That uses the Helper Libraries.
To access metadata without the Helper Libraries see openhab-helper-libraries/Core/automation/lib/python/core/metadata.py at ivans-updates · CrazyIvan359/openhab-helper-libraries · GitHub
In JavaScript without the Helper Libraries I’ve this library:
(function(context) {
'use strict';
// Use the logger from the caller if available, otherwise create a Metadata logger
var log = (context.logger === undefined) ? Java.type("org.slf4j.LoggerFactory").getLogger("org.openhab.model.script.Rules.Metadata") : context.logger;
// Get the metadata registry and relevant classes
var FrameworkUtil = Java.type("org.osgi.framework.FrameworkUtil");
var _bundle = FrameworkUtil.getBundle(scriptExtension.class);
var bundle_context = _bundle.getBundleContext()
var MetadataRegistry_Ref = bundle_context.getServiceReference("org.openhab.core.items.MetadataRegistry");
var MetadataRegistry = bundle_context.getService(MetadataRegistry_Ref);
var Metadata = Java.type("org.openhab.core.items.Metadata");
var MetadataKey = Java.type("org.openhab.core.items.MetadataKey");
/**
* Merges two configruation maps.
* param{object} origConf original configuration
* param{object} newConf new configuration
*/
context._mergeConf = function(origConf, newConf) {
var merged = {};
for (var property in origConf) {
merged[property] = origConf[property];
}
for (var property in newConf) {
merged[property] = newConf[property];
}
return merged;
}
/**
* Deletes the specified metadata on the Item.
* @param {string} itemName name of the item to delete the metadata from
* @param {string} namespace namespace to delete, if not specificed delete all metadata
*/
context.deleteMetadata = function(itemName, namespace){
namespace = namespace || null;
if(!namespace){
log.warn("Deleting ALL metadata on Item " + itemName);
MetadataRegistry.removeItemMetadata(itemName);
}
else {
MetadataRegistry.remove(new MetadataKey(namespace, itemName));
}
};
/**
* Sets the full metadata on the passed in Item.
* @param {string} itemName the name of the Item to set the metadata on
* @param {string} namespace metadata namespace
* @param {string} value metadata value for the namespace
* @param {object} configuration metadata configuration
* @param {bool} overwrite, when true the namespace will be deleted before updated
*/
context.setMetadata = function(itemName, namespace, value, configuration, overwrite) {
overwrite = overwrite || false;
value = value || null;
if(overwrite){
deleteMetadata(itemName, namespace);
}
var curr = getMetadata(itemName, namespace);
var key = new MetadataKey(namespace, itemName);
// If overwriting or there is no metadata, just add it
if(overwrite || curr === null){
var metadata = new Metadata(key, value, configuration);
MetadataRegistry.add(metadata);
}
// Merge the changes with what already there
else {
if(!value){
value = curr.value
}
var mergedConf = _mergeConf(curr.configuration, configuration);
MetadataRegistry.update(new Metadata(key, value, mergedConf));
}
};
/**
* Sets or updates the Item metadata's value.
* @param {string} itemName the name of the item
* @param {string} namespace
* @param {string} value
*/
context.setMetadataValue = function(itemName, namespace, value) {
var curr = getMetadata(itemName, namespace);
if (curr) {
setMetadata(itemName, namespace, value, curr.configuration, true);
} else {
setMetadata(itemName, namespace, value, {}, false);
}
};
/**
* Returns the metadata on the passed in item name with the given namespace.
* @param {string} itemName name of the item to search the metadata on
* @param {string} namespace namespace of the metadata to return
* @return {Metadata} the value and configuration or null if the metadata doesn't exist
*/
context.getMetadata = function(itemName, namespace) {
return MetadataRegistry.get(new MetadataKey(namespace, itemName));
};
/**
* Returns the value of the indicated namespace
* @param {string} itemName name of the item to search the etadata on
* @param {string} namespace namespace to get the value from
* @return {string} The value of the given namespace on the given Item, or null if it doesn't exist
*/
context.getMetadataValue = function(itemName, namespace) {
var md = getMetadata(itemName, namespace);
return (md === null) ? null : md.value;
};
/**
* Returns the configuration of the given key in the given namespace
* @param {string} itemName name of the item to search for metadata on
* @param {string} namespace namespace of the metadata
* @param {string} key name of the value from config to return
* @return {string} the value assocaited with the key, null otherwise
*/
context.getMetadataKeyValue = function(itemName, namespace, key){
var md = getMetadata(itemName, namespace);
if(md === null){
return null;
}
return (md.configuration[key] === undefined) ? null : md.configuration[key];
};
/**
* Returns the value of the name metadata, or itemName if name metadata doesn't exist on the item
* @param {string} itemName name of the Item to pull the human friendly name metdata from
*/
context.getName = function(itemName) {
var name = getMetadataValue(itemName, "name");
return (name === null) ? itemName : name;
};
/**
* Filters the members of the passed in group and generates a comma separated list of
* the item names (based on metadata if available).
* @param {string} groupName name of the group to generate the list of names from
* @param {function} filterFunc filtering function that takes one Item as an argument
*/
context.getNames = function(groupName, filterFunc) {
var Collectors = Java.type("java.util.stream.Collectors");
return context.ir.getItem(groupName)
.members
.stream()
.filter(filterFunc)
.map(function(i) {
return context.getName(i.name);
})
.collect(Collectors.joining(", "));
};
})(this)
Or in a more concise “just the parts I need” example:
// Accessing Item Metadata
var logger = Java.type("org.slf4j.LoggerFactory").getLogger("org.openhab.model.script.Rules.Examples");
logger.info("Trying to extract a metadata value")
var FrameworkUtil = Java.type("org.osgi.framework.FrameworkUtil");
var _bundle = FrameworkUtil.getBundle(scriptExtension.class);
var bundle_context = _bundle.getBundleContext()
var classname = "org.openhab.core.items.MetadataRegistry"
var MetadataRegistry_Ref = bundle_context.getServiceReference("org.openhab.core.items.MetadataRegistry");
var MetadataRegistry = bundle_context.getService(MetadataRegistry_Ref);
var methods = MetadataRegistry.class.getDeclaredMethods();
logger.info("There are " + methods.length + " methods");
for each (var m in methods) {
logger.info(m.toString());
}
var Metadata = Java.type("org.openhab.core.items.Metadata");
var MetadataKey = Java.type("org.openhab.core.items.MetadataKey");
var metadata = MetadataRegistry.get(new MetadataKey("name", "vArgus_Status"));
logger.info("vArgus_Status's name is " + metadata.value);