Deployed Hello World – Installing Seaside and Squeak/Pharo Basics

Table of Contents:

Time to install Seaside. If you go to Seaside Download page (and click on the Seaside for Pharo Download link), you’ll see that there are several options. The easiest one is the Seaside One-click Experience — as I mentioned in the last post, this comes with a VM for your operating system, sources, and an image that comes with Seaside installed, and a web server started and ready to go as soon as you open up Pharo. This is the option you should go with — click on the latest one (at the time of this writing, it’s Seaside One-Click Experience 3.0.3).

Where should I unzip the download file? Squeak/Pharo is self-contained, so it doesn’t matter where you install it, it’s not going to make any Windows Registry entries or anything like that. I usually place it in C:\Pharo on Windows, or in my user directory on Linux.

To Launch Seaside: (after unzipping it into a Pharo folder) click on the folder, then on Seaside.app, then on Contents, then on the folder appropriate to your operating system, then on the executable.

If the VM is in Contents\Windows\, where is the image that I’ll be launching? The image lives in Contents\Resources. The default one that launches when you double-click on the executable is Contents\Resources\Seaside.image.

Go ahead and double-click on the executable and open Pharo. (On Windows, you will likely be prompted by the OS to permit the application to open a port — that’s the web server starting up). You will see three things — a server control panel, conveniently started for you, a code browser window, and what looks like a text file but is actually a full-fledged Workspace in which you can execute code (more on those later).

Where is the menu bar? File, Edit, Windows, Help, etc? Squeak/Pharo does not have the traditional menu bar running across the top that you see on most applications on Windows, Linux or Mac. It’s kind of like Emacs in that it tries to be its own universe (although even Emacs has menu bars on most latest versions). However, what you do have is the World Menu — click on any empty spot within the Squeak window (the squeak “desktop”, if you will), that is, anywhere not on the code browser or workspace, and you will see a popup menu titled “World”. This is essentially your menu bar, and contains the items you’d expect, Help and Windows commands, preferences, and so on.

Now the vi/Emacs question – how do I save and exit? Easy enough – click on an empty space on the Squeak desktop to bring up the World Menu >, then Save or Save and quit.

Wait, if I hit World Menu > Save, and then World Menu > Quit, why does it ask me if I want to exit without saving? Didn’t I just save? Yes, you did just save, so everything’s ok. It’s just being extra paranoid. If this disturbs you, then use the ‘Save and quit’ option to do both in one step, and then it won’t prompt you with that question.

When I click on the X icon to Close Window and exit, why does the prompt say ‘Quit Croquet without saving’, instead of Quit Pharo? That’s minor bug in the current release that I’m sure is left over from merging some of the code from Croquet into Pharo, ignore it. Actually, the Croquet Project is a fascinating VR/realtime collaboration project that’s implemented in Squeak, and is worth checking out.

OK, so how do I edit code? The last basic thing you need to know is how to actually edit code from within Pharo. Click over to the code browser window (it’ll say WACounter on the title bar — that’s the name of the class it’s browsing). Now click anywhere on the code and add an extra space or a return somewhere, just to have edited it. (Btw, see how the upper right corner of the code window turns orange? That’s how you know this method has been modified). Now, to save edited code, press Alt-S (I think it’s Cmd-S on Mac). (Why does Squeak use Alt-S instead of the more traditional Ctrl-S to save a window/buffer? I’m not entirely sure, but you can change this behavior in preferences (switch how Squeak handles Alt and Ctrl keys) to be more familiar for Windows/Linux users — I’ll explain how in the next post).

When you hit Alt-S (Squeak documentation will refer to this as Meta-S (Emacs users will find this familiar), so as to be consistent across operating systems), an Information Required prompt will pop up and ask for your name. Why does it do this? Because all code edits get saved in a version log (you can see this by clicking on the Versions button above the code editing area), and entering your name allows you to identify the code edits as yours. (When you start using source control tools like Monticello, this name will be used to sign your code changes). Think of it as the @author tag in the JavaDoc tool.

Important note: Meta-S just saves the code changes to a single method within the live image, it does not save the image itself. You still have to go World Menu > Save to save the whole image to disk, before you exit (or commit your changes to a version control system, once you start using one).

How do I open another code browser window? Go to World Menu > System Browser and that opens up a code browser window (incidentally, you can switch between the open windows in Squeak by pressing Meta-Left or Meta-Right keys, kind of like switching tabs in Eclipse or Firefox).

Ok, you now know enough to be dangerous to write code. Next up, a quick note on customization, and the on to the Hello World web app in Seaside.

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4 thoughts on “Deployed Hello World – Installing Seaside and Squeak/Pharo Basics

  1. Pingback: Deployed Hello World – Installing Seaside and Squeak Basics
  2. Awesome, keep this rolling please! You’re giving me the encouragement (through some example) I need to jump into ST. Will MongoDB be brought in for persistence/storage ? (apologies if the terminology is out – complete and possibly un-help-able newb!)

    Cheers, keep up the good work

  3. Great tutorial. This goes a long way in helping my move my consulting practice entirely to Smalltalk. I’m tired of struggling with other environments and want to commit entirely to Smalltalk. I’ve worked on and off with Squeak since 1998. Keep up the good work.

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