CmSubscriptionService service layer methods

References

CPS-2023: CmSubscription service layer methodsClosed

Issues & Decisions

#	Issue	Notes	Decisions

#	Issue	Notes	Decisions
1

Overview

This page is for the list of service layer methods needed to interact with other cps service methods and the repository layer in order to fetch/persist/delete the CmSubscriptions.

#	Use Case	Method Details

#

Use Case

Method Details

1

Fetch collection of datanodes based on given datastore and list of cmhandle-ids for a given xpath

2

Persist the newly created subscription / append the subscription-id if it is an overlapping one

3

Check if there is an ongoing subscription for the given datastore , cmHandleId , xpath

@Daniel Hanrahan

// Check if a subscription does NOT exist in the DB
boolean isNewSubscription(final String datastore, final String cmHandleId, final String xpath) {
    final String cpsPathQuery = 
        "/datastores/datastore[@name='" + escapeQuotesByDoublingThem(datastore) + "']" + 
        "/cm-handles/cm-handle[@id='" + escapeQuotesByDoublingThem(cmHandleId) + "']" + 
        "/filters/filter[@xpath='" + escapeQuotesByDoublingThem(xpath) + "']";

    final Collection<DataNode> existingNodes = queryDataNodes("NCMP-Admin", "cm-data-subscriptions", cpsPathQuery, OMIT_DESCENDANTS);

    return existingNodes.isEmpty() || existingNodes.iterator().next().getLeaves().get("subscribers").isEmpty();
}

// This is needed in case subscribed xpath has single-quotes ' in it - that would break path query
private static String escapeQuotesByDoublingThem(final String value) {
    return value.replace("'", "''");
}


Can be called like below : 
final String datastoreName = cmSubscriptionPredicate.getScopeFilter().getDatastoreType().getDatastoreName():
for (final String cmHandleId : cmSubscriptionPredicate.getTargetFilter()) {
for (final String xpath : cmSubscriptionPredicate.getScopeFilter().getXpathFilters()) {
if (isNewSubscription(datastoreName, cmHandleId, xpath)) {
// will need to send this to dmi
}
}
}