I've already written some small Android Applications, most of them in one Activity and nearly no data that should be persistent on the device.
Now I'm writing an application that needs more Activities and I'm a bit puzzled about how to organize all this. My app will download some data parse it show it to the user and then show other activities depending on the data and the user interaction. Some of that data could be cached, some of it has to be downloaded every time. Some of that data should not be downloaded freshly at the moment the orientation changes, but it should on the moment the activity is created...
Another thing I'm confused about are things like a httpClient. I now for example create a new httpclient for every activity, the same thing for locationlisteners.
Are there books, a blogs or documentations with patterns, examples and advice on organizing larger apps build on android? Everything I found until now are get startet tutorials leaving me alone after 60 lines of code...
I would be very happy if some of you could provide some good resources.
Check out the Application Fundamentals if you haven't already. It's got a wealth of in-depth information. Then you can branch out to the more specific guides like Designing for Performance or Supporting Multiple Screens, which a large app would certainly have to deal with.
Also, here are some deeper specifics on Activity Design.
Google actually has a ton of awesome doc on this stuff.
I'd suggest taking a look at existing open-source Android applications and learn from how they solved the problems you are facing.
For instance, I learned quite a few tricks from reading Foursquare Android App source code. I'd highly recommend reading source-code like reading a tutorial/book.
Related
I have just starting learning Android development. I am familiar with the Java and Adobe Flex UI. I have basic design curiosity regarding the android development.
What could be the ideal design to develop the app. (Lets say, I have 4-6 different tab)
I have all the wire-frame available. which could be my starting point.
I wanted to use JSON and mongoDB for connectivity purpose ?
Is there any framework available for android development (MVC) ?
Generalized functionalists nice to have. eg. Email or updates for the application to notify.
I am currently going through the tutorial but thats not really helpful in terms of designing the whole application.
Please help me.
thanks,
I think you first just need to take some time and have a good read on Google's own sites.
http://developer.android.com/index.html
Another good place for tutorials is
http://www.vogella.com/articles/Android/
There is no ideal design. Your starting point, is the site above.
Communication between your app and a server is mostly done by JSON or XML. You can't directly access remote databases (Maybe you can with some tricks, but you don't want to.)
Android is a framework, and it is based on MVC.
No idea what you're even asking here.
Good luck and try to make any future questions a lot more specific to programming problems.
How the app works
Currently an app is in the works which utility is to explore activities in 5 regions. Each activity is represented as an JS object with a fair amount of properties. Activities can be viewed through different filters in their respective tab, for example categories or a map. Inside each main filter, there are options to filter on date, region, accessibility etc.
The challenge
There is a lot of JSON that needs to be stored on the device, and support is required for both iOS and android.
In the best case scenario the data needs to be in sync with the database, and all data needs to be available on the device. The app will need to be snappy for a good experience, this means that fetching data needs to be as fast as possible. Furthermore, filtering data needs to be as snappy as possible.
Viable solutions considered so far (which don't quite cut it yet)
MongloDB with the MongloDB Titanium Store adapter, silver bullet?
This approach at first seemed be the silver bullet. Although the project seems promising, it is maintained by one heroic hacker, and the project is in need of some documentation. I have inspected the source, and hacked my way through the API, but to no avail, console.log and jasmine tests won't cut it this time. More important still, it is not quite finished yet, and features compared to MongoDB are missing. A great project, I hope it will catch on more and be capable enough to assist desperate titanium developers in the future.
JSONDB, only for iOS
This app really needs to work on both platforms, iOS and android, so no reason for trying this. Moreover, JSONDB works within a single context only, which would be a serious concern as well.
Ti Filesystem and JSON.stringify + JSON.parse, not memory efficient
A viable solution for saving a small list of saved items, which is also a feature in the app. But in other posts issues over memory limits with the use of JSON methods have been noticed for android. Though this might not be the least of my problem, memory efficiency overal will be a huge problem. Never have I seen benchmarks for performance with file reading and writing for Titanium, so I am not sure how big of an impact reading and writing would be. Filtering big objects is a huge concern as well, underscore won't manage this kind of big data. Iterating big objects is a huge problem no matter what approach I will choose.
Big ass global object
Practically the same approach as a Filesystem, only keep it in a global. This has the same issues and is just a plain unethical practice.
SQLite, yuck
Highly document oriented JSON data to SQlite, it sounds worse than samsung galaxy fanboys. Any feedback on this?
Multiple files + SQLite to maintain + lazy load, unicorns and rainbows?
Desperate for a solution, I might be onto something in the course of writing this post. There are probably something 10-16 main categories which each 1 to 4 subcategories. Keep all the activities for a subcategory in it's own file, which is a quite slim JSON. Browsing through categories, each subcategory is rendered in it's own TableViewSection, each subcategory be appended independently to the table based on how much the user is scrolled down, effectively lazy loading the content. There is only one quite quick file read. Within this view adding more subfilters effects only the already loaded items, and iterating this items is reasonably affordable.
Updating the data is also quite effective, only files that are subject to change are updated. A SQLite database can maintain the dates of all activities which have a expiry date, it can dynamically build it's own JSON file for the upcoming seven days or month. This will make the calendar view quite smooth for most usage. Picking future dates will be a nightmare though.
Still the map is an issue...
If you have read all of this, thank you. If you have experience with something similar, or might be onto something, feel free to reply! I have to quit writing, quit coding and start sleeping.
Sorry for the crappy monglodb docs. I developed it for some internal projects and really wanted to share it with the community, but the lack of docs does make it hard to use. But great news I have docs now lol also slimmed down and cleaned up the source code. Hope it works better for you now. http://monglodb.com
I'm the original author of JSONDB and thought I'd drop in and provide an answer for anyone finding this question via Googlefu.
JSONDB is now deprecated software - it's been replaced by another project called SculeJS. SculeJS aims to provide a full featured NoSQL database written in pure JavaScript for use in Titanium, NodeJS, and web apps.
JSONDB was originally only available for use in iOS applications due to limitations in the way Ti native modules were built - the current versions of JSONDB and SculeJS are compatible with both iOS and Android apps.
In a lot of ways MongloDB and SculeJS are similar, where they diverge is in the way SculeJS has been engineered. SculeJS is intended more to provide powerful, generic data structures with a rich query layer rather than being a straight port of MongoDB. No insult to Monglo - it looks like great software, I just wanted to point out the difference in intent between the two projects.
As a side note - all pure JavaScript modules are limited to to a single execution context within Titanium applications.
For what you're building I think MongloDB, JSONDB, SculeJS and TaffyDB would all do the job, the details of the implementation would just be slightly different.
I was encountering the same problem. I had about 5mb's of data which I wanted to store with the app, and not let it download.
I finally ended up with an SQLite database, with high performance. It is not as bad as you think. It might not be a nice solution ,but for the lack of choice it is a very good one IMHO.
Just create a couple of tables, and functions to parse them to database, and the other way around, and I promise you, you will be happy.
DO NOT store the JSON in the database, but store the values appropriately.
I have experience in Java and good understanding of OOP. 2-3 weeks ago I decided to learn to make applications for Android.
The problem is that all the books I have gotten through aren't looking to me extensive enough. Most of the books are about 300-400 pages long and can't properly cover decent amount of aspects needed to understand all the fundamentals. I'm currently reading "pro Andorid 4" by Reto Meier and it's one of the most detailed resources on the Internet but still not enough.
I find the Android framework pretty complex. There are Activities, Intents, Services and other APIs. The Android dev guide on the official page is really brief and can't make a detailed coverage of the main components. And I find other resources not detailed enough, too. The usage and the properties of Intents aren't explaind well enough especially for the implicit ones with the Intent constants and the Uri object as a second parameter in the Intens constructor, etc. Also I can't find information for other aspects and usage for Context, Cursor and what some actions return after the execution of onActivityResult() method and so on.
For this periond I gained knowledge for some basic and trivial stuff, but I'm very confused when I have to implement some not so common features like taking pictures, using broadcast recievers and services
So my question is - Where can I find more comprehensive and in depth explanations of Android's inner components?
And also how much time did it take for you to fluently make Android applications and fully understand everything involved into the development?
Where can I find more comprehensive and in depth explanations of
Android's inner components?
The official Android documentation is very good. http://developer.android.com/guide/components/index.html
And also how much time did it take for you to fluently make Android
applications...
Depends on what do you understand by "fluently". Let's say that without copying Hello World, looking what was the Activity all about etc. about 2 weeks.
...and fully understand everything involved into the development?
There is no need to fully understand everything now. Don't worry. Later you will understand most of the useful concepts. At the beggining just try to make some app and use Google all the time. Most of the time you know more or less how to do 90% and you just read up these lasting 10% of which you have no idea yet.
First time posting and first time working on Android, so go easy if I am breaking any rules :)
Anyways, I just got into making an Android app and I'm trying to create a simple trivia game. I plan to have many questions (hopefully about 5000+ questions) made. No data manipulation made, just straight up reading the questions and presenting it to the user. I am now faced with the dilema in how to store the questions.
I have two choices:
1.) Bundle the questions with the app: Possibly store the information in SQLite. Originally, for demo purposes, I placed the questions in an XML file, but I quickly realized how inefficient it will be once the questions start piling up. First, I am concerned if opening up such a huge XML file would suck up Android's memory. Secondly, I am worried how large the app would be if it contains 5000+ questions. I read here about the pros of XML vs SQLite. In that example, the user has 70,000 entries so maybe my 5,000 questions would be enough?
OR
2.) Host the questions on a server: I believe the upside is the app wouldn't need to be bundled with a vast amount of questions and wouldn't need to worry about the logic of opening and assembling the questions. It would just hit a PHP page and depending on the parameters sent, the PHP page would return the questions in XML format. The downside is the user would need to be online (to retrieve the questions) in order to play the game and my server would need to be up and running 24/7.
Has anyone encountered this design issue of how and where to store vast amount of data in an Android app?
Thanks, any help would be much appreciated!
From a marketing perspective, I think the right approach is #1. Just looking at the top app list, it's filled with apps that work offline. I don't know why most people fail to mention this one important criteria when they talk about marketing apps... especially in Android, where lots of people don't have a data plan. Plus, a trivia app sounds like something someone would probably use during a commute in a train as opposed to something like Facebook Chat that they'd use when they're online.
From a technical perspective, storing 5000+ questions really won't take a huge amount of space. There's this app called "MyFitnessPal". It stores maybe over 30,000 foods in a SQlite database, with nutritional information. So don't overestimate how much space it will take.
The advantage of going with #2 is if the questions or answers change often, you might want to go with that approach.
I think that the best option for you is to store the questions in SQLite.This way the users can have access to your game even if they are offline,which is one of the important things as Hisoka mentioned. So I think you should try using SQLite.
I would like to create a custom open source information management application, that I could adapt to practical needs of a psychiatrist. (and also would really like to avoid inventing the wheel). Could someone advise me what would be a good way to start? I have some amateur programming experience (see below), but I have little experience with java and eclipse (which I have set up with Android SDK plugin on my linux PC).
What I would like to achieve is a simple app where I could relatively easily re-program/rearrange information presenting screens. I would like the major development stages to be something like:
Basic framework of the app is done Main information is added
through the programming environment
basic formatting (bold, color, lists) should be supported
I imagine this would be through HTML/CSS markup Hierarchical (not
too deep) screens with concise information about conditions,
treatments; easy, not too cumbersome navigation is a must.
Possibility to attach own notes from android device
on every piece of information (e.g. on medical condition, on medication,
list of differential diagnoses, etc)
A desktop application that allows for easy adding and editing
of the content
initially could be even sqlite manager or something similar
possibility for adding images,
possibility to add rating scales, which would calculate scores
maybe also possibility to print through some android print driver
* in essence I envision this as a sort of an integrated website with a relatively simple database behind it (sqlite?) running on android. My models would be epocrates and medscape apps, but the content would be more specific to everyday psychiatric practice. It would include aspects of psychological therapies as well.
In about a years time, I think, the content would be interesting enough to see whether the app should go on the market.
My (limited) experience:
I am a MD - a Psychiatrist. I have some amateur development experience (php, html, css, Perl, bash, sed, sql, Access and some time ago - AS/400). I would like to start an app that I could modify as I go - in order to have the most useful info at my fingertips, when I need it in my work. I have considered some databases (e.g. HandDB) but my experience with them is that you get very constricted with their user interface and this hinders fast information retrieval when you need it. Adding information can be clumsy as well.
Why I am asking for help here
Most of tasks above seem pretty standard. I imagine that people with lots of programming experience here, probably would be able to point me towards some information that would help me to get started.
Many thanks for considering this :)
Are you going to develop this app? Everything you mentioned can be easily done by reading the android documentation. Although if its you doing the coding i recommend buying a book
You will find a lot of samples and other support in the android doc
Printing can be also setup using Google Cloud print
If you want to open source your application you can always use google code.
You have asked a really broad question here. But i guess the above information is good to get you started.