TweetFollow Us on Twitter

June 95 - MPW TIPS AND TRICKS

MPW TIPS AND TRICKS

Building a Better (Development) Environment

TIM MARONEY

[IMAGE 063-065_MPW_Tips_html1.GIF]


The days of the solitary hacker are long past. While this reclusive species is still spotted in the wildernesses of academia and shareware, today's commercial engineers roam the virtual plains in herds, overcoming the incessant problems of bloated software projects by sheer force of numbers.

Like all human groups, software teams are tied together by a shared language and environment. On the Macintosh, this common ground often contains a set of MPW scripts and tools. While most developers prefer the faster compilers offered by third-party vendors, the scripting and source control capabilities of MPW make it an indispensable workhorse in team software projects. It even serves as the cornerstone of many cross-platform efforts involving both the Mac OS and that other operating system.

Following a few simple principles will greatly reduce headaches resulting from maintaining a team's MPW configuration. These guidelines may seem obvious, but I have yet to see a project that followed all of them.

ENGINEERS ARE USERS, TOO
While we may be accustomed these days to thinking of a user interface as a sequence of pictures, a build environment in MPW is as much a user interface as any other software system. Like all such projects, designing it naively invites the wrath of your users -- in this case, the engineers on your team. And unlike most users, they have your direct telephone number and know where you park your car!

The primary principle of user interface design is to stop thinking "I want to make the best X ever," whether X is a text engine, file system, image processor, build environment, or gorgonzola sandwich. That narrow form of thinking leads to excellent solutions to technical problems but systems that are difficult to use, because the model of the problem adopted by an engineer is likely to be different from that applied by an end user. For instance, to an image processing expert, rotating an image is a problem of accurate and rapid approximation across a grid, but to a scanner operator, the problem is one of deciding when to rotate, whether to do it automatically, whether to do it before or after other operations, and so forth. A technically superb rotation algorithm may completely fail to meet the requirements of the operator in a print shop if it wasn't originally designed with that environment in mind.

Balance technical problem solving by thinking through in detail how the system will be used to accomplish specific tasks. Spell out particular scenarios and make sure your solutions work in them. Otherwise, they probably won't. So, to keep the needs of your various users in mind, you need to consider not only a normal build, but auxiliary tasks such as the following:

  • installing and updating the system
  • incorporating scripts from other sources
  • giving MPW commands by hand
  • personalizing the configuration
  • maintaining a synchronized environment among all users
  • archiving the environment for reproducing builds
  • working from home over Apple Remote Access, and other ways of working remotely
  • troubleshooting scripts and tools

Never assume that smart people make fewer errors. A rule of thumb is that the number of errors made is proportional to the number of possible errors, not to the skill of the user. Error prevention should be one of your guiding principles in any system design. For instance, don't require three commands in a particular order to complete a build; a single build should be a single command. If you have user interface design staff, get them involved with the development environment; their familiarity with principles such as error prevention and nonmodality could be very helpful.

Most of all, talk to your users. Ask them what they need and what their problems are. Sometimes their suggestions will be ones you can use directly; more often they won't hold up to scrutiny as actual designs, but they always indicate a legitimate area of concern that you'll need to address. Design your system on paper first, and have your users review your drafts. This time will pay off later in increased productivity.

Many of the principles of modern software design were originally developed for traditional command-line systems. See The Elements of Friendly Software Design: The New Edition by Paul Heckel (Alameda: Sybex, 1991). *

CHECK IN THE SYSTEM
An obvious, but flawed, approach to organizing a system of tools and scripts is to put them all on a server where everyone can reach them. Each engineer is responsible for synchronizing his or her local configuration with the latest files on the server, and anyone can improve the scripts in their copious free time. In addition, everyone can customize their own system as much as they like.

In practice this simple scheme wastes the time of everyone on the team, because no one ever has the same configuration as anyone else. A typical frustrating conversation under this system would be:

I can't build the SuperWidgets library. Does it build for you?

Sure! Maybe you didn't get the new SourceGrinder script?

No, I got that yesterday, after I couldn't build Pat's latest brilliant changes to WhizzySnork. Let's take a look at your copy of the MungePrefix tool.

Hmmm. It seems to match yours. Gee, I don't know what the problem could be. Let's both do a complete reinstall and try again.

(Repeat until hysteria ensues.)

The solution to the problem of synchronization is to keep the build system itself under source control. When people run into problems, they'll make sure that they've checked out the current scripts and tools as well as the current source files,before they bother you about it. If they don't, they'll look silly. Since that will probably bring back unpleasant memories from the playground, they'll try harder next time.

For complex projects, you'll probably want to institute a regular build process with versioning and source archiving. When you archive the sources for a build, don't forget to archive a matchingrevision of the development environment! You may need to reproduce that build in the future, for which you'll need the source code and the exact build system.

In some larger projects, the development environment may be maintained by a group separate from the programmers who use the system. In that case, it may not be practical to archive the environment as part of a project build. The environment group needs to archive the system with named versions, and the project team needs to always build with respect to a named version of the environment. The project team also needs to record in its release notes which version of the development environment was used for each archived build. This allows the build to be reproduced from the two archives.

HAVE AN INSTALLED COPY HANDY
Bootstrapping an MPW configuration for a new engineer can be painful. There is a chicken-and-egg problem with any script-based installation of an MPW build system. The scripts you want to use for installation are checked in, but how does the first-timer get to them? You can write out careful step-by-step instructions, but few engineers can resist the temptation to improvise. You'll wind up doing it for them after all when they fail.

Instead, keep an up-to-date copy of a preconfigured MPW on a convenient server. The new user simply copies the entire MPW folder from the server to the local disk (remember those licensing restrictions,though!), edits the configuration file, and is ready to run.

THE DREADED USERSTARTUP*PERSONAL FILE
It's perfectly clear to the development environment designer that the user needs to type his or her name where it says

Set MyName "Your Name Here"

but no one ever seems to fill in the blanks correctly without hand-holding.

It may be worth your while to write a mini-application that sets up the personal configuration file in the MPW folder. An hour or two creating a setup application witha nice, clear modeless dialog will pay for itself a few newhires down the road. More simply, you can use MPW's Request, GetFileName, and GetListItem commands in a setup script -- but a single dialog is friendlier.

This application or script should also be stored on the server where you have the preconfigured MPW folder. With a little clever scripting, you can easily arrange for the application to be run automagically if the personal configuration file hasn't yet been set up.

There are a few kinds of setup that can be done programmatically. For instance, if a script needs to know the monitor size, don't ask users to type it in themselves; an MPW tool can look at the graphics device list and figure it out by itself.

ESCHEW CLEVERNESS
One of the best programming tips I ever got was from an introductory LISP text I read a few centuries ago as an undergraduate. It warned against cleverness in coding. On the surface this would appear to be stupidadvice. Isn't cleverness a requirement for programming? The problem is that when our own code strikes us as clever, it usually involves some trick or back door that's both fragile and hard to understand, not only for the next poor sap who inherits the code, but maybe for ourselves a month or three from now. Yet these clever tricks are rewarding. Not only does a trick resolve a sticky problem in one swell foop, but it reinforces our belief in our own intelligence and resourcefulness.

LISP, being inherently weird, lends itself to clever solutions. So does object-oriented programming. (I'll spare you the name of a program that buries its resolution of conflicting filenames -- dialogs and all -- deep in the bowels of a general-purpose string class.) Scripting languages such as those of MPW andcsh also encourage cleverness. Remember the scripts to accelerate launching in last issue's MPW Tips and Tricks? The form in which they were passed to me used a very clever method of signaling a cold boot: it aliased the built- in End command to Quit, bypassing the state-saving code in the Quit script. Needless to say, the potential for side effects was enormous, but no doubt someone enjoyed thinking of it! I changed the cold boot sequence to write an empty file called DontSaveState in the MPW folder, and the Quit script to detect and remove this file. It takes perhaps a tenth of a second longer, but it's comprehensible and free from harmful side effects.

KEEP IT SIMPLE, STUPID
Another common class of difficulties results from redesigning the basis of MPW. It can be tempting to make big changes to the system, such as by changing the default value of a built-in variable like Exit, or permanently blanking variables like CIncludes and RIncludes to prevent conflicts with local headers.

The problem is that this turns a multifunction system into a single-function system, making MPW useful solely for the build tasks you've planned. Scripts from other sources won't work anymore, and the existing techniques and skills of people on the team may become hard for them to apply in the oddly mutated environment. Getting rid of RIncludes might make some part of your build sequence easier to manage, but what happens when an engineer wants to DeRez something by hand?

The solution is to avoid changing the underpinnings of the MPW Shell. If you need to add variables, add them as new variables -- don't mess with the old ones. Don't install patches that let you add whizzy graphical menus and floating windows if they interfere with the ordinary AddMenu and Open commands. When you do need to change something, change it only in the scope of the script where it's needed.

Among other reasons, you may someday need to have more than one build system installed. Suppose your company is acquired by the Gizmonics Institute and they have their own MPW configuration. Would you rather throw away yours and try to figure out how to shoehorn your source code into their system, or be able to run them both in the same MPW Shell? Or suppose (and I admit this is pretty unlikely) you start talking with the weirdos down the hall instead of just snickering about them behind their backs. Before you know it, you'll be drinking beer together and trying to integrate your build systems. Don't laugh; it happens.

THE JOY OF THEFT -- SHARE AND ENJOY
There are various sources for useful MPW scripts. Instead of trying to do it all yourself, you can impress your manager by ripping off scripts from CDs, computer networks, friends, and so forth. Sometimes even magazines have good stuff.

Apple already distributes quite a few useful scripts, such as those in the folder called DTS MPW Goodies on this issue's CD. Posting a note on a Usenet newsgroup may get you just the script you wanted in a matter of hours or days (even though you could have done it better yourself, of course).

Remember to share a little of your own work to balance the karmic load. This is the philosophy of UNIX®, and unfortunately it's better developed in that culture than in ours. Don't forget the others in the virtual herd!


TIM MARONEY has been tempered in the forge of computer networks, acquiring a rough, cast-iron finish that's often mistaken for obnoxiousness. His favorite animal name is "Kittens," his favorite food is anything dead, and his favorite new game involves building globe-spanning conspiracies out of overpriced trading cards. Tim supplements his seven-figure earnings from writing for magazines by developing software for Apple. *

Thanks to Shad Ahmad, Dave Evans, Arnaud Gourdol, and Eleanor the Wonder Gerbil for reviewing this column. *

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Macs Fan Control 1.4.4.0 - Monitor and c...
Macs Fan Control allows you to monitor and control almost any aspect of your computer's fans, with support for controlling fan speed, temperature sensors pane, menu-bar icon, and autostart with... Read more
calibre 2.69.0 - Complete e-book library...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital librarian... Read more
Evernote 6.9.1 - Create searchable notes...
Evernote allows you to easily capture information in any environment using whatever device or platform you find most convenient, and makes this information accessible and searchable at anytime, from... Read more
jAlbum Pro 13.5 - Organize your digital...
jAlbum Pro has all the features you love in jAlbum, but comes with a commercial license. You can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly... Read more
jAlbum 13.5 - Create custom photo galler...
With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly, with pro results - Simply drag and drop photos into groups, choose a design... Read more
Google Chrome 53.0.2785.143 - Modern and...
Google Chrome is a Web browser by Google, created to be a modern platform for Web pages and applications. It utilizes very fast loading of Web pages and has a V8 engine, which is a custom built... Read more
Chromium 53.0.2785.143 - Fast and stable...
Chromium is an open-source browser project that aims to build a safer, faster, and more stable way for all Internet users to experience the web. Version 53.0.2785.143: [Security Fix] High CVE-2016-... Read more
QuickBooks 2015 16.1.7.1524 R8 - Financi...
Save 20% on QuickBooks Pro for Mac today through this special discount link QuickBooks 2015 helps you manage your business easily and efficiently. Organize your finances all in one place, track... Read more
Sierra Cache Cleaner 11.0.1 - Clear cach...
Sierra Cache Cleaner is an award-winning general purpose tool for macOS X. SCC makes system maintenance simple with an easy point-and-click interface to many macOS X functions. Novice and expert... Read more
Default Folder X 5.0.7 - Enhances Open a...
Default Folder X attaches a toolbar to the right side of the Open and Save dialogs in any OS X-native application. The toolbar gives you fast access to various folders and commands. You just click on... Read more

Pumped BMX 3: Beginner tips and tricks
There’s a whole lot more to Pumped BMX 3 than meets the eye. Your goal is to perform a wide array of sweet flips and tricks, but that’s easier said than done. It takes well practiced timing and coordination, and the game doesn’t really explain that... | Read more »
Cybird’s latest release - BFB Champions...
Launched in the UK in early September, BFB Champions’ newest update is loaded with great new features, and looks set to outshine the original version by taking it out of soft launch and giving it a new lease of life. | Read more »
3 apps to boost your focus
As someone who works from home, my workspace is a minefield of distraction. Cats, tasty snacks, the wind blowing past my window, that cleaning that I suddenly can’t put off any longer. If I let distraction takes its course, I find that soon half... | Read more »
Pumped BMX 3 (Games)
Pumped BMX 3 1.0 Device: iOS Universal Category: Games Price: $3.99, Version: 1.0 (iTunes) Description: The final instalment of the smash hit #1 rated BMX game is here! Following on from the insane success of Pumped BMX 2, Pumped 3... | Read more »
4 games like Burly Men at Sea to inspire...
Burly Men at Sea is out today and it looks a treat. It tells the tale of three Scandinavian fishermen who leave the humdrum of their daily lives to go exploring. It’s a beautiful folksy story that unfurls as you interact with the environment... | Read more »
3 reasons you need to play Kingdom: New...
Developed by a tag team of indie developers - Thomas "Noio" van den Berg and Marco "Licorice" Bancale - Kingdom is a vibrant medieval fantasy adventure that casts players as a king or queen who must expand their empire by exploring the vasts lands... | Read more »
JoyCity have launched a brand new King o...
Great news for all of you Game of Dice fans out there - JoyCity have just released a brand new limited edition pack with a really cool twist. The premise of Game of Dice is fairly straightforward, asking you to roll dice to navigate your way around... | Read more »
Burly Men at Sea (Games)
Burly Men at Sea 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Burly Men at Sea is a folktale about a trio of large, bearded fishermen who step away from the ordinary to seek adventure. | Read more »
3 tips for catching the gnarliest waves...
Like a wave breaking on the shore, Tidal Rider swept its way onto the App Store charts this week settling firmly in the top 10. It’s a one-touch high score-chaser in which you pull surfing stunts while dodging seagulls and collecting coins. The... | Read more »
The beginner's guide to destroying...
Age of Heroes: Conquest is 5th Planet Games’ all new turn-based multiplayer RPG, full of fantasy exploration, guild building, and treasure hunting. It’s pretty user-friendly as far as these games go, but when you really get down to it, you’ll find... | Read more »

Price Scanner via MacPrices.net

CAZE Annouces New Zero 5 Case for Jet Black i...
Hong Kong basd CAZE has announced Zero 5 case for iPhone 7/ 7 Plus, one of the world’s thinnest clear hard cases, measuring just 0.5 millimeters. CAZE has been producing and improving the Zero 5... Read more
Nest Egg Inventory App for iOS Offers Conven...
Campbell, California based Winprogger LLC has announced the release and immediate availability of Nest Egg – Inventory 4.1.22, an important update to their easy-to-use, yet comprehensive inventory... Read more
Factor4, LLC Launches Apple iOS and Android G...
Factor4, LLC, which offers gift and loyalty services to the SMB marketplace, has released free mobile applications that enable merchants to process via all Apple and Android devices. The Apple and... Read more
15-inch Retina MacBook Pros on sale for $200...
B&H Photo has 15″ Retina Apple MacBook Pros on sale for $200 off MSRP. Shipping is free, and B&H charges NY tax only: - 15″ 2.2GHz Retina MacBook Pro: $1799 $200 off MSRP - 15″ 2.5GHz Retina... Read more
Apple refurbished iMacs available for up to $...
Apple has Certified Refurbished 2015 21″ & 27″ iMacs available for up to $350 off MSRP. Apple’s one-year warranty is standard, and shipping is free. The following models are available: - 21″ 3.... Read more
Check Apple prices on any device with the iTr...
MacPrices is proud to offer readers a free iOS app (iPhones, iPads, & iPod touch) and Android app (Google Play and Amazon App Store) called iTracx, which allows you to glance at today’s lowest... Read more
Apple price trackers, updated continuously
Scan our Apple Price Trackers for the latest information on sales, bundles, and availability on systems from Apple’s authorized internet/catalog resellers. We update the trackers continuously: - 15″... Read more
Apple refurbished 2016 13-inch MacBook Airs a...
Apple has Certified Refurbished 2016 13″ MacBook Airs available starting at $849. An Apple one-year warranty is included with each MacBook, and shipping is free: - 2016 13″ 1.6GHz/8GB/128GB MacBook... Read more
1.4GHz Mac mini on sale for $449, save $50
Adorama has the 1.4GHz Mac mini on sale for $50 off MSRP including free shipping plus NY & NJ sales tax only: - 1.4GHz Mac mini (Apple sku# MGEM2LL/A): $449 $50 off MSRP To purchase a mini at... Read more
Apple refurbished 2015 13-inch MacBook Airs a...
Apple has Certified Refurbished 2015 13″ MacBook Airs available starting at $759. An Apple one-year warranty is included with each MacBook, and shipping is free: - 2015 13″ 1.6GHz/4GB/128GB MacBook... Read more

Jobs Board

Systems Architecture Prototyping - *Apple*...
Changing the world is all in a day's work at Apple . If you love innovation, here's your chance to make a career of it. You'll work hard. But the job comes with more Read more
*Apple* Retail - Multiple Positions- Akron,...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Hardware Design Validation Engineer - *Apple...
Changing the world is all in a day's work at Apple . If you love innovation, here's your chance to make a career of it. You'll work hard. But the job comes with more Read more
Systems Architecture Prototyping - *Apple*...
Changing the world is all in a day's work at Apple . If you love innovation, here's your chance to make a career of it. You'll work hard. But the job comes with more Read more
*Apple* Retail - Multiple Positions- South B...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.