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OGR_SRSNode Class Reference

Objects of this class are used to represent value nodes in the parsed representation of the WKT SRS format. More...

#include <ogr_spatialref.h>

Public Member Functions

 OGR_SRSNode (const char *=NULL)
 Constructor. More...
 
int IsLeafNode () const
 Return whether this is a leaf node. More...
 
int GetChildCount () const
 Get number of children nodes. More...
 
OGR_SRSNodeGetChild (int)
 Fetch requested child. More...
 
const OGR_SRSNodeGetChild (int) const
 Fetch requested child. More...
 
OGR_SRSNodeGetNode (const char *)
 Find named node in tree. More...
 
const OGR_SRSNodeGetNode (const char *) const
 Find named node in tree. More...
 
void InsertChild (OGR_SRSNode *, int)
 Insert the passed node as a child of target node, at the indicated position. More...
 
void AddChild (OGR_SRSNode *)
 Add passed node as a child of target node. More...
 
int FindChild (const char *) const
 Find the index of the child matching the given string. More...
 
void DestroyChild (int)
 Remove a child node, and it's subtree. More...
 
void ClearChildren ()
 Clear children nodes.
 
void StripNodes (const char *)
 Strip child nodes matching name. More...
 
const char * GetValue () const
 Fetch value string for this node. More...
 
void SetValue (const char *)
 Set the node value. More...
 
void MakeValueSafe ()
 Massage value string, stripping special characters so it will be a database safe string. More...
 
OGRErr FixupOrdering ()
 Correct parameter ordering to match CT Specification. More...
 
OGR_SRSNodeClone () const
 Make a duplicate of this node, and it's children. More...
 
OGRErr importFromWkt (char **)
 Import from WKT string. More...
 
OGRErr exportToWkt (char **) const
 Convert this tree of nodes into WKT format. More...
 
OGRErr exportToPrettyWkt (char **, int=1) const
 Convert this tree of nodes into pretty WKT format. More...
 
OGRErr applyRemapper (const char *pszNode, char **papszSrcValues, char **papszDstValues, int nStepSize=1, int bChildOfHit=FALSE)
 Remap node values matching list. More...
 

Detailed Description

Objects of this class are used to represent value nodes in the parsed representation of the WKT SRS format.

For instance UNIT["METER",1] would be rendered into three OGR_SRSNodes. The root node would have a value of UNIT, and two children, the first with a value of METER, and the second with a value of 1.

Normally application code just interacts with the OGRSpatialReference object, which uses the OGR_SRSNode to implement it's data structure; however, this class is user accessible for detailed access to components of an SRS definition.

Constructor & Destructor Documentation

OGR_SRSNode::OGR_SRSNode ( const char *  pszValueIn = NULL)
explicit

Constructor.

Parameters
pszValueInthis optional parameter can be used to initialize the value of the node upon creation. If omitted the node will be created with a value of "". Newly created OGR_SRSNodes have no children.

Member Function Documentation

void OGR_SRSNode::AddChild ( OGR_SRSNode poNew)

Add passed node as a child of target node.

Note that ownership of the passed node is assumed by the node on which the method is invoked ... use the Clone() method if the original is to be preserved. New children are always added at the end of the list.

Parameters
poNewthe node to add as a child.
OGRErr OGR_SRSNode::applyRemapper ( const char *  pszNode,
char **  papszSrcValues,
char **  papszDstValues,
int  nStepSize = 1,
int  bChildOfHit = FALSE 
)

Remap node values matching list.

Remap the value of this node or any of it's children if it matches one of the values in the source list to the corresponding value from the destination list. If the pszNode value is set, only do so if the parent node matches that value. Even if a replacement occurs, searching continues.

Parameters
pszNodeRestrict remapping to children of this type of node (e.g. "PROJECTION")
papszSrcValuesa NULL terminated array of source string. If the node value matches one of these (case insensitive) then replacement occurs.
papszDstValuesan array of destination strings. On a match, the one corresponding to a source value will be used to replace a node.
nStepSizeincrement when stepping through source and destination arrays, allowing source and destination arrays to be one interleaved array for instances. Defaults to 1.
bChildOfHitOnly TRUE if we the current node is the child of a match, and so needs to be set. Application code would normally pass FALSE for this argument.
Returns
returns OGRERR_NONE unless something bad happens. There is no indication returned about whether any replacement occurred.
OGR_SRSNode * OGR_SRSNode::Clone ( ) const

Make a duplicate of this node, and it's children.

Returns
a new node tree, which becomes the responsibility of the caller.
void OGR_SRSNode::DestroyChild ( int  iChild)

Remove a child node, and it's subtree.

Note that removing a child node will result in children after it being renumbered down one.

Parameters
iChildthe index of the child.
OGRErr OGR_SRSNode::exportToPrettyWkt ( char **  ppszResult,
int  nDepth = 1 
) const

Convert this tree of nodes into pretty WKT format.

Note that the returned WKT string should be freed with CPLFree() when no longer needed. It is the responsibility of the caller.

Parameters
ppszResultthe resulting string is returned in this pointer.
nDepthdepth of the node
Returns
currently OGRERR_NONE is always returned, but the future it is possible error conditions will develop.
OGRErr OGR_SRSNode::exportToWkt ( char **  ppszResult) const

Convert this tree of nodes into WKT format.

Note that the returned WKT string should be freed with CPLFree() when no longer needed. It is the responsibility of the caller.

Parameters
ppszResultthe resulting string is returned in this pointer.
Returns
currently OGRERR_NONE is always returned, but the future it is possible error conditions will develop.
int OGR_SRSNode::FindChild ( const char *  pszValueIn) const

Find the index of the child matching the given string.

Note that the node value must match pszValue with the exception of case. The comparison is case insensitive.

Parameters
pszValueInthe node value being searched for.
Returns
the child index, or -1 on failure.
OGRErr OGR_SRSNode::FixupOrdering ( )

Correct parameter ordering to match CT Specification.

Some mechanisms to create WKT using OGRSpatialReference, and some imported WKT fail to maintain the order of parameters required according to the BNF definitions in the OpenGIS SF-SQL and CT Specifications. This method attempts to massage things back into the required order.

This method will reorder the children of the node it is invoked on and then recurse to all children to fix up their children.

Returns
OGRERR_NONE on success or an error code if something goes wrong.
OGR_SRSNode * OGR_SRSNode::GetChild ( int  iChild)

Fetch requested child.

Parameters
iChildthe index of the child to fetch, from 0 to GetChildCount() - 1.
Returns
a pointer to the child OGR_SRSNode, or NULL if there is no such child.
const OGR_SRSNode * OGR_SRSNode::GetChild ( int  iChild) const

Fetch requested child.

Parameters
iChildthe index of the child to fetch, from 0 to GetChildCount() - 1.
Returns
a pointer to the child OGR_SRSNode, or NULL if there is no such child.
int OGR_SRSNode::GetChildCount ( ) const
inline

Get number of children nodes.

Returns
0 for leaf nodes, or the number of children nodes.
OGR_SRSNode * OGR_SRSNode::GetNode ( const char *  pszName)

Find named node in tree.

This method does a pre-order traversal of the node tree searching for a node with this exact value (case insensitive), and returns it. Leaf nodes are not considered, under the assumption that they are just attribute value nodes.

If a node appears more than once in the tree (such as UNIT for instance), the first encountered will be returned. Use GetNode() on a subtree to be more specific.

Parameters
pszNamethe name of the node to search for.
Returns
a pointer to the node found, or NULL if none.
const OGR_SRSNode * OGR_SRSNode::GetNode ( const char *  pszName) const

Find named node in tree.

This method does a pre-order traversal of the node tree searching for a node with this exact value (case insensitive), and returns it. Leaf nodes are not considered, under the assumption that they are just attribute value nodes.

If a node appears more than once in the tree (such as UNIT for instance), the first encountered will be returned. Use GetNode() on a subtree to be more specific.

Parameters
pszNamethe name of the node to search for.
Returns
a pointer to the node found, or NULL if none.
const char * OGR_SRSNode::GetValue ( ) const
inline

Fetch value string for this node.

Returns
A non-NULL string is always returned. The returned pointer is to the internal value of this node, and should not be modified, or freed.
OGRErr OGR_SRSNode::importFromWkt ( char **  ppszInput)

Import from WKT string.

This method will wipe the existing children and value of this node, and reassign them based on the contents of the passed WKT string. Only as much of the input string as needed to construct this node, and it's children is consumed from the input string, and the input string pointer is then updated to point to the remaining (unused) input.

Parameters
ppszInputPointer to pointer to input. The pointer is updated to point to remaining unused input text.
Returns
OGRERR_NONE if import succeeds, or OGRERR_CORRUPT_DATA if it fails for any reason.
void OGR_SRSNode::InsertChild ( OGR_SRSNode poNew,
int  iChild 
)

Insert the passed node as a child of target node, at the indicated position.

Note that ownership of the passed node is assumed by the node on which the method is invoked ... use the Clone() method if the original is to be preserved. All existing children at location iChild and beyond are push down one space to make space for the new child.

Parameters
poNewthe node to add as a child.
iChildposition to insert, use 0 to insert at the beginning.
int OGR_SRSNode::IsLeafNode ( ) const
inline

Return whether this is a leaf node.

Returns
TRUE or FALSE
void OGR_SRSNode::MakeValueSafe ( )

Massage value string, stripping special characters so it will be a database safe string.

The operation is also applies to all subnodes of the current node.

void OGR_SRSNode::SetValue ( const char *  pszNewValue)

Set the node value.

Parameters
pszNewValuethe new value to assign to this node. The passed string is duplicated and remains the responsibility of the caller.
void OGR_SRSNode::StripNodes ( const char *  pszName)

Strip child nodes matching name.

Removes any descendant nodes of this node that match the given name. Of course children of removed nodes are also discarded.

Parameters
pszNamethe name for nodes that should be removed.

The documentation for this class was generated from the following files:

Generated for GDAL by doxygen 1.8.8.