HI!
I have searched a lot, but I didn't find the answer to this question: Is there any possibility to save or set the html5 local storage on SD card or locally on device? Can anybody help me?
Thanks!
I don’t think the Local Storage API lets you decide the physical location of the data being stored. It just lets you store key/value pairs in the user’s browser via JavaScript, like a cookie except that it stays local and isn’t transmitted to the server.
The browser might choose to put its local storage data onto an SD card, or the device that it’s running on, but you don’t get to inspect the physical location of the data.
See http://diveintohtml5.ep.io/storage.html#localstorage for a good guide on what local storage can do, and how to use it.
http://www.w3.org/TR/file-writer-api
I do belive this is what you would need. Read support is done and there are some chrome extensions that take advantage of it (write space), however the apps don't have write support because chrome dosen't have the api, because its still wip. The chrome folks are doing a nice job with it and I think its mostly done. I've been searching around for examples.
Related
I am currently working on an interaction event tracker for websites. One feature I am looking at adding is the capability to store specific values of elements on the pages and store them in the browser with indexedDb API.
As an extension, I would love to implement a cross-browser implementation so that I can carry the values with me across multiple machines (I use chrome on mac, personal and business machines). I know there are limitations to what indexedDB can do but isn't there a way to carry the indexedDB database between browsers till I am logged into the same account in Chrome?
Any help or direction will be truly appreciated!
I don't know if anyone got a chance to look into this but I found out that "storage" API allows you to do what I want, i.e, store data that sync over the cloud
User data can be automatically synced with Chrome sync (using storage.sync). Your extension's content scripts can directly access user data without the need for a background page.
I hope this helps anyone who goes down this path
https://developer.chrome.com/docs/extensions/reference/storage/
I am just researching and playing around with HTML5 FileSystem API. I am downloading a video from the server and saving it to the local sandbox filesystem. Say a user comes to the sites, hits download on the video, it saves to the filesystem, then the user happens to go offline.
My question is, what is the best practice for checking if video is already in the filesystem and loading it from there?
Thanks
You're asking about persistent, client-side storage of video, specifically using the Directories and System API, sometimes called "File System API." I believe this is currently only supported on Chrome 28 and Opera 16 or higher – i.e., slightly less than 1 in 3 web users right now.
Per the API spec, the users will be prompted to allow the quota for the on-client storage allotment because you're requesting persistent, not transient, storage. While the persistent client storage may be handy, it's not entirely transparent to the user.
As for determining if the Chrome or Opera user has the video stored locally, simply calling getFile() file will do it; if the file doesn't exist, it simply throws an error that you can then handle to go ahead and pull down the video. That's the standard / best practice way of determining if a file has been stored locally.
PS: Yes, I see that Blackberry mobile supports the API, too. I just don't know if either of the remaining Blackberry users will have the device storage quota available for video :-)
I have a 6MB binary file in my AppEngine backed app. I need to get this file to my GWT client to do many computations. I'm trying to avoid doing the computations on the server to save my instance hours quota. But this means I have to get the file to my client somehow.
I also don't want to download it to the app each time the app is opened, that would hurt my appengine outgoing bandwidth quota.
It would be nice to download it once, then have the client somehow store it for use the next time the app is opened.
How to best do this?
A ClientBundle? Use HTML5 Storage? Is this sort of thing just not done, and should I just do the computations on the server and send the result to the client?
The most easiest way to permanently cache the file is using application cache.
Another ways is HTML5 Storage (localStorage), but there is 2.5 MB limit. To use more than that amount, you have use IndexedDB (Chrome, Firefox, IE10) and WebSQL (Safari, Opera). A wrapper library like YDN-DB help in this case.
You can use DataResource:
https://developers.google.com/web-toolkit/doc/latest/DevGuideClientBundle#DataResource
The only problem you face is the file size. Different browsers have different limits - I've seen 5MB and 8MB numbers. If you can compress your file to be under 5MB, you should be fine with most browsers. (By the way, it's an enormous amount of data if it can't be compressed any further.)
Also, you can detect a mobile browser (or offer a different URL for mobile version), and do computations on the server for mobile users.
With HTML5's offline capabilities is it possible to create an app that will persist after the connection is lost and the browser is closed? Specifically, here's what I'd like to do:
Connect to the app while online. Download the entire app including a small database it runs on.
Close the browser and disconnect.
Open the browser again while offline and load the app from the local cache.
Thanks to Mark Pilgrim's excellent book I believe I have an idea of how to accomplish the first step, I'm mainly wondering if the last step is possible. If this is possible, I'm guessing it requires some configuration of the browser. Any settings I should be aware of that aren't obvious?
Thanks very much for any help offered.
The last step should be possible - it just depends on what extent you want to implement it to. To my knowledge it shouldn't require any browser settings. You just have to be aware of the limitations of local storage, which I believe is 5mb max at the moment (for most browsers). Obviously you'd have to perform the checks for such permissions as outlined int the Dive Into Html5 guide you linked.
The quickest and dirtiest way is to simply issue a GET request to your online app. If it responds correctly, then use the online version. If not, use the local cache. Just disguise the timeout/failed response as a 'loading' screen.
I need an offline caching system where my app can store about 0.5 MB of data. It is preferred that there is no interaction required by the user, but small amount of user interaction might be acceptable
Currently, Microsoft's Silverlight is being used to store data offline. It is a large download for the plugin, and not installed as standard on most machines.
I have been considering cookies - but they are far too volatile. I can imagine numerous reasons someone might clear their browser cache and lose all their data.
I am not sure about HTML 5 storage, and how volatile it is in practice.
I have been looking into flash, which is installed on over 97% of windows computers. It seems I can load data from a user selected file, and save data to a user selected file.
My questions...
How big is the microsoft silverlight plugin download (in MB) for windows? (I think about 8mb, but did not get clear answer from the internet)
How can users accidentally (or deliberately without realizing the consequence) clear their HTML 5 storage on common browsers?
Is there a way to get flash to store or load data from local files without user interaction?
Is there another alternative I have not considered?
Well you could use Flash shared Object storage, which will allow between 0 and unlimited space. Check this settings panel for details of your own settings to get a better idea of what I mean.
http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager03.html
Of course this does mean that the user will have to allow third party flash content to be stored locally, which is the default. Also the default storage space is 100KB, with the user being prompted to allow for a larger amount unless they have previously increased the default themselves. So that's a small draw back, but still workable.
I am not sure how you would access the shared object from within a silverlight app, as I have only used it via a Flash swf. I will do some digging around using javascript and get back to you on that.
Also there is another post that may help you:
Javascript bridge to Flash to store SO "cookies" within flash
It sounds like what you need is isolated storage.
I use it with all my silverlight apps and it couldn't be easier to use. With only a few calls you can store and retrieve data programatically.
Edit: I was thinking that your app is already programmed in Silverlight. What is your app programmed in? Is it simply HTML/CSS at the moment?