Automation on the Mac

Automating tasks on the Mac is very useful for a wide variety of reasons. In this article we are going to look at the different technologies available for automating tasks.

TOOLS

Automator

The simplest way of achieving automation. Automator which is a built in application allows you to create task workflows by simply dragging in a set of predefined routines into a specified sequence. Let us explore how it works by creating a watermarking print plugin

Let us look at how we can create a print plugin that automatically adds a watermark to the pdf file.

  1. First get hold of an image that you will use as a watermark.
  2. Open Automator.
  3. Click on “New Document”
  4. Choose Print Plugin as the type of task to createScreen Shot 2018-03-21 at 11.58.26 AM
  5. From the left hand side drag the “Watermark PDF Documents” option. You will be able to locate this from the PDF library on the extreme right.1
  6. Add the image that will be used as a watermark. Customise the settings to your desired level. You may have to use trial and error till you get the desired output.
  7. Similarly drag the Move finder Items to the right. You will be able to locate this from the Files & Folders library.2
  8. Save the task as WatermarkCreator.
  9. Open a text file.
  10. Select File > Print
  11. Click on the PDF drop down in the print dialog.3.4
  12. Select the newly created task.
    3
  13. You have now successfully setup your own watermark creator.

Shell Scripting

For those coming from a Linux/Unix background this might be a familiar option. Very often users need to run a series of terminal commands repeatedly. While it is not difficult to do this, wouldn’t it be nice if we could write all the commands in a single file? Shell Scripts help users do just that.

To create a shell script:

  1. Open TextEdit
  2. Write the following code in there (We will write code to create a series of files and folders in our home folder for a user called admin):
    #! /bin/sh
    cd /Users/admin/
    if [ -d "/Users/admin/Applications/" ]; then
    echo "Applications Folder Exists"
    else
    mkdir Applications
    fi
    if [ -d "/Users/admin/Sites/" ]; then
    echo "Sites Folder Exists"
    else
    mkdir Sites
    fi
    if [ -d "/Users/admin/Developer/" ]; then
    echo "Developer Folder Exists"
    else
    mkdir Developer
    fi
    cd Developer
    if [ -d "/Users/admin/Developer/iOSProjects/" ]; then
    echo "iOSProjects Folder Exists"
    else
    mkdir iOSProjects
    fi
    if [ -d "/Users/admin/Developer/macOSProjects/" ]; then
    echo "macOSProjects Folder Exists"
    else
    mkdir macOSProjects
    fi
    
  3. Save the file with the name FolderCreator on the Desktop.
  4. Open the Terminal Application
  5. Let us make the script executable. To do that, run the commands:
    cd ~/Desktop
    chmod 777 FolderCreator
    
  6. Now run the command:
    ./FolderCreator

You have now easily created your own shell script. For more information about terminal commands you can read the following articles: Terminal Commands for OS X – BasicTerminal Commands for OS X – Part 2Terminal Commands – Part 3, & Configuring/Troubleshooting OS X Using Command Line

AppleScript

AppleScript is Apple’s proprietary scripting technology. It comes bundled as a part of macOS. To create AppleScript tasks we need to use the built in AppleScript editor.

Here is an example of a small AppleScript

tell application “Finder” to set the view for all Finder Windows as column view
tell application “Finder” to close every Finder Window
tell application “Safari”
open location “<a href="http://www.arunpatwardhan.com">http://www.arunpatwardhan.com</a>
open location “<a href="http://www.amaranthine.in/feedback">http://www.amaranthine.in/feedback</a>
open location “<a href="http://www.amaranthine.in/gallery">http://www.amaranthine.in/gallery</a>
end tell

Copy that block of commands in your AppleScript editor and see what comes up.

There are many more things that can be done with AppleScript. You can have popup windows asking users for commands, turn off the computer. Change the settings for different parts of the OS and for different applications. All this with commands written in a single file. All the user has to do is double click the file.

For more information about AppleScript visit Apple’s Developer site.

Launch Agents, Launch Daemons

NOTE: Scheduling Launch Agents/Launch Daemons improperly may leave your computer in an unusable state. Always test this on a computer that does not contain important data. If you are unsure, please consult someone with knowledge of the same before proceeding ahead.

Launch Agents/Launch Daemons allow you to schedule tasks which are to be performed at intervals. You can also use them to ensure that tasks are kept running and that the user does not have the possibility to quit them. To setup a launch daemon:

  1. First create a Plist file that looks like the one below. I have created a script called echoer and placed it in the /Users/admin/Applications folder where admin is the user.Screen Shot 2018-03-22 at 10.34.18 AM
  2. Place the file in the ~/Library/LaunchAgents folder. Name it in.amaranthine.demod.plist
  3. Run the command in terminal to load the Launch Agent.
    launchctl load ~/Library/LaunchAgent/in.amaranthine.demod.plist

That’s it you have just setup a simple launch agent which will ensure that your script runs every 6 seconds.

For more information or to create detailed Launch Agents/Launch Daemons visit:Creating Launch Agents & Launch Daemons

Login Items

An easy way to automatically load, Applications/Files/Folder, as soon as well login is to use Login Items. This is very easy to do.

  1. Open System Preferences > Users & Groups
  2. Switch to the Login Items tab.IMG_1560
  3. Click on the ‘+’ sign at the bottom to add new Applications. Let’s add Maps so that it launches as soon as we login. You should see it appear in the list.IMG_1561

That’s it. You have setup login items. You can repeat this process for as many applications as you wish.

Others

PHP, Perl, Python, Javascript, Swift allow you to create custom automated tasks and routines. These require knowledge of programming.

Choosing the right approach

Which one to choose depends on a lot of factors but we can break it down to 2:

  • You are a technically qualified person and understand things like programming, scripting and command line
  • You are an end user working either at home or in office.

End User

If you are an End user then you should really stick to Automator and Login Items. These are the ones that are the easiest to implement and least likely to cause any issues. You could venture and explore other options if you have a good understanding of them. Or you can ask the IT or Tech Support teams to help you with scripting and other technologies.

Tech Support or IT Person

Any of the tools mentioned above can be used by you. Make sure that you have a good command over the tools and are able to troubleshoot issues arising out of their usage.

Note: The programs/applications/tools and languages mentioned in this article may not cover all the available options. Also, anyone who uses or implements the items mentioned in the article does so at their own risk. The author does not take responsibility for any loss or damage that may arise from the use of the programs/applications/tools and languages mentioned above.

 

When to use Swift & when to use Objective-C?

Over the past few years I have received a number of questions with regards to Swift & Objective-C. Specifically related to the future of the 2. I will try to address those questions in the form of an FAQ.

Should I learn Swift or Objective-C?

This is a question that I get from developers new to iOS/macOS App Development. Ideally speaking, you should learn Swift. As that is going to become the main language for App development on Apple’s ecosystem. However, the reality is a little different. There are a large number of applications that are written in Objective-C. You are likely to encounter them at your workplace. You may also have to maintain, upgrade & improve those apps. In such a case, it makes sense to learn Objective-C too.

Can I mix Swift & Objective-C in the same project?

Yes! But remember that you should check for feature compatibility between the 2 languages. Adding Swift code to an Objective-C project may not be very beneficial as only those features that are compatible with Objective-C can be written in Swift.

Going the other way round is not a problem. You can read more about that here:Mixing Swift & Objective-C

Will Objective-C be deprecated in the future?

That is an interesting question. There is no formal announcement from Apple stating the Objective-C is going to be deprecated. However, one can expect more attention to be paid to Swift. That is where most of the newest techniques, tools & technologies are going to be available. Objective-C will keep running as it is as of now.

Can I mix Swift with other Programming Languages?

Swift can easily be mixed with Objective-C. If you wish to incorporate C++ or C code in your Swift Project then wrapping them in Objective-C code allows you to achieve this.

Apart from that Swift does support working with C code code. You can read about that here:Interacting with C APIs.

Swift does not provide interoperability support for any other languages as of now.

Which version of Swift should I use?

It is recommended that you use the latest available version of Swift. However, the actual version that you work on depends on many other factors like: compatibility with OS Versions, support & business related choices.

Why shouldn’t we just convert all our Objective-C code to Swift and keep things simple?

A very tempting proposition. However, practical realities prevent us from doing this. The process of converting from Objective-C to Swift is time consuming. Apart from having to convert the syntax, the code also needs to be optimised taking into account the new features that are available. This will mean extensive testing and quality assurance. Most companies will not invest their resources into this endeavour.

A better approach is to migrate to Swift gradually. Here are some ways to do this:

  1. If its a brand new product/app that you are creating, start it in Swift.
  2. Any new reusable code components that are being created should be done in Swift (they should be Objective-C compatible if you intend to use this code in Objective-C projects).
  3. If any part of a product is going to undergo heavy change, either due to a bug fix or a new feature. This is a good time to convert it into Swift.

A good example is how Apple is approaching the process of migrating to Swift. They are doing it component by component.

I have been developing apps in Objective-C for some time. I am able to create any reasonably complicated app now. If Objective-C hasn’t been deprecated then should I start making apps in Swift?

This is a choice that you have to make. It is recommended that new apps (at the very least) be made in Swift as that is the language that will undergo the maximum amount of changes & improvements in the future.

What do you suggest as a trainer?

Another question that I get very often. It depends on the situation. I would say learn both Swift & Objective-C. You can skip learning Objective-C if you are confident that you will not have to work with any projects written in that language.

If I am starting on a brand new project I would use Swift. But if its an Objective-C project I would stick to Objective-C.

Can Swift development only be done on macOS?

No! Swift development can also be done on Linux. However, iOS/macOS/tvOS/watchOS App Development can only be done on macOS through Xcode.

How should I migrate to Swift?

There are different approaches that one can use. It all depends on the situation and needs of your organisation. Here are some things that you can do:

  • Start development of brand new apps (from scratch) in Swift.
  • If you are creating a brand new library which will be used for future projects then go ahead with Swift.
  • If a major component of an existing app is going to be changed significantly then you can go ahead with Swift.

You can do all or some of the above. There may be other strategies too. You should also factor in the cost of migration from one language to another.