I have a legacy GWT app in which i have to load a new 3rd party .js file that provides chat functionality. The .js adds some data to the local data storage. I have noticed that when I log on to the GWT app, after login the LocalStorage is cleared.
Hence, I have the effect that the .js file sometimes writes its data to LS before, sometimes after the purge. I am seeking a way to delay the load of the .js file clientside to make sure it is written after the purge.
Currently I load the file using a ScriptInjector in a buildEntries() method where the entries for my module are prepared (sorry, I'm relatively new to GWT, cannot coin it in a better way).
Related
I've done some digging around and a lot of the threads regarding file system and how it works with Meteor seem to be pretty outdated, not to mention packages related to file storage/serving (i.e. CollectionFS). I was wondering if anyone here has deep experience with handling files in lieu of 1.4 or even 1.3 (I am currently on 1.4.1.1).
My questions are as follows:
Did Meteor 1.3/1.4 come with any changes regarding fs?
What is the general best approach to storing and serving static assets in light of Meteor 1.4?
I've seen many threads that say dynamically storing files to /public triggers a server upload, but I've tested this on local by manually copy/pasting a .png file into /public, and it only triggers a client refresh with the console message Client modified -- refreshing. Would this hold true for files added during runtime, and would it hold true in production?
Currently I am trying to stay clear from S3 or any other third party CDN's to keep a low budget, and also trying to stay clear from storing files into Mongo.
Thanks for any and all opinions!
What about setting up a shared folder or NFS folder, have your Meteor app handle the file upload, write the file to that location, and configure Nginx or whatever you are using as the load balancer to serve those files. If you worry about browser refreshed when the file is put into the public folder, you do not need to write files to the public folder right?
I am working on a Google Chrome App which reads from and writes to the sandboxed local file system.
I am accessing the file system by invoking window.webkitRequestFileSystem || window.requestFileSystem
This is a large application, and I have some code components creating and deleting files (call them the producers), and other code components displaying the files (the consumers).
For clean separation of code, I don't want the producers and consumers to know about one another. I would like the consumers to simply watch the file system, and react appropriately when files are created or modified.
Sadly, it appears that the framework provides no way to add a listener to the local file system.
Am I correct in saying that?
It looks like this is in the works and may land within the next few months. See relevant issue tracker
Can someone explain to me in simple term the concept of caching in GWT. I have read this in many places but may be due to my limited knowledge, i'm not being able to understand it.
Such as nocache.js, cache.js
or other things such as making the client cache files forever or how to make files cached by the client and then if file get changed on the server only then the client download these files again
Generally, there are 3 type of files -
Cache Forever
Cache for some time
Never Cache
Some files can never be cached, and will always fall in the "never cache" bucket. But the biggest performance wins comes from systematically converting files in the second bucket to files that can be cached forever. GWT makes it easy to do this in various ways.
The <md5>.cache.js files are safe to cache forever. If they ever change, GWT will rename the file, and so the browser will be forced to download it again.
The .nocache.js file should never be cached. This file is modified even if you change a single line of code and recompile. The nocache.js contains the links of the <md5>.cache.js, and therefore it is important that the browser always has the latest version of this file.
The third bucket contains images, css and any other static resources that are part of your application. CSS files are always changing, so you cannot tell the browser 'cache forever'. But if you use ClientBundle / CssResource, GWT will manage the file for you. Every time you change the CSS, GWT will rename the file, and therefore the browser will be forced to download it again. This lets you set strong cache headers to get the best performance.
In summary -
For anything that matches .cache., set a far-in-the-future expires header, effectively telling the browser to cache it forever.
For anything that matches .nocache., set cache headers that force the browser to re-validate the resource with the server.
For everything else, you should set a short expires header depending on how often you change resources.
Try to use ClientBundle / CssResource; this automatically renames your resources to *.cache bucket
This blog post has a good overview of the GWT bootstrapping process (and many other parts of the GWT system, incidentally), which has a lot to do with what gets cached and why.
Basically, the generated nocache.js file is a relatively small bit of JS whose sole purpose is to decide which generated permutation should be downloded.
Each individual permutation consists of the implementation of your app specific to the browser, language, etc., of the user. This is a lot more code than the simple bootstrapping code, and thus needs to be cached for your app to respond quickly. These are the cache.html files that get generated by the GWT compiler.
When you recompile and deploy your app, your users will download the nocache.js file as normal, but this will tell their browsers to download a new cache.html file with the app's new features. This will now be cached as well for the next time they load your app.
Greetings,
I'm looking for a way to launch a GWT module when a user clicks on an XML file and have the module consume the xml data. Ideally I would like to render the XML in a rich manner and would prefer to use GWT controls instead of having to lay it out by hand via xslt + javascript.
I'm supposing one way would be to point the xml to a well known xslt that creates a simple html page that forces a redirect to the gwt module but how would I transfer the xml data to said module to allow for enhanced formatting?
Another way would be to have the process that produces the xml also include the bootstrap gwt module but it would be creating multiple bootstrap instances over time and pollute the user's directory.
The use case is that a user would run this app on their local machine which outputs an XML file. If they try and view the xml file in a browser, I'd like to have the GWT module take over and present the data accordingly. I would rather they not have to go to a page and upload the data manually.
Appreciate any ideas on the matter.
TIA
If it's something that runs on the user's machine, I would recommend to ship an executable, or generate a parallel HTML file to present the data. JavaScript run from file:/// will not be able to acces the filesystem.
How do you distribute other files needed by your application that aren't in a jar file? For example, the application at http://www.javabeginner.com/java-swing/java-swing-shuffle-game . The download contains Shuffle.jar, Shuffle.bat, Score.dat, and an images folder with 3 images in it. I can see possibly putting the images directly in Shuffle.jar, but you wouldn't want to put Score.dat in the jar file because it changes. Is there somewhere you could identify this type of file in the jnlp?
The non-java files should be stored as resources. For files that change, you store the original or template file also as a resource in your jar. When the program starts, you have it check the local system to see if that file exists. If not, it creates the local file by copying the template file from the JAR resource. If the file already exists, then it is used as is.
To save files to the local system, even when running in the sandbox (unsigned), you can use the PersistenceService (javadoc / example). If your java application is signed, then you can use the regular File apis to write the file to the local machine, such as in a ".yourgame" subfolder under the user's home folder.
You can put all those files (except the scores file) in your jar file and load the contents using resource loading.
I've just deleted and restarted my reply twice now, changing my answer each time; this is confusing and needs a bit more clarification.
Are you SURE that application is supposed to be a Web Start app? On the site you linked to, it doesn't appear to be. Are you trying to take an application that was not designed as a Web Start application and change it into one that can be Web Start?
If it's not a Web Start app as your tag implies, then this question is open ended. You can distribute it 100 different ways.
If you are indeed trying to convert it into a Web Start app, you can start by packaging the images into the jar and that will alleviate your first headache if you just read them from there instead of from a File(). If it's going to be Web Start, then you need to decide how you want to keep scores. You have to decide what the scoring system is like before you can decide on how to go about it; will all the scores be kept on the web site hosting the Web Start app? Will that part still be local? If you want to get access to the local file system, you need to sign the jar, then you can extract the score.dat to the file system and do whatever you want with it if the end user accepts.
You need to figure out what you want to do before you can do it, or at least clear it up for us if you already know more than we know you know.