Package-only dependencies in Maven

Sometimes you have a Maven project that needs dependencies for running tests that you do not want ending up in the final packaged WAR. We all know the test directive in the POM that accomplishes this. You might also have dependencies that are only required at runtime and need to be in the WAR but not on the compile classpath. Normally you would use the runtime directive in the POM.

Consider a situation where we have a dependency that we want to be available at runtime (in the WAR), but not on the classpath during the execution of our tests. A nice example of this is logging implementations: we want to use the slf4j-simple implementation for running unit tests, but we want logback-classic to be packaged in the WAR.

To accomplish this, you can use the maven-dependency-plugin as illustrated in the following POM snippet:

This way you have a single logging implementation on the classpath when running tests (slf4j-simple) and a single logging implementation for runtime in the final packaged WAR (logback).

Example source code

Javascript oneliners: functions are attributes too

Just a small reminder. Javascript allows you to call methods based on their name. So if a DOM element has a addClass and removeClass which both take the same argument we could write:

but we could also write

Sometimes this means you can use this technique to write powerful one liners.

Awesome Asciidoc: Change URI Scheme for Assets

When we define the document attribute icons with the value font the FontAwesome fonts are loaded in the generated HTML page. In the head section of the HTML document a link element to the FontAwesome CSS on https://cdnjs.cloudflare.com/ajax/libs is added. Also when we use the highlight.js or Prettify source highlighter a link to the Javascript files on the cdnjs.cloudflare.com server is generated. We can change the value of the scheme from https to http by setting the attribute asset-uri-scheme to http. Or we can leave out the scheme so a scheme-less URI is generated for the links. A scheme-less URI provides the benefit that the same protocol of the origin HTML page is used to get the CSS or Javascript files from the cdnjs.cloudflare.com server. Remember this might provide a problem if the HTML page is opened locally.

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Gradle Goodness: Suppress Progress Logging

Gradle has some sophisticated progress logging on the console. For example we can see how much percentage of the building process is done. The percentage value is updated on the same console line. The following snippet is a sample of such output > Building 0% > :dependencies > Resolving dependencies ':compile'. The information is updated on the same line, which is really nice. But sometimes we might need to run Gradle builds on a system that doesn’t support this mechanism on the console or terminal, possibly an continuous integration server. To disable the progress logging we can set the environment variable TERM to the value dumb.

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Awesome Asciidoc: Adding Line Numbers to Source Code Listings

When we write technical documentation with Asciidoctor we can easily include source code listings. When we use the coderay or pygments source code highlighter we can also include line numbers. We must add the attribute linenums to the listing block in our markup. This attribute is used by the source highlighters to create and format the line numbers. We can specify that the line numbers must be generated in table mode or inline mode. When the line numbers are in table mode we can select the source code without the line numbers and copy it to the clipboard. If we use inline mode the line numbers are selectable and are copied together with the selected source code to the clipboard. To specify which mode we want to use for the line numbers we use the document attribute coderay-linenums-mode or pygments-linenums-mode depending on the source highlighter we use. We can use the values table (default) or inline.

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Awesome Asciidoc: Changing Highlight.js Theme

Asciidoctor is a great tool for writing technical documentation. If we have source code in the Asciidoc markup we can set the document attribute source-highlighter to pigments, coderay, prettify and highlightjs. When we use highlight.js we can also add an extra document attribute highlightjs-theme with the value of a highlight.js theme. If we do not specify the highlightjs-theme the default theme github is used.

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