[ 
https://issues.apache.org/jira/browse/JCR-5140?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Julian Reschke updated JCR-5140:
--------------------------------
    Description: 
There are a few use cases where a new namespace prefix needs to be computed for 
a given namespace name (this list may not be exhaustive):
 - when mapping expanded names to JCR names when the namespace name (URI) is 
not known in the repository (yet)
 - when importing content where namespace names (URIs) are known, but no 
prefixes are known
 - when registering a new namespace, but the specified prefix is already in use

Automatically generating the prefixes has several commons problems:
 - consistency: generating prefixes in different places and/or based on 
previous state of the registry (incrementing counters until new prefix found) 
causes prefix inconsistency across systems for no good reason
 - conciseness and readability: for certain namespaces, there are commonly used 
prefixes (such as in DC, XMPP etc), and it would be good to just use those when 
possible

Proposal: have a single place that offers help for generating prefixes (this 
ticket is in JCR space as jackrabbit-commons already has NamespaceHelper, but 
of course the location can be discussed).

Blue print:
{code:java}
// Suggests a prefix for the given namespace, based on
// well-known XML namespaces, or alternatively derived 
// from the namespace name.
public static String suggestPrefix(String namespace);

// as above, but will take exisiting prefixes into account
// this would be for the case where the prefix already exists
// but is mapped to a different namespace name.
// Lookup for existing prefix so that we can abstract out the 
// actual JCR interface (to be discussed)
public static String suggestPrefix(String namespace, Function<String, String> 
getNamespaceForPrefix);

// maybe more helpers:

public static boolean isValidNamespace(String namespace);
public static Map.Entry<String, String> extractPrefixAndNamespace(String 
jcrName, Function<String, String> getNamespaceForPrefix);{code}

We'd also need a hook to account for "internal", unless we want to hard-wire 
that into this.

  was:
There are a few use cases where a new namespace prefix needs to be computed for 
a given namespace name (this list may not be exhaustive):
 - when mapping expanded names to JCR names when the namespace name (URI) is 
not known in the repository (yet)
 - when importing content where namespace names (URIs) are known, but no 
prefixes are known
 - when registering a new namespace, but the specified prefix is already in use

Automatically generating the prefixes has several commons problems:
 - consistency: generating prefixes in different places and/or based on 
previous state of the registry (incrementing counters until new prefix found) 
causes prefix inconsistency across systems for no good reason
 - conciseness and readability: for certain namespaces, there are commonly used 
prefixes (such as in DC, XMPP etc), and it would be good to just use those when 
possible

Proposal: have a single place that offers help for generating prefixes (this 
ticket is in JCR space as jackrabbit-commons already has NamespaceHelper, but 
of course the location can be discussed).

Blue print:
{code:java}
// Suggests a prefix for the given namespace, based on
// well-known XML namespaces, or alternatively derived 
// from the namespace name.
public static String suggestPrefix(String namespace);

// as above, but will take exisiting prefixes into account
// this would be for the case where the prefix already exists
// but is mapped to a different namespace name.
// Lookup for existing prefix so that we can abstract out the 
// actual JCR interface (to be discussed)
public static String suggestPrefix(String namespace, Function<String, String> 
getNamespaceForPrefix);

// maybe more helpers:

public static boolean isValidNamespace(String namespace);
public static Map.Entry<String, String> extractPrefixAndNamespace(String 
jcrName, Function<String, String> getNamespaceForPrefix);{code}


> Improve support for generating namespace prefixes
> -------------------------------------------------
>
>                 Key: JCR-5140
>                 URL: https://issues.apache.org/jira/browse/JCR-5140
>             Project: Jackrabbit Content Repository
>          Issue Type: Task
>          Components: jackrabbit-jcr-commons
>            Reporter: Julian Reschke
>            Priority: Major
>
> There are a few use cases where a new namespace prefix needs to be computed 
> for a given namespace name (this list may not be exhaustive):
>  - when mapping expanded names to JCR names when the namespace name (URI) is 
> not known in the repository (yet)
>  - when importing content where namespace names (URIs) are known, but no 
> prefixes are known
>  - when registering a new namespace, but the specified prefix is already in 
> use
> Automatically generating the prefixes has several commons problems:
>  - consistency: generating prefixes in different places and/or based on 
> previous state of the registry (incrementing counters until new prefix found) 
> causes prefix inconsistency across systems for no good reason
>  - conciseness and readability: for certain namespaces, there are commonly 
> used prefixes (such as in DC, XMPP etc), and it would be good to just use 
> those when possible
> Proposal: have a single place that offers help for generating prefixes (this 
> ticket is in JCR space as jackrabbit-commons already has NamespaceHelper, but 
> of course the location can be discussed).
> Blue print:
> {code:java}
> // Suggests a prefix for the given namespace, based on
> // well-known XML namespaces, or alternatively derived 
> // from the namespace name.
> public static String suggestPrefix(String namespace);
> // as above, but will take exisiting prefixes into account
> // this would be for the case where the prefix already exists
> // but is mapped to a different namespace name.
> // Lookup for existing prefix so that we can abstract out the 
> // actual JCR interface (to be discussed)
> public static String suggestPrefix(String namespace, Function<String, String> 
> getNamespaceForPrefix);
> // maybe more helpers:
> public static boolean isValidNamespace(String namespace);
> public static Map.Entry<String, String> extractPrefixAndNamespace(String 
> jcrName, Function<String, String> getNamespaceForPrefix);{code}
> We'd also need a hook to account for "internal", unless we want to hard-wire 
> that into this.



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

Reply via email to