Okay, we talk and hear lot about creating mobile app using javascript and html. I was trying to write one app myself forgetting that some real programs also need to store and access at least, the information stored by the program. I intend to user only the browser of the mobile app and it is offline. Basically, it is just a program written using js. Since the browser is not allowed to create and store the data in the user's disk, how should I approach it? Storing the data in cookies is one of the option, I guess. I am new to web programming so please bear with me if I say something stupid. However, cookies can be inadvertently deleted.
So my question is: How can I manage a 'small storage space' in mobile device if I am using a html and js to create my app?
Web storage is supported by almost all modern browsers
http://caniuse.com/#feat=namevalue-storage
If you are looking for offline web applications, it is not supported from old Internet Explorer
http://caniuse.com/#feat=offline-apps
Here are a couple of useful links:
http://diveintohtml5.info/storage.html
http://diveintohtml5.info/offline.html
I believe all modern phones support LocalStorage.
In HTML5, there are a couple of ways to save information the way you want.
LocalStorage and WebDatabase
Although, if you want to do an App for iOS I recoment Web Apps, that allow you to create offline HTML application that the user see as a normal app.
Related
I would like to access a special hardware (a penta scanner, for the wisest ;) ) from a web page.
The aim is to retrieve the information from the scanner and compute it on server side.
The problem here, is that I have to summon functions from a DLL that has to be on the client side. I have two leads for that:
Develop a COM DLL and use ActiveX
Try to get through a homemade extension for a web browser in order to communicate with the local DLLs.
I've tried the first option, and I got stuck and I've posted another thread about it. Anyway, even if it works, there are too many constraints about it (as to use IE or the fact that even Microsoft is not fond of this feature and banned it from edge).
The second method is something that I found on another forum but, I do not understand how I can interact with a browser extension (whatever the browser).
So what I am asking is:
Is it possible to use a web browser extension as a medium to a local DLL and if so, would you be so kind as to give a hint about how to do ar anything that might look like a start about how to do it (even just some key words to use on google, since mine didn't get anything)....
Thanks.
Based on my understanding, the motive to develop an Extensions is to enhance the feature and functionality for particular web browser.
You cannot control any hardware devices like printer or scanner with it.
So if your goal is to control the scanner from your web page with the help of any kind of extension than I think you cannot do this with Extension.
I have website link at which I have designed a html/javascript web app. I used iOS and Android app to create an app that encapsulates the web app.
Is there a way to block access to the website link and only allow access to the website link only thru the native apps calling the link.
In short safari, IE, Chrome must not be able to access the link, but the iPhone & Android app should be able to access it.
Is there some way to tell that the app is accessing the site and not the phone or pc browsers.
I am sure there a number of ways to implement this.
Thanks,
It depends on how is the web app implemented. Since native Web Views are pretty much the wrapper for the standard browser (Safari/Chrome), you will find it tough to filter it based on that.
What you can do, however, is to add an extra GET variable (for ex. &ref=youruniquecodehere) or a custom User-Agent, based on which you will be able to identify, whether your application authorized the request (with a proper access code) or if it's a generic request using browser.
However, both of these options can still be bypassed if researched, although it'd require slightly more time. Not sure whether a solution that would work in 100% of cases exists.
Hope that helps, please correct me if I'm wrong.
Using Dart lang, I've generated an application that stores several list of objects. I'm very happy with the result, congrats to Dart Team, but I have a question:
If I store several data using Chrome, is there any way to read this info from other web browser, i.e. Firefox.
That's why the user works with several web browsers in the same machine, he/she doesn't care which browser is open at that time, he/she wants to use the application in the current opened web browser.
Browsers can't access each other's data directly, but, given your diagram, it looks like IndexedDB is on the shared server and not in the particular browser so I can't see the problem.
If you have your database running on local server and it is accessible only with Dartium and for some reason you don't want or can't compile the browser part to JS(with dart2js) or do something else to make it accessible from the browsers without DartVM. then I can think of 3 ways how to perform browser to browser data transfer without the server(on which application is hosted):
With HTML5 Drag and Drop between browser windows.
Creating WebRTC client\server and transferring the data this way.
Using remote server and simple authentication with Gmail,Facebook etc. [the reasonable way]
I am creating a Cross browser Platform Web Application (HTML, JS, CSS), However I require a strong database storage that I can query on the client using JS. Web SQL/SQLite seems to be the best way to go BUT there is no support for it in IE. Does anyone know of any other querable client storage out there. or a working implementation of embedding SQLite "like" functions into the browser.
Thanks
The Web Storage API is available in all major browsers including mobile and desktop. I haven't used it before, but from my research I can tell that it doesn't use SQL queries. It seems to be the best option, even so I would recommend still using a fallback for browser that won't support the API (for example anything before IE8).
Hope this works out for you!
There is usually a limit of 5MB on localStorage on browsers, including iPhone's Safari.
Since PhoneGap has the access higher security privileges including access to other storage mechanisms on the device, in theory they should be able to eliminate the limit of 5MB.
For example, it should be able to get around the usual restrictions by storing the data on a file, etc while keeping the API compatible with localStorage javascript object.
Is this done? Or is PhoneGap limited to the same 5MB?
PhoneGap doesn't do anything out of the ordinary to extend the default limits. On Android, I get 2.5M characters in localStorage (Strings in JavaScript are UTF-16).
You can find default limits for most browsers here: http://dev-test.nemikor.com/web-storage/support-test/
This was helpful in understanding the limitations, and I used the code to create a simplified test PhoneGap app.
PhoneGap has File API that should not be affected by browser local storage limits but don't know if there exist any abstraction to make it behave as HTML5 local storage "backend".
If you want to store a large amount of data you should not do that in localStorage, there are databases and files for that kind of need. localStorage is a key-value datastore, it's use is limited and it should not be "hacked" to fit all needs.
Localstorage is something which is provided by the browser.
Localstorage is not something which is available on a device, either a mobile phone or a desktop, that is leveraged by a browser.
Since it is something which the browser provides there is no way, we can change/increase it using Phonegap since your Phonegap app runs inside the browser.
If you want more storage space, you can use a technique which Phonegap can access like a file storage or SQlLite.