NavuLeaf (NCS Java API Version 5.6)

Object
- com.tailf.navu.NavuNode
- - com.tailf.navu.NavuLeaf

Direct Known Subclasses:

NavuLeafList
```
public class NavuLeaf
extends NavuNode
```
The NavuLeaf class corresponds to the YANG leaf and leaf-list node types. A NavuLeaf is a node in the NAVU-Tree that that does not have any children and holds a value.
To retrieve a value the method NavuLeaf.value() should be called which on first invocation retrieves the value through the current context. Subsequent calls to the value method will return the "cached" value. It is important to understand that the first call to value method will cache the value in the instance which means that subsequent calls to the value will return the cached value. To clear the cache held by an instance of NavuLeaf, the method NavuLeaf.reset() should be called.

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`create()` Create an empty leaf node.
`NavuLeaf`	`delete()` Deletes a leaf.
`List<NavuNode>`	`deref()` Derefs a leafref and returns the referenced objects
`List<ConfXMLParam>`	`encodeValues()` Encodes the sub-tree including the current `NavuNode` as the topmost `NavuNode` as a `ConfXMLParam` array.
`List<ConfXMLParam>`	`encodeXML()` Encodes the sub-tree including the current `NavuNode` as the topmost `NavuNode` as a `ConfXMLParam` array.
`boolean`	`equals(Object o)` Compares the specified object with this `NavuLeaf` for equality.
`boolean`	`exists()` Tests for the existence of the leaf node.
`CdbSession`	`getCdbSession(CdbDBType dbType)` Deprecated.
`DiffIterateOperFlag`	`getChangeFlag()` Returns the latest change that this `NavuNode` has been a subject to by a transaction.
`ConfValue`	`getOldValue()`
`NavuNode`	`getParent()` Returns the parent of the node.
`ConfNamespace`	`getRootNS()` Returns the root namespace of the topmost ancestor.
`ConfXMLParam[]`	`getValues(String xml)` Read an arbitrary set of sub-elements of a container or list entry.
`boolean`	`idrefDerivedOrSelf(ConfIdentityRef base)`
`boolean`	`isKey()` Returns true if this `NavuLeaf` is a key node.
`void`	`reset()` When navigating through NAVU to a certain leaf and retrieving its value, this value will be cached.
`void`	`safeCreate()` Create an empty leaf node, silently succeeding if the leaf already exists
`Collection<NavuNode>`	`select(ConfObject[] query)`
`Collection<NavuNode>`	`select(List<String> path)`
`Collection<NavuNode>`	`select(String path)`
`void`	`set(ConfValue val)` Sets the value of the leaf node.
`void`	`set(String val)` Sets the value and tries to perform an update.
`NavuNode`	`setChange(List<ConfObject> kp, DiffIterateOperFlag op, ConfValue oldValue, NavuContext delContext)`
`void`	`setValues(String xml)` This method is almost identical to `NavuLeaf.set(String)` with the exception that the value should be wrapped inside XML tag.
`void`	`sharedCreate()` Create an empty leaf node, silently succeeding if the leaf already exists and also maintain the FASTMAP reference counter on the leaf.
`void`	`sharedSet(ConfValue val)` Sets the value of a leaf node with FastMap support, creating backpointers and reference counter similar to sharedCreate() All FastMap code shall (in principle) allways use this method instead of set()
`void`	`sharedSet(String val)` SharedSet using string representation of value.
`ConfKey`	`toKey()` Convert the leaf value to a ConfKey.
`String`	`toString()`
`ConfValue`	`value()` Returns the effective value on the first call, or cached value in the subsequent calls of this leaf.
`String`	`valueAsString()` Returns the Schema aware string representation of a leaf.
`void`	`valueUpdateInd(NavuNode child)`

Methods inherited from class com.tailf.navu.NavuNode
children, container, container, container, container, context, getChange, getChanges, getChanges, getChanges, getChanges, getChanges, getChanges, getConfPath, getInfo, getKeyPath, getName, getNavuNode, getValues, getXml, hashCode, leaf, leaf, leaf, leaf, leafList, leafList, leafList, leafList, list, list, list, list, namespace, prepareXMLCall, setValues, sharedSetValues, sharedSetValues, startCdbSession, stopCdbSession, xPathSelect, xPathSelectIterate

Methods inherited from class Object
getClass, notify, notifyAll, wait, wait, wait

- Method Detail
  - isKey
```
public boolean isKey()
```
    Returns true if this NavuLeaf is a key node.
    
    Returns:
    
    true whether this NavuLeaf is a key node false otherwise
  - delete
```
public NavuLeaf delete()
                throws NavuException
```
    Deletes a leaf.
    
    Returns:
    
    a pointer to self.
    
    Throws:
    
    NavuException
  - encodeXML
```
public List<ConfXMLParam> encodeXML()
                             throws NavuException
```
    Description copied from class: NavuNode
    Encodes the sub-tree including the current NavuNode as the topmost NavuNode as a ConfXMLParam array.
    The returned ConfXMLParam array contains no values except for list keys. The leaf elements are encoded as ConfXMLParamLeaf. Therefore, the returning array can be used as a the input parameter to NavuNode.getValues(ConfXMLParam[]) on the current node's parent.
    NavuNode node = ...; ConfXMLParam[] cxa = node.encodeXML().toArray(new ConfXMLParam[0]); // cxa contains a structure that does not contain values except for // keys in list elements NavuNode parent = node.getParent(); ConfXMLParam[] cxb = parent.getValues(cxa); // cxb contains the same sub-tree with all the values
    Specified by:
    
    encodeXML in class NavuNode
    
    Returns:
    
    A list of ConfXMLParam objects corresponding to the sub-tree of this node, with no values except list keys.
    
    Throws:
    
    NavuException
    
    See Also:
    
    ConfXMLParam, ConfXMLParamValue
  - encodeValues
```
public List<ConfXMLParam> encodeValues()
                                throws NavuException
```
    Description copied from class: NavuNode
    
    Encodes the sub-tree including the current NavuNode as the topmost NavuNode as a ConfXMLParam array.
    As opposed to NavuNode.encodeXML(), the returned ConfXMLParam array does contain values in the form of ConfXMLParamValue
    
    Specified by:
    
    encodeValues in class NavuNode
    
    Returns:
    
    A list of ConfXMLParam objects corresponding to the sub-tree of this node, including all values.
    
    Throws:
    
    NavuException
    
    See Also:
    
    ConfXMLParam, ConfXMLParamValue
  - reset
```
public void reset()
```
    When navigating through NAVU to a certain leaf and retrieving its value, this value will be cached. This method will reset the cache and indicate that the value should be re-read next time the value is retrieved.
    
    Specified by:
    
    reset in class NavuNode
  - select
```
public Collection<NavuNode> select(List<String> path)
                            throws NavuException
```
    Specified by:
    
    select in class NavuNode
    
    Parameters:
    
    path - a list of regular expression.
    
    Returns:
    
    a collection a nodes marching the query
    
    Throws:
    
    NavuException
  - select
```
public Collection<NavuNode> select(String path)
                            throws NavuException
```
    Specified by:
    
    select in class NavuNode
    
    Parameters:
    
    path - a "/" separated regular expression.
    
    Returns:
    
    a collection a nodes marching the query
    
    Throws:
    
    NavuException
  - getValues
```
public ConfXMLParam[] getValues(String xml)
                         throws NavuException
```
    Description copied from class: NavuNode
    Read an arbitrary set of sub-elements of a container or list entry.
    The xml string must be pre-populated with tags and parameterized values ("?") which indicate that the operation should read the values of the corresponding tags.
    
    NOTE: The specified xml string should not contain the version tag (<?xml version="1.0" encoding="UTF-8"?>) and do not wrap xml string with current node tag.
    Example - Get tree in a service model:
    list buzz-service { key name; leaf name { type string; } uses ncs:service-data; ncs:servicepoint buzz-service-servicepoint; container buzz { container servers { list server { key "srv-name"; max-elements "64"; leaf srv-name { type string; } leaf ip { type inet:host; mandatory true; } leaf port { type inet:port-number; default "80"; } container foo { leaf bar { type int64; default "42"; } leaf baz { type int64; default "7"; } } list interface { key "if-name"; max-elements "8"; leaf if-name { type string; } leaf mtu { type int64; default "1500"; } } } } } } NavuContainer buzz = ncsRoot.container(buzzService.hash) .list(buzzService._buzz_service) .elem("service1") .container(buzzService._buzz); ConfXMLParam[] param = buzz.getValues("<buzz xmlns=\"http://com/example/buzzservice\">" + "<servers><server><srv-name>www1</srv-name>" + "<ip>?</ip></server><server>" + "<srv-name>www2</srv-name><ip>?</ip>" + "</server></servers></buzz>");
    Overrides:
    
    getValues in class NavuNode
    
    Parameters:
    
    xml - XML structure corresponding to the part of the configuration tree that is to be fetched.
    
    Throws:
    
    NavuException
  - sharedSet
```
public void sharedSet(ConfValue val)
               throws NavuException
```
    Sets the value of a leaf node with FastMap support, creating backpointers and reference counter similar to sharedCreate() All FastMap code shall (in principle) allways use this method instead of set()
    
    Throws:
    
    NavuException
  - sharedSet
```
public void sharedSet(String val)
               throws NavuException
```
    SharedSet using string representation of value. Sets the value of a leaf node with FastMap support, creating backpointers and reference counter similar to sharedCreate() All FastMap code shall (in principle) always use this method instead of set()
    
    Throws:
    
    NavuException
  - set
```
public void set(ConfValue val)
         throws NavuException
```
    Sets the value of the leaf node.
    When setting a leaf node the cached value inside the instance is reflected. Subsequent calls to value retrieves the cached value.
    Setting a leaf value is only valid when writing to a transaction or when writing to operational data store.
    When writing to the operational data store the write is done with the CdbLockType.LOCK_REQUEST lock type set.
    
    Parameters:
    
    val - - the value to set
    
    Throws:
    
    NavuException - If an error occurred when setting the leaf value the underlying/caused exception is wrapped inside the NavuException and should be retrieved through getCause method of Throwable.
    An IllegalArgumentException is wrapped inside a NavuException if writes is done to running with NavuContext created with CdbSession or Cdb.
  - setValues
```
public void setValues(String xml)
               throws NavuException
```
    This method is almost identical to NavuLeaf.set(String) with the exception that the value should be wrapped inside XML tag.
    For example to set the value "123" it needs to be wrapped with "<leaf-name>123 </leaf-name>.
    
    Overrides:
    
    setValues in class NavuNode
    
    Parameters:
    
    xml - A string value wrapped inside XML tag.
    
    Throws:
    
    NavuException
    
    See Also:
    
    NavuNode.setValues(ConfXMLParam[]), ConfXMLParam
  - set
```
public void set(String val)
         throws NavuException
```
    Sets the value and tries to perform an update. For this to succeed, it must be possible to convert this string value into a value consistent with the type of the NavuLeaf. For example "123" if the YANG model has a leaf of, for example "int32".
    
    Parameters:
    
    val - The string representation of a new value. For this to succeed, it must be possible to convert this string value into a value consistent with the type of the NavuLeaf. For example "123" if the YANG model has a leaf of, for example "int32".
    
    Throws:
    
    NavuException
  - exists
```
public boolean exists()
               throws NavuException
```
    Tests for the existence of the leaf node.
    
    Specified by:
    
    exists in class NavuNode
    
    Returns:
    
    boolean
    
    Throws:
    
    NavuException - on failure
  - create
```
public void create()
            throws NavuException
```
    Create an empty leaf node.
    
    Throws:
    
    NavuException - on failure to create
  - safeCreate
```
public void safeCreate()
                throws NavuException
```
    Create an empty leaf node, silently succeeding if the leaf already exists
    
    Throws:
    
    NavuException - on failure to create
  - sharedCreate
```
public void sharedCreate()
                  throws NavuException
```
    Create an empty leaf node, silently succeeding if the leaf already exists and also maintain the FASTMAP reference counter on the leaf.
    
    Throws:
    
    NavuException - on failure to create
  - toKey
```
public ConfKey toKey()
              throws NavuException
```
    Convert the leaf value to a ConfKey. This is convenient, but only works for lists that have singleton keys.
    
    Returns:
    
    the leaf value represented as a key.
    
    Throws:
    
    NavuException
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - value
```
public ConfValue value()
                throws NavuException
```
    Returns the effective value on the first call, or cached value in the subsequent calls of this leaf.
    After this method has been called the first time it stores the value in this object which means that subsequent calls to this method will return the cached value.
    
    Returns:
    
    the effective value (first call) or cached value in subsequent calls of this leaf.
    
    Throws:
    
    NavuException
  - valueAsString
```
public String valueAsString()
                     throws NavuException
```
    Returns the Schema aware string representation of a leaf.
    An example of the difference between this method and toString() is for ConfEnumerations where the schema aware representation is the label while toString() returns a representation of the ordinal value.
    
    Returns:
    
    String representation of the leaf
    
    Throws:
    
    NavuException
  - valueUpdateInd
```
public void valueUpdateInd(NavuNode child)
```
    Specified by:
    
    valueUpdateInd in class NavuNode
  - getChangeFlag
```
public DiffIterateOperFlag getChangeFlag()
```
    Description copied from class: NavuNode
    
    Returns the latest change that this NavuNode has been a subject to by a transaction.
    
    Overrides:
    
    getChangeFlag in class NavuNode
    
    Returns:
    
    Flag for the latest change
    
    See Also:
    
    DiffIterateOperFlag
  - getOldValue
```
public ConfValue getOldValue()
```
    Returns:
    
    the old value. null if no old value exists.
  - setChange
```
public NavuNode setChange(List<ConfObject> kp,
                          DiffIterateOperFlag op,
                          ConfValue oldValue,
                          NavuContext delContext)
                   throws NavuException
```
    Specified by:
    
    setChange in class NavuNode
    
    Throws:
    
    NavuException
  - getParent
```
public NavuNode getParent()
```
    Description copied from class: NavuNode
    
    Returns the parent of the node.
    
    Overrides:
    
    getParent in class NavuNode
    
    Returns:
    
    - this node parent or null if this NavuNode represents the root node.
  - select
```
public Collection<NavuNode> select(ConfObject[] query)
```
    Specified by:
    
    select in class NavuNode
    
    Returns:
    
    a collection a nodes matching a Regular Expression query
  - getCdbSession
```
@Deprecated
public CdbSession getCdbSession(CdbDBType dbType)
```
    Deprecated.
    
    This method is deprecated. Use one of NavuContextBase.getReadConfSession(), NavuContextBase.getReadConfSession() or NavuContextBase.getWriteOperSession() instead.
    
    Overrides:
    
    getCdbSession in class NavuNode
    
    Returns:
    
    The current CdbSession or null if this node is attached to a Maapi context
  - getRootNS
```
public ConfNamespace getRootNS()
```
    Description copied from class: NavuNode
    
    Returns the root namespace of the topmost ancestor.
    
    Overrides:
    
    getRootNS in class NavuNode
    
    Returns:
    
    topmost namespace.
  - deref
```
public List<NavuNode> deref()
                     throws NavuException
```
    Derefs a leafref and returns the referenced objects
    
    Returns:
    
    array of keypaths where each keypath is an array of ConfObject
    
    Throws:
    
    NavuException
  - idrefDerivedOrSelf
```
public boolean idrefDerivedOrSelf(ConfIdentityRef base)
                           throws NavuException
```
    Throws:
    
    NavuException
  - equals
```
public boolean equals(Object o)
```
    Compares the specified object with this NavuLeaf for equality. Returns true if the given object is also a NavuLeaf and it has the same ConfPath as this NavuLeaf. Note that the actual values held by the leaves (if any) are ignored as they are not relevant to this comparison.
    
    Specified by:
    
    equals in class NavuNode
    
    Parameters:
    
    o - the object to be compared for equality with this NavuLeaf
    
    Returns:
    
    true if the specified object is equal to this NavuLeaf

Class NavuLeaf

Method Summary

Methods inherited from class com.tailf.navu.NavuNode

Methods inherited from class Object

Method Detail

isKey

delete

encodeXML

encodeValues

reset

select

select

getValues

sharedSet

sharedSet

set

setValues

set

exists

create

safeCreate

sharedCreate

toKey

toString

value

valueAsString

valueUpdateInd

getChangeFlag

getOldValue

setChange

getParent

select

getCdbSession

getRootNS

deref

idrefDerivedOrSelf

equals