st time"? If you mean the second time, when the plugin tries to load it from its own cache, than just use a new codebase, maybe a new one for every visit/or.

How does GWT ClientBundle caching work?

I am trying to better understand the use of GWT ClientBundle and caching.
If I have a large text file, for example, that I'd like to make available to my client, I can use
public interface MyResources extends ClientBundle {
public static final MyResources INSTANCE = GWT.create(MyResources.class);
#Source("myText.txt")
public TextResource myText();
}
//-- then later to use the text
String text = MyResources.INSTANCE.myText().getText();
Does this mean that the file "myText.txt" would be downloaded from the server the first time the client runs the app, and then the file would be stored in the browser's cache so that in future uses of the app, the file does not need to be downloaded?
If so, what happens if I change "myText.txt", does the app know to get the new version?
Finally, if the file is indeed stored in the cache, how then is this different from local storage in HTML5?
Thanks.
As Daniel Kurka already mentioned, the resources can be inlined in the js file (a *.cache.* file) where the rest of the compiled GWT code lives.
Inlining does not occur for all resources in a client bundle. E.g. large images are never inlined, it can also be prevented with #ImageOptions.preventInlining(), and it doesn't occur for ExternalTextResources.
What's common for both cases is, that the results will be in *.cache.* files, with unique names that change automatically whenever the contents of a source file change (you'll have to recompile the GWT app though!)
This allows the server to deliver these files with appropriate caching HTTP headers (you'll have to set this up yourself!) For the client this means, that it will not only be able to cache the contents (which it does anyway, even if those headers aren't set), but it can even skip asking the server, if a newer version exists.
The big advantage of ClientBundles is, that the file names will change automatically. The biggest disadvantage is, that you must recompile your GWT app, when a resource changes. If you don't want that, then it's better to use some other approach to load the files: You can still make the browser cache any file you like (by setting the HTTP headers), but then you'll have to be careful to manually give them a new name, when the content changes.
You should use an External Text Resource if you want it to be loaded on demand and not as a part of compiled JavaScript.
https://developers.google.com/web-toolkit/doc/latest/DevGuideClientBundle#TextResource
If your users need the entire file, use one text resource. If users need parts of it, split this file into separate smaller files: only the requested file will be loaded when needed.
The external text resources can be cached like all other static files.
Files that are inside a clientbundle get inlined into your compiled javascript. They will not be downloaded separately. If you want to download a resource at a given time you can easily use request builder for that.
If you don`t want to download the file immediately but you still want to inline it, you can use code splitting and put the bundle into another part of your app.

Netbeans creating a dist jar with all images etc included

I am trying to distribute a netbeans project however the jar it creates and the contents of the dist folder are dependant on some image files which i included into the project - however these images are not in the dist folder and I cannot workout how to make things work so I can export the project in a distributable format including all the things it needs.
Can somebody please tell me how I can export a project which runs within Netbeans without using the project's /dist folder which includes everything it needs?
Cheers
Andy
One way to achieve this is to add a folder (f.i."resources") in your project's src dir. Then copy the images to that dir. Now the images should get included when you build the project (if I remember correctly). Accessing the files can be accomplished with "getResourceAsStream"...
If whatever resources you are interested in are in the classpath, packaged in the jar, war, or the distribution, you can retrieve them by getting resources.
The convention is indeed to have a directory named 'src/resources' that serves as the root for this. Depending on the amount and scope of the resources you are using you may also want to add a sub-directory hierarchy to keep the organization and state of the resources manageable.
Also, not that a resource can be any file, an image, sound, text, xml, binary, etc. no limitation.
Finally, the call will look like this if you are using an object method:
getClass().getResourceAsStream("resources/myResource") - or - getClass().getResource("resources/myResource")
depends on if you want a stream or just the URI at that point in the code. Typically one would use the URI for delegating the processing of the resource elsewhere and the stream form when you are processing it in-line.
For a class method, you will need to do something more like:
new Object().getClass()...
The think to keep in mind here, is eventually this is resolving to the class loader and it is from that class path that the resource will be fetched.
You can add images the same way:
final Image image0 = Toolkit.getDefaultToolkit().getImage(getClass().getResource("images/1.png"));