Internal metadata structure and basic usage (v 3.3)

The Metadata add-on has two basic structure elements: Metadata sets and Metadata fields. A set contains one ore more fields. The basic set and field handling is available via the "com.communardo.confluence.metadata.service.MetadataManager". 

Just inject it into your classes with constructor injection or setter injection. The injection itself only works, if you have defined a correct component-import in your atlassian-plugin.xml (please see Quick Setup of Metadata API (v 3.3)). 

Loading all available metadata sets 
 

List<MetadataSet> sets = metadataManager.loadMetadataSets();

This should give you the space metadata sets as well as the global metadata sets.

Or just load the metadata sets of a specific space:

//load the metadata sets of a space with the spacekey "demo"
List<MetadataSet> sets = metadataManager.loadMetadataSets("demo");

Iterate through metadata fields of a set
 

for (MetadataField metadataField : metadataset.getMetadataFields()) {
    
}

Read a metadata field value on a page or blog post

Each metadata field stores data objects, but only the metadata field type knows how to handle them. Field types are Checkbox; Textfield; Userfield and so on. So, first we need to load the data object. We use the "loadContentMetadataValue" method for that purpose.

DataObject dataObject = metadataManager.loadContentMetadataValue(ceo, metadataField);

Now that we have the data object, we can ask the field type of the metadata field to render it for us.

metadataField.renderData(dataObject, ceo);

Because the field type knows all the things internally, we can also ask it directly for the view representation. 

metadatafield.getType().renderView(ceo);