Android App to access locally stores files, PDF, HTML and video - android

We have a mobile workforce using Android Galaxy tabs and use the MobiControl MDM product to sync detailed briefing files to and from the devices on a constant basis.
Rather than having the user search through a sea of irrelevant briefs in order to find the one they want, and to provide a nicer more activity specific UI, I would like to create an app which allows a user to tap a client from a list and then show links to the relevant files plus custom content such as recent news and summaries of activity.
I started to create locally stored HTML files (saved on the internal sdcard) with the idea of creating an app to access them using webviewer but have ran into a few problems...
1) What is the best way to access files that are stored on the sdcard using webviewer? loadData? string?
2) Although the files will be stored in client specific folders, the file names will change on a ongoing basis and these ever changing file names should be the titles of the links to allow the user to identify what they need.
Still very much at the preliminary stages of thinking and r&d so suggestions on the best route to take to achieve my goal is very much appreciated.
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1) What is the best way to access files that are stored on the sdcard using webviewer? loadData? string?
loadUrl() should work.
BTW, your item "2)" is not a question.

Related

Delivering downloadable content to Android application in Unity (loading with Addressables)

I have a rhythm game that I am almost finished working on but have hit a bit of a snag. We have an in-app store where users can purchase additional "song packs" for money. These packs contain song files (text asset), song banner images (png) and the songs themselves (mp3). This data is stored on our server, and the Unity app communicates with the server after a successful purchase is made. The server script validates the purchase via the Google Play Purchasing API (with the purchase token) and then if its valid, downloads the zip file of the data and extracts it into the Unity app. This part is working great.
However, I seem to not understand in what format I need to have the content or where exactly to put it. Furthermore, my game makes use of Addressables tags to load data between scenes. This works, but I am not sure how exactly I would handle this for downloadable content. Can I create new addressable tags via the API at runtime? I want to be able to add additional downloadable content to the app without needing to update the base games Addressable information. Is this even possible?
My main questions are:
How do I deliver my downloadable content? Do I need to package it in some type of Asset Bundle? Would this keep the import settings like audio compression that I set in Unity?
What folder should I extract the downloaded content on Android? StreamingAssets?
Can I create Addressable tags at runtime? Is this possible and is this a good idea?
Thank you for the help!
I would rather only code one core URL where your app when it is started can find and download the Addressables content catalogue! This allows you to fully add and remove entire Addressables, groups, tags etc without ever needing to rebuild your app. You could e.g. give each of your root objects a certain label (the same for all) then you can basically load the catalog and show the user all existing tagged results without immediately loading them .. see LoadContentCatalogAsync
How do I deliver my downloadable content
You need to build your Addressables via the group window and then simply copy the entire content catalog (JSON and hash) and the resulting individual Addressables (usually one per group) onto your server where your app can access and download them.
This way you can basically even have two complete separate Unity projects, one for building the content, one for the actual app.
You only need to be sure that both projects have the same code base used by your addressables and that all required dependencies are either in the projects or within the Addressables.
See Loading from Multiple Projects

Android WebView: offline manifest vs local files

I'm developing a simple Android App where the user must fill in a very complex form, for which I believe it's much easier to use an HTML form than an Android Activity with tons of TextViews.
The data collected by the form must be sent to some remote database, and the application must be able to work offline.
I thought of two alternatives, the question is: which one would be better?
Let a WebView load a remote website with an offline manifest
Let a WebView load a local website in assets folder
My second question is related to the storage when offline, and once again I have two options, and I don't know which one is better:
Using the HTML5 local storage, and let HTML + javascript send data to the server when online again
Let my Android app catch the form data, and handle everything the Android way.
Any input will be very helpful. Thanks in advance.
Regarding the first question: depends on how often will you need to update your form. An online cached form can be updated quickly, while bundled pages are only updateable together with the app, and you will need to consider that both legacy and new clients can connect to your server at the same time (users will procrastinate updating).
Another aspect is portability. Do you envision an iOS version of your app, or perhaps a mobile site? If yes, then an HTML5 solution is definitely more portable. Also, debugging an app which is entirely HTML or entirely native is usually easier than a hybrid one -- you can stay within a single debugger.
Perhaps, one drawback of using HTML local storage inside WebView is that the data you save will be in a kind of a "black box" -- you will not be able to back it up easily.
[Added later] OK -- one drawback of putting your site into assets folder is that you'll have to use file: scheme in order to access it. This can lead to some cross-origin loading access related issues if you will try to mix your bundled content with content from the web. Check these WebView settings for example: setAllowFileAccessFromFileURLs, setAllowUniversalAccessFromFileURLs, setMixedContentMode.

Android: Metadata about file

I am developing a notepad app which can store simple text files and checklists. Currently I maintain a separate file (say info.txt) that maintains information about whether a given file is a simple text file or a checklist and based on that I render my UI (for either listing all files or opening a file) to show that file in my app. However I am not very happy with this approach because is slow and does not appear to scale well.
Is there a better way to add "metadata" (e.g. if it is a simple text or cheklist, tags, etc) about a file in android?
Any help will be greatly appreciated
There are several ways of storing persistent data in Android.
The way you are currently doing it is through the device storage, and you are quite right it would probably not scale well in addition to being directly accessible to the user meaning they could edit or delete your metadata.
Using SharedPreferences would be one way of storing the metadata which has the advantage of being completely hidden from the user, as well as being relatively easy to set up. The main disadvantages I can see are that it may not scale well if a user has a large number of files, and it is much more difficult to retrieve files with certain criteria, a certain tag for instance, as you mention in the comments.
The best way to store data that will scale well, be persistent, and let you run queries on the data would be an on device SQLite database. SQLite will usually have more overhead in terms of setup time, but is far more robust and featured than any of the other options besides perhaps network based storage, which based on the information you have given is probably not something you are interested in. Based on your problem the SQLite database is probably the way to go and has the bonus of being expandable in case you ever decide to add more information, or even store the files in the SQLite database.

Add and load images, videos and pdfs from a raw folder or an SDCard Android Tablet design?

Good day, I have a requirement to create a kind of book app with pdfs, images and videos worth up to 10gb and more on a tablet locally. Now there is no intention to sell it on the android market or any other store, its completely in house, so i think issue with apk size has been clarified. What am asking is, where is the best place to put all this contents so that i can readily load them up and use them accordingly?
Should i be using the raw folder and create sub-folders for each images, videos and pdfs?
Should i create folders on an sdcard(assuming there is one in place)? or
Please if you have any other solution or ideas on how to implement this, I would gladly like to hear this. Thanks for your responses in advance.
P.S by the way, since its a tablet specific app, is there any need to have a multi-pane layout fragment or ii can just use all the space. thank you
I suppose you can use a RAW folder, but it would also make the APK size huge from what I understand because all the files in the RAW folder need to be packaged with the application.
From what I've seen in the past, most applications, actually most games, that have lots of extra data will download the additional data on first launch. Basically:
The application launches
It checks whether or not you have all the additional data (Books, pdfs, images)
If not, it starts downloading that data to the SDCARD.
It may not make sense in your situation, but doing it this way gives you more finite control over how much data needs to be downloaded. If function A only requires package A of additional data, then you only need to download package A, you don't need to download everything. Or perhaps you could let the user choose what packages of additional data they want to download, which would also save bandwidth, time and resources.

Is XML a good way to organize App data and keep it up to date on the Market?

this should be an easy one for whoever published Android Apps before...
Here is my situation:
I'm trying to develop a "city guide" app and I was wondering if my idea of working with .XML files to structure my data (the client provided a .PDF file with pictures, address, tel. no, websites, opening hours of the different destinations) is the best way to go.
I was hoping to be able to write this app as an "interpreter" for this type of .XML and then easily include other cities or destinations in a city by updating that input XML file.
So this is not a technical question, I know how to pull this off, the question is if this is a good way to go? How do you keep an app easily up to date? Would a altered XML trigger a Market wide update notification ?
My research lead me to believe that this is a comfortable way to update a published Android Market app (prior to this inquiry I consulted:
http://developer.android.com/guide/publishing/publishing.html
All helpful hints and suggestions will be greatly appreciated.
Regards,
Veo.
Once I developed such kind of an app that had to contain the whole information in itself. I structured it in SQLite database that I was shipping along with the application. The file was not directly readable (or at least easy to read) from the assets folder, but every time when the file was altered I copied the sqlite file to the application storage and used it as ordinary application database. The cool thing is that this way I did not have to pay for the parsing of xml every time the application ran.
Several notes here:
My database grew too big and I had to split it in files of 1MB, because this is the limit for a file in the asset folder. For more info see here:
The database update mechanism with the database version still worked well.
When you create the database manually you need to take into account that Android expects one system table to exist in it (it is automatically created if the database is created in Android code). Basically see this answer here for more info on that.

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