Archive for the 'Development' Category

Another creator pattern for clusters

Thursday, September 15th, 2011

This is about Cocoa, and in particular about class clusters. The problem I wanted to solve was having a class cluster with easily extendable hierarchy without too much interdependency. In my case, I want to create a number of different UITableViewCell descendants, depending on the particular data element the cell should handle. If the data […]

Don’t do parts.parts

Wednesday, November 17th, 2010

I just found another weirdness in Apple’s Objective C. If you have the same name for several components of an object path, the runtime starts stuttering and behaving very badly. Intermittently, you can’t scroll, or only extremely slowly, everything turns into molasses. No errors, mind, just mindbogglingly slow. This stuttering and slowness seems to affect […]

Is it nil or isn’t it?

Monday, October 4th, 2010

A bit of Objective-C weirdness I don’t quite get. The weirdness occurs if “view” in the code below is nil, that is if [idr getAsView:newFrame] returns nil. You’d expect the verticalOffset not to be incremented, but it is. Even though view is nil, view.frame.size.height still evaluates to “21” (in this case) and verticalOffset gets incremented. […]

Method forwarding in Objective-C

Friday, August 13th, 2010

I scraped together the following from a number of sources and got it to work fine and without compiler warnings. Interesting links are, among others: http://cocoawithlove.com/2008/03/construct-nsinvocation-for-any-message.html http://macdevelopertips.com/objective-c/objective-c-categories.html But, I get ahead of myself. The idea here is to have one object forward method invocations to another. Typically, you have a class responding to method A, […]

Solution: open the market

Monday, June 14th, 2010

Now we’ve arrived at the last of the solutions in my list, namely “Opening the market for smaller entrepreneurs”. There are a number of reasons we have to do this, and I’ve touched on most of them before in other contexts. The advantages of having a large all-in-one vendor to deliver a single system doing […]

Solution: less need for standards

Friday, June 11th, 2010

Around 1996 I was part of the CEN TC251 crowd for a while, not as a member but as an observer. CEN is the European standards organization, and TC251 is “Technical Committee 251″, which is the committee that does all the medical IT standardization. The reason I was involved is that I was then working […]

Solution: improved specifications

Wednesday, June 9th, 2010

The quality of our IT systems for health-care is pretty darn poor, and I think most people agree on that. There have been calls for oversight and certification of applications to lessen the risk of failures and errors. In Europe there is a drive to have health-care IT solutions go through a CE process, which […]

Solution: modular structure

Monday, June 7th, 2010

Forcing a large application into small independent parts that have to communicate with each other using minimal interfaces is always a good thing. Large monolithic applications go “fat and lazy” when there is no requirement to keep them split up. Also, the effort to expand and maintain the applications go through the roof. We know […]

Solution: Issues

Friday, June 4th, 2010

Ah, finally we arrive at solutions. The first in the series is the elephant in the room: issues. Why do I say “elephant in the room”? Because when a doctor examines and treats a patient, he thinks in “issues”, and the result of that thinking manifests itself in planning, tests, therapies, and follow-up. When he […]

Problem: no searcheability

Wednesday, May 19th, 2010

This post is part of a series detailing the problems of current electronic healthcare records. To orient yourself, you can start at the index page on “presentation” on the iota wiki. You will find this and other pages on that wiki as well. The wiki pages will be continuously updated. Since current electronic health care […]