Programming

I’ve recently been involved in upgrading a AngularJS + UI-Bootstrap + UI Router project to Angular 7 + ngx-bootstrap + UI Router. The reason for the upgrade was that the support for a lot of the other components was fading, and the availability of new components was far better for Angular 7 than AngularJS. Having said that, AngularJS is still going strong for better or worse. The approach was to use the Angular Upgrade module which allowed a component-by-component upgrade, and basically seamless interop between the two versions. This was helped a lot by the use of UI Router which navigates to both AngularJS and Angular 7 container components. ...

Out of the box Jenkins can extract the metadata from Maven build for use as environment variables in the build steps, but it doesn’t have the same support for Gradle. This can be achieved using the EnvInject plugin, and a custom task in your build.gradle file. The first step is to setup a task in build.gradle that will print out the project name and version in a format that can be used directly in a properties file. ...

Update A good explaintation of what is happening is provided here. In this day and age dateutil.tz is the better solution to timezones, as it works as expected with datetime. TL;DR The crux of this post is, make sure to never use datetime.replace(tzinfo=...) when working with PyTZ, use tz.localize(...) instead, otherwise you’ll end up with some very strange times. The PyTZ docs do mention this helper method as a way to fix incorrect conversion across timezones, but out of the box PyTZ timezones seem odd. Consider this simple code that takes both the native datetime.replace approach, and the localize approach: ...

Python usually relies of duck typing for type safety, but from time to time it can be handy to enforce some type checking, particularly when new users are going to be using your objects. The following are three utility methods for applying type checking to class properties, using the new style object property() method. def deleter(attr): """Deleter closure, used to remove the inner variable""" def deleter_real(self): return delattr(self, attr) return deleter_real def getter(attr): """Getter closure, used to simply return the inner variable""" def getter_real(self): return getattr(self, attr) return getter_real def setter(attr, valid_types): """Setter closure, used to do type checking before storing var""" def setter_real(self, var): if not isinstance(var, valid_types): raise TypeError("Not of required type: "+str(valid_types)) setattr(self,attr,var) return setter_real def typed(attr, valid_types, docs=""): """Wrapper around property() so that we can easily apply type checking to properties""" return property(getter(attr), setter(attr, valid_types), deleter(attr), docs) # Example class class A(object): a = typed("_a", int) # Testing output a1 = A() a1.a = 1 print "Got stored value = " + str(a1.a) a1.a = "1" The results are: ...

It is often handy to be able to extract the Maven version of your project at run time, either for displaying in an about box, or in debugging information. One option is to read /META-INF/maven/${groupId}/${artifactId}/pom.properties. However, this file is only available in the packaged version of your project, so during development the method will fail. The approach I’ve taken to fulfil this requirement is to create a text (properties) file in the project resources, and have Maven process this. This allows Maven to inject the version number during compile. The following snippets need to be configured. ...

These are some project idea’s I’ve been sitting on all year and have not yet started, but hope to in the new year. 1. Python CMS framework in the vein of Drupal, based on Repoze BFG So Drupal is quite a popular community building framework, with good plugin system, and a data model which seems to work well. But I don’t think PHP is the way of the future, at least for me. I use Python for many other projects, I understand how to debug, unit test, etc. And BFG brings the really nice framework features from Zope and Plone, which makes it an ideal starting point. I’ve got a project plan for this which I’ll reveal when I get around to cutting some code. ...

After programming for Zope3/Plone for the past year I’ve come to really admire the flexibility and elegance that their implementation of the adapter pattern gives us. And, after Martin Aspeli put the call out almost a year ago, and it has not yet been answered, I thought it was time to give it a go. How hard could it be. So, what I’ve developed is a very simple, no dependency, maven available library which should greatly improve the flexibility of your code. ...

The situation is this. I had a working application which used Hibernate annotated classes, and JTA for data bindings, within a spring framework. Then I moved the annotated classes into a Jar file, and the application stopped working. Hibernate knew nothing about the classes because the PersistenceAnnotationBeanPostProcessor does not traverse into the JARS on the classpath. Further neither the entity manager or HibernateJpaVendorAdapter have options to specify the explicit paths to the classes. ...

Some brief background. Ant is the stock standard Java build system, much as Make is for C/C++. Maven is a newer Java build system which tried to, amongst other things, solver the Jar dependency hell problem, as well as make a standard project directory layout. From the Maven guide: <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.9</version> </dependency> Now when you go to compile with maven it goes and gets all the dependencies, puts them in your local repository (~/.m2/repository) and then into your project’s build class path. This is covered in more detail at the Maven website. ...

function spawn() { NODE=$1 COUNT=$2 echo Spawning $COUNT on $NODE rsh $NODE -n “~/mark.sh” & #rsh $NODE -n “cd $PWD ; ./run.sh –agent –threads $COUNT” & } LAST= COUNT=0 for N in $NODES ; do if [ “$N” = “$LAST” ] ; then COUNT=$[COUNT+1] else if [ 0 -ne $COUNT ] ; then spawn $LAST $COUNT fi COUNT=1 LAST=$N fi done if [ 0 -ne $COUNT ] ; then spawn $LAST $COUNT fi ...