I have a PWA designed in Ionic and we are using it to take pictures. However the requirements is that it needs to work offline so we are storing these pictures in IndexDB.
However I have been unable to track down how much storage we will have access to in IndexDB and am concerned it will only be around 50MB or so. The the customer potentially wants to store 100 images or more offline and when it gets back to wifi it will start sending up to a remote API.
Is there any information on storage capability for indexDB when a PWA is run on a mobile device either IOS or Android?
I have seen some posts that but mainly talk about storage of the javascript files where this is actual data captured while the app is running.
NOTE: Individual images will be no more than 2-3MB each in size.
How to get data consumption of individual iOS application (i.e. if a device has 10 applications which consumes data, I want to know how much data each application consumes)
Short answer: you can't.
Long answer: all iOS applications are executed in a sandboxed environment, limiting the access that you have to data from another applications to avoid malicious behavior. The only way that you could obtain this information is if iOS had a public API that provided that information (it doesn't) or if the other applications published their information somewhere reachable from your application.
This is (a very simplified version of) the scenario with which I am faced:
I have an existing web application which manages jobs. We are now purchasing a number of ios devices (iphones and ipads) and I need the web application to know which specific device (regardless of the user) is updating information through the web application (as well as getting the GPS co-ordinates, but I think I have that covered with the geolocation API).
I have control of all the devices, they will all come to me before being distributed and will return to me periodically, so I can modify/restrict etc., but I can't jailbreak.
I have no experience of ios, but if there is a way to do this without needing an app, that would be the best choice.
You can use HTML5 storage to create and save a GUID the first time user accesses your website and send it with subsequent requests.
I've seen differences of opinion across the web on this. It has been said that starting with iOS 5.1, local data storage for HTML5 content on the iPad is no longer guaranteed to be persistent, however on Apple's current Safari developer pages (https://developer.apple.com/technologies/safari/html5.html), offline persistence is suggested to be guaranteed.
Does anyone have any recent experience with this subject and able to comment on how reliable the database features of HTML5 are with Safari on iPad?
This will probably be enough information:
The w3c spec of localStorage is:
The second storage mechanism (note: localStorage) is designed for storage that spans multiple windows, and lasts beyond the current session. In particular, Web applications may wish to store megabytes of user data, such as entire user-authored documents or a user's mailbox, on the client side for performance reasons.
And on the Apple page:
Safari supports the latest HTML5 offline data storage features. Your application can store its information on the local machine using either a simple key/value-based data store, or a robust SQL database. The data is stored locally and persists across launches of Safari so your application doesn’t need a network connection to access the data, improving startup time and overall performance.
And searching Google (and Yahoo! because of some anti-google freaks) gives me:
In iOS 5.1 Apple have moved the location of localStorage files into a Caches folder which is subject to occasional clean up, at the behest of the OS, typically if space is short. It is likely that Apple have done this to stop localStorage being backed up to iCloud.
localStorage not accessible in IOS-6 Safari
I am not able to access localStorage in Safari (IPad with IOS-6).
For example, the following code is working fine in Windows on all browsers and on (iPad with iOS-5) but not in iOS-6:
localStorage.setItem("var","5");
alert(localStorage.getItem("var"));
Answer:
I was able to fix the issue by turning off private browsing on the iPad. I came across the solution from the reference : https://github.com/cloudhead/less.js/issues/312#issuecomment-2994845
Yes, Apple cleans up localstorage when the device is low on storage space. (I actually tested this and confirm it with a certainty).
I'm currently graduating at a small company which makes and sells accounting software.
My task during my graduation is to make a Mobile application which supports some functionality of this software.
For instance: making a report on site and uploading it to the server,logging hours worked, retrieving sales information etc..
I'm currently doing research on which platform I should deploy but I'm getting confused in what shape my application should be made.
I can't make a choice what I should recommend, Web app or Native app?
I need help making a recommendation:
Security is important. (we deal with confidential information)
Maintenance is very important. (they will have to support it in the future and have low resources available. (small company))
Development costs (I have no clue here.)
User experience (Because this is a business app, is a web app good enough?)
The business market here is currently very iOS (Apple) saturated (about 80%) but I do need to think of the future. (Android, WP7)
So What do u recommend with the given information, web or native? Do I need more information before making a decision / recommendation if so, what sort of information?
ps I think this question belongs on stackoverflow, if not please move it to the appropriate site.
For what you're looking to accomplish, I'd recommend taking the mobile web app route. Here's why:
Security is important. (we deal with confidential information)
You could make a case either way, but I feel that a mobile web app is better for security. Like Ganzolo said, it can have as much security as a typical web app. Also, since it doesn't store data on the device itself, you won't have to worry about a data breach in the event of a lost or stolen phone (assuming you're not using HTML5 offline storage).
Maintenance is very important. (they will have to support it in the future and have low resources available. (small company))
Mobile web apps have an advantage here. If you built native apps, you'd have to build and maintain separate apps for each platform. On the other hand, since one mobile web app reaches all platforms, you'd only ever have to maintain one app. Also, you won't have to update a mobile web app with each OS update, like you would with a native app. If you want to go one step further, you could even build a mobile web app with separate presentation layers for smartphones, tablet, and PCs (like this). That way, one mobile app would look different (yet native) on any device, but you'd only have to maintain one underlying application.
Development costs (I have no clue here.)
Depends on how many platforms you want to reach. If you're building for one platform, the costs are similar. If you're building for multiple platforms, mobile web apps are far cheaper. One mobile web app reaches all platforms, whereas you'd have to build a separate native app for each platform.
User experience (Because this is a business app, is a web app good enough?)
You'll get a better UI with a native app, but a mobile web app should be more than sufficient for most business apps. Use a good mobile framework (like jQuery Mobile), and you can build a mobile web app that looks and feels almost native.
The business market here is currently very iOS (Apple) saturated (about 80%) but I do need to think of the future. (Android, WP7)
Mobile web apps are a much safer choice for the future. Who knows what the mobile platform landscape will look like in 2 or 3 years? Maybe WP7 will be popular. Maybe some new OS will be popular. It changes so fast, there's no way to know. The only thing I do know is this: The web will still be popular. If you build a mobile web app, you insulate yourself from all future mobile OS battles.
I hope that helps.
My personal opinion would be to go for a web App :
• Security is important. (we deal with confidential information)
Sercurity in a web app cannot be worse than security in a regular website (like online banking)
• Maintenance is very important. (they will have to support it in the
future and have low resources available. (small company))
Maintenance is really easy for a web app since you can make updates without going through the process of submitting your app to the store and waiting.
• Development costs (I have no clue here.)
Development cost will be lower with a web app as you'll have 1 code for every phones (and most of them are using webkit which will be simplier)
• User experience (Because this is a business app, is a web app good
enough?)
It's hard to answer this question without knowing your project but for simple UI it can be good enough
• The business market here is currently very iOS (Apple) saturated
(about 80%) but I do need to think of the future. (Android, WP7)
Yes you need to think about the future that the most important because you can only do simple functionality in web apps. So if future requirement, will have more complex functionality then you'll have to move into native apps.
Hope I've been helpful
In my experience, web apps always tend to be sluggish on the UI front. I would always opt for a native app, if you don't have to support multiple platforms at once (iOS, Android, generic).
Security: Make your app connections over SSL
Maintenance: The only problem here is that you may have to wait 7 days for App Store approval for native apps
Development costs: Depends on who makes the app, shouldn't be too different.
UX: Defenitely native!
Multiplatform: As I said, for multi platform a web app is probably best
If you opt for a web app, make sure the user doesn't have the impression of "the app isn't doing anything" while loading stuff.