A Sensor is invoked once during the analysis of a project. The sensor can invoke a maven plugin, parse a flat file, connect to a web server... For example the Cobertura Sensor invokes the Codehaus Cobertura MOJO. Then the generated XML file is parsed is able to parse the cobertura XML report file generated during execution of your tests and used to save the first-level of measures on resources (project, package or class).
A sensor can access and save measures on the whole tree of resources. Sensor are generally used to add measure at the lowest level of the resource tree.
Decorators are triggered once all sensors have completed. Their decorate method is called on every resource of a certain level bottom up. Decorators can load (SELECT) read and save (INSERT) measures. The call is contextual, i.e it is only possible to access the resource and its children.
Decorators are generally used to consolidate / aggregate at higher levels, measures that have been added saved by Sensors at the lowest level.
Persistent properties are also accessible from the Web Service named 'properties'. To exclude some properties from anonymous requests, add the suffix ".secured" to the key (
my.property.secured). It can be useful for license keys for example.
Steps to cover a new language
- Write the grammar. This is the hardest part.
- Write a parser (a parser simply takes a grammar, an input, and will parse it, yielding a parse tree).
- Test your grammar, to ensure it is able to parse your real-life language files.
- Write a few parse tree visitors. Some visitors will compute metrics, while others will enforce coding rules. A dozen or so visitors is sufficient for an initial release.
- Write a SonarQube sensor to launch the visitors. It should query the API to get the list of source files, the list of active coding rules in the quality profile, and the API to save metrics and issues.
Tips and Tricks
- For generating charts use d3.js, which is packaged with SonarQube since version 4.1.
- To create "template" rules (rules that can be duplicated by the user) set the rule's
- To access a constant from a Java class in a .erb file, use J