Groovy is a superset of Java, i.e. any valid Java program is also a valid Groovy program. What it makes much easier than Java is the creation of data structures \u2013 no boilerplate constructors and initialisation and the like. Here are some key resources for learning Groovy:<\/p>\n
- \n
- Groovy Language Documentation<\/a><\/li>\n
- Groovy Playground<\/a><\/li>\n
- Groovy Scripting in hale studio<\/a><\/li>\n<\/ul>\n
The following posts should help you with some common challenges. Please note that this article assumes you have working knowledge of hale studio and know the terminology<\/a>.<\/p>\n
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<\/p>\nMonday's Script: Create a persistent ID for your target object (Johanna)<\/h2>\n
Sometimes, you can't just use a property of a source object to create a unique, persistent ID on the target side. The source object might not have an unique ID, or you might have to merge several source objects. If you just use Generate sequential ID<\/em> or Generate unique ID<\/em>, the ID will not be persistent across multiple transformation runs.<\/p>\n
If a combination of attributes of the source objects can be found that is unique and stable over time, the values of those attributes can be used to generate an unique ID on the target side that is persistent.<\/p>\n
To generate an ID from several source attributes, you can use the function
_.crypto.sha256<\/code> which is part of the standard Groovy helper functions. The function creates a hash for a string and, as long as the inputString<\/code> is stable, the generated hash value will also be stable.<\/p>\nWhen using the generated hash as an ID, you should always use a prefix (e.g. the feature type name followed by an underscore) as the hash value might start with a number which is not allowed in a
gml:id<\/code>.<\/p>\nHere is an example for mapping the
gml:id<\/code> attribute of aRoad<\/code> object of in the INSPIRE Transport Network Roads schema:<\/p>\n - Groovy Playground<\/a><\/li>\n