I have a few questions regarding daemons. Indeed, even the macos developer center has limited information resources.
I want to develop an application daemon that runs after system boot without login.
a) a Daemon; Is it a simple console application combined with a plist? Because there are almost no tutorials on daemon development related to Xcode. If there is a code sample reference, can you share it here?
b) Can daemons be downloaded from the app store? Because there must be a software that I can offer to everyone through the App Store. Is the installation automatic like other app store apps? If anyone has experience and can share it, I would be very grateful.
c) I am working on an API related to mirroring the screen to Android phone. Do you think a daemon has full access to WiFi/BLE and screen capture APIs?
I would be very happy to hear your suggestions.
I've made a launch daemon in the past, for the purpose of making a privileged helper tool with SMBless. I can share some of my experience.
A
a Daemon; Is it a simple console application combined with a plist? Because there are almost no tutorials on daemon development related to xcode. If there is a code sample reference, can you share it here?
Here are some resources that I found useful:
Woody's Cocoa: implement a privileged Helper. This article covers the low-level, step by step process of making a launch daemon and launching it as a privileged helper tool. If you have no need for privileged execution, the steps would be much the same, but without the SMJobBless parts.
SwiftAuthorizationSample which show cases SecureXPC (a framework for Swifty, Codable-based XPC communication) and Blessed (a framework for a Swifty, modern interface to SMJobBless and the AuthorizationServices framework). It handles a lot of the complexity from #1.
Apple's Daemons and Services Programming Guide
B
Can daemons be downloaded from the app store? Because there must be a software that I can offer to everyone through the app store. Is the installation automatic like other app store apps? If anyone has experience and can share it, I would be very grateful.
No. You would distribute them as part of an app, and make your app install them when required.
I am working on an api related to mirroring the screen to android phone. Do you think a daemon has full access to WiFi/BLE and screen capture APIs?
WiFi certainly, but I'm not sure about the screen capture APIs. One of the differences between launch agents and daemons (IIRC), is that only launch agents can connect to the window server, which I assume is necessary for the screen capture APIs.
From Technical Note TN2083 – Daemons and Agents:
Daemons
A daemon is a program that runs in the background as part of the overall system (that is, it is not tied to a particular user). A daemon cannot display any GUI; more specifically, it is not allowed to connect to the window server. A web server is the perfect example of a daemon.
...
Agents
An agent is a process that runs in the background on behalf of a particular user. Agents are useful because they can do things that daemons can't, like reliably access the user's home directory or connect to the window server. A calendar monitoring program is a good example of an agent because:
Related
Where can I find list of PWA features that are supported and under development for each browser?
This will greatly help to determine if I shall develop a native app or go directly for PWA. And also know upfront what to expect in the foreseeable future in terms of browser support so that I can enhance my app with newer features.
Thanks
Actually you can try
https://whatwebcando.today/
for test your browser first
Web App Manifest, and
Service Worker API
seem to be the key technologies to watch. Google's Progressive Web App Checklist mentions both of these technologies.
However, other technologies such as BeforeInstallPromptEvent, or PWA installation notifications, are explicitly discouraged by Mozilla Developer Network, MDN:
Do not use it [BeforeInstallPromptEvent] on production sites facing the Web
Also, as an aside, commercial incentives for PWA's appear to exist:
The Supreme Court signaled Apple could face a revived antitrust
lawsuit over its price control [...and 30% take] of the iPhone and
iPad App Store. -Fortune
Google indicates that a progressive web app, PWA, is:
Progressive - Works for every user, regardless of browser choice because it's built with progressive enhancement as a core tenet.
Responsive - Fits any form factor: desktop, mobile, tablet, or whatever is next. Connectivity independent - Enhanced with service
workers to work offline or on low-quality networks.
App-like - Feels like an app, because the app shell model separates the application functionality from application content .
Fresh - Always up-to-date thanks to the service worker update process.
Safe - Served via HTTPS to prevent snooping and to ensure content hasn't been tampered with.
Discoverable - Is identifiable as an "application" thanks to W3C manifest and service worker registration scope, allowing search
engines to find it.
Re-engageable - Makes re-engagement easy through features like push notifications.
Installable - Allows users to add apps they find most useful to their home screen without the hassle of an app store.
Linkable - Easily share the application via URL, does not require complex installation.
You can check this blog about the features of PWA. Also based from this documentation, Chrome, Opera and Firefox have all implemented support for service worker with Edge having positive public signals about interest in the feature. Safari briefly mentioned interest in it via one engineer's proposed five year plan. You can also check this related thread for more information.
I am new to ios development and doing development in ios4.0.1 and xcode 3.2.3. My application should capture other application's launch time and (close) end time. how can we do this? Any help will be appreciated.
Thanks
Pushpa
For apps in the app store, the answer is "You can't". The best way to think of other applications on iOS with respect to yours is: don't. You can't access their data, you can't see if they're running, you can't control them, and you can't change them. Apps are well and truly sand-boxed as a fundamental design decision in the current setup.
About the only thing you can do is trigger their launch with a suitably formatted system URL. If a Wikipedia application has registered the scheme wiki, you might be able to launch and communicate some simple data by having the system load the URL wiki://articleName, but that's the limit. You don't even know what application will be launched, only that one has the wiki handler.
Jail-broken iOS systems are a whole different matter, but I'm assuming you're not working on those.
Is there any good advice on uploading files to the device? I've seen many apps create a http server on 80 or 8080 to upload files. Does that mean I have to implement a server too?
Are there any 3rd-party libraries? (Preferably open-source and non-GPL)
EDIT: I am going to upgrade files in the app for specific devices in a corporate environment, so the ipad pulling files from a central server is also an alternative. But I would have to send messages to these ipads to tell them to fetch those files.
But I would have to send messages to
these ipads to tell them to fetch
those files.
Push Notification Programming Guide
Or mail with custom URL scheme for launching your application.
iOS Application Programming Guide - Implementing Custom URL Schemes
I assume what you want is a kind of automatic update. An app do something by order from server without user's manual operation.
I don't know enterprise-license specific feature of iOS. But I believe there's no such enterprise-specific APIs. And as I know, automatic update is almost impossible. Because,
There is no system-level support for automatic update. (yet?)
So messaging and fetching feature should be implemented in app.
But no app is guaranteed to run in background for long time.
And also user can turn off any app at any time.
There is no way to send message to an app which is not running.
Even you can send, there is no way to address each client form the server.
If your app is running, sending message or commanding them to fetch or do anything is just a simple work. The problem is there is no regular way to force them always keep alive. Even under situations like OS reboot or abnormal termination.
However there is an alternative. Just registering app as VOIP app like Skype. OS does not keep the app running too, but will monitor specific socket port, and will wake your app when the socket receives some message. For more details, see here: http://developer.apple.com/library/ios/documentation/iphone/conceptual/iphoneosprogrammingguide/BackgroundExecution/BackgroundExecution.html#//apple_ref/doc/uid/TP40007072-CH5-SW15
In AppStore, an app using VOIP for other purpose like automatic update will not be passed, but you have no need to concern about it.
And other way to send message to device without running app is push notification. This is a feature supported in system-level. But this is not designed to commanding app. This is designed to send textual message. So If your app is not running, the message will be displayed to user. However, you can guide the user to start the app by sending push notification.
As a final option, you can request some feature to Apple for enterprise environment. If your company is big enough to get an enterprise license, Apple will consider your feature request seriously.
If you decided to use VOIP method, I'm sorry I can't help you any more. I have no experience of implementing this kind of app. But it should not so hard.
However hard part is server. It definitely require custom server program which keeps TCP/IP connection. Regular HTTP server cannot be used. Because HTTP itself is designed as not to keep TCP/IP connection. You have to build this kind of server yourself from scratch. You'll have to handle lower level TCP/IP transmissions.
There are a few solutions(both of free/commercial) for this kind of server, but none of are popular because this kind of server regularly needs full customization. So there's nothing to re-use or share.
However I believe this is most suitable implementation for your app.
If you can satisfy automatic update only when the app is running, you can archive it by polling server status from the client periodically.
This is easy to implement because you can use regular HTTP servers for this. Client connect and download recent updates from central server periodically. If there is a new update, just fetch and do what you want. And the app is launched, just check the update at first. Prevent all operation until update applied.
This is regular way. Most of applications are built with this method. In this case, you have no need to implement server or hard thing.
However applying speed of update is depend on polling period.
(Edit)
I couldn't care about private APIs. Because your app is not for AppStore, so you can use private API's freely. (This is different thing with jail-breaking. There are so many hidden features by excluded from documentation) I don't know about private APIs, but it's possible there is some API which enable the support for keep-alive of the app.
However, this reverse engineering work is so painful unless you're born to hack.
You may try to use the following open-source in your project:
http://code.google.com/p/cocoahttpserver/
https://github.com/robin/cocoa-web-resource/wiki
Apple has some sample code on their website that details exactly what you're looking for:
http://developer.apple.com/library/mac/samplecode/CocoaHTTPServer/CocoaHTTPServer.zip
So you have a couple options:
You could distribute your app wirelessly within your organization and push new content out as app updates. Apple provides this option to their Enterprise Developers.
Wireless App Distribution
iPhone enables enterprises to securely host and wirelessly distribute in-house apps to employees over Wi-Fi and 3G. Apps can be updated without requiring users to connect to their computers. In-house apps can be hosted on any web server accessible to users. Users simply tap on a URL to install apps wirelessly without needing to connect to their computers.
The alternative is you configure the app to fetch the updated data. You describe adding an HTTP server to the iOS device, but there's no way the server can receive data when the app isn't running. Given your needs, it would probably work better to embed a web client in your app instead.
If I was in your shoes (and option #1 didn't work), I'd use ASIHTTPRequest to check with a server at launch/daily. If there are new updates, the app could then either prompt the user that there are new data files to download, or it could just silently download them in a background thread.
UPDATED: Perhaps I should have been more explicit about how to do #2. You can configure the download so it isn't interrupted when the user quits the app (you don't need to do a Voip hack). Check out the Completing a Finite Length Task in the Background section in the iOS Programming Guide.
There are http server sample codes from Apple and open source community such as cocoahttpserver TouchHTTPD.
You can upload file to the http server on iphone.
Here's a blog and screen-shots about running cocoahttpserver and upload file to iphone.
The Python CGIHTTPServer allows you to create a server in 0 lines of code:
jcomeau#intrepid:~/rentacoder/bin2txt$ python -m CGIHTTPServer
Serving HTTP on 0.0.0.0 port 8000 ...
Actually implementing a script to parse the input and save the file would take a little more effort.
[later]
OK, so forget about that, Apple doesn't allow it. See Local server on iPad for the iPad at least.
I want to run two app simultaneously, I am using jailbroken phone and dont want to upload that app to the app store.
Is there any way so that I can log phone call time, this can only be done if my "logging app" is running in background.
Please suggest me, how can I do this on jailbroken phone.
Some thing like:http://msdn.microsoft.com/en-us/library/ms884959.aspx (its for windows)
Is this actually a programming question, or are you asking for an app that logs call times?
Assuming the former, you would write a iPhone program that hooks into current phone conversations some way (private APIs? Not sure if this is indeed possible, just assuming.) You would then run your app via Backgrounder or some other wrapper that provided an interface for multiple applications to run at the same time. This usually comes at the cost of increase battery life, depending on how much CPU (and maybe memory?) the backgrounded app consumes.
Backgrounder is available via Cydia, I believe.
Need to include CoreTelephony, will solve the issue
I was trying to compare the three above mentioned platforms and what considerations one needs to think about when programming in order to create some kind of code base that could run on all three.
This is what I have collected for the iPhone - it would be great if somebody else could write something similar for the other two.
Only one application can run at any
given time. i.e. that is why the
SQLLite database is loaded as a file
into the app instead of as
traditionally having some kind of
server to connect to.
Only one fixed size window 480x320
pixels
Runs in a sandbox, when the app is
deployed a sandbox is created
"around" the app, the app can only
read/write files from within that
area. Also low-level access to the
phone is restricted.
Since a program can be stopped at
any time (see point 1) this needs to
be considered when designing the
app, at any time must the app be
able to write its current state to
disk so that it can resume later. If
this takes longer than five seconds
the app will be aborted.
128MB RAM, about half of that 64MB
is available to the app. There is
typicall 4GB storage (depends on
model), no virtual memory, if memory
is running out the app may be
aborted.
Edit: just to be clear, I am not after which platform/os is best for the developer, I am just interested in spec. comparison to know what can be expected if one has three target platforms and using native language for each (not web apps), what the memory and other considerations are.
Edit: removed language as its assumed that native language for the platform will be used.
There is an excellent article on Codeproject which would be of benefit to your question. Head on over here to read it.
Hope this helps,
Best regards,
Tom.
For Windows Mobile I want to add:
Windows Mobile in comparison to iPhone allows multiple applications to run at same time.
It comes with variable screen sizes and has different sdks (
Windows Mobile Professional for 'Windows Phones' (smartphones) with touchscreens and
Windows Mobile Standard for 'Windows Phones' with regular screens)
The framework which is generally used is .Net Compact Framework besides some people also prefer open-net which is a open source framework.
Unlike in iPhone, Windows Mobile has no private api's which means it gives more power to developers.
The memory size allowed for a program is 32 mb
You do not need a developer license for developing and shipping applications on windows mobile although windows mobile itself prompts you to avoid installing apllications which are from unknown publishers.( which is more interesting unlike in iPhone you need to have a license while you only want to debug your applcation on your device(not for the jailbroken devices.))
And for some bad things about windows mobile, see this link.
Thanks,
Madhup
I feel like the final list will be of little use, as all data points collected will differ substantially in content apart from your last one. Some corrections to your iPhone list:
1) Local databases such as SQLLite are"not traditionally" implemented as a server on other mobile platforms either (they also use various file-oriented DB's).
2) Very soon that single fixed size assumption may well be inaccurate.
3) The App is in a sandbox but can write to some areas outside of the sandbox via API calls (for instance, photo library or address book).
5) That number varies between 3Gs and 3G/2G/Touch (the older models have half the memory)
6) Monotouch is available, but I'm not sure there's anything that far along for Java based iPhone development. There's also a Flash compiler from Adobe.
Basically if you are thinking cross platform, memory/screen size/system access/common databases will all differ - so the whole thing boils down to language AND LIBRARIES. And that is where you really have an issue with a cross-platform approach, because the libraries are very different per system... in the end you MIGHT be able to share data structures and some pure data processing code across the platform binaries, with very different GUI code for each system. But is it really worth it to constrain the development of each client?
On a side-note Blackberry is Java-based, so it presents yet another hurdle for such an attempt.
If you really want to see what cross platform ends up looking like, take a look at the codebase for Waze - a cross-platform open source navigation app:
http://www.waze.com/wiki/index.php/Source_code
Client source for iPhone and Windows Mobile lives there.