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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>`

## Classes
struct | Listener
| Listener that is notified of modification to nodes. More...

## Public Member Functions
| OGR_SRSNode (const char *=nullptr)
| Constructor.
void | RegisterListener (const std::shared_ptr< Listener > &listener)
| Register a (single) listener.
int | IsLeafNode () const
| Return whether this is a leaf node.
int | GetChildCount () const
| Get number of children nodes.
OGR_SRSNode * | GetChild (int)
| Fetch requested child.
const OGR_SRSNode * | GetChild (int) const
| Fetch requested child.
OGR_SRSNode * | GetNode (const char *)
| Find named node in tree.
const OGR_SRSNode * | GetNode (const char *) const
| Find named node in tree.
void | InsertChild (OGR_SRSNode *, int)
| Insert the passed node as a child of target node, at the indicated position.
void | AddChild (OGR_SRSNode *)
| Add passed node as a child of target node.
int | FindChild (const char *) const
| Find the index of the child matching the given string.
void | DestroyChild (int)
| Remove a child node, and it's subtree.
void | ClearChildren ()
| Clear children nodes.
void | StripNodes (const char *)
| Strip child nodes matching name.
const char * | GetValue () const
| Fetch value string for this node.
void | SetValue (const char *)
| Set the node value.
void | MakeValueSafe ()
| Massage value string, stripping special characters so it will be a database safe string.
OGR_SRSNode * | Clone () const
| Make a duplicate of this node, and it's children.
OGRErr | importFromWkt (char **)
| Import from WKT string.
OGRErr | importFromWkt (const char **)
| Import from WKT string.
OGRErr | exportToWkt (char **) const
| Convert this tree of nodes into WKT format.
OGRErr | exportToPrettyWkt (char **, int=1) const
| Convert this tree of nodes into pretty WKT format.

## 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 its data structure; however, this class is user accessible for detailed access to components of an SRS definition.

## Constructor & Destructor Documentation

## ◆ OGR_SRSNode()

OGR_SRSNode::OGR_SRSNode | ( | const char * | pszValueIn = `nullptr` | ) |
| explicit

Constructor.

Parameters

  pszValueIn | this 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

## ◆ AddChild()

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

  poNew | the node to add as a child.

## ◆ Clone()

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.

## ◆ DestroyChild()

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

  iChild | the index of the child.

## ◆ exportToPrettyWkt()

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

  ppszResult | the resulting string is returned in this pointer.
  nDepth | depth of the node

Returns
  currently OGRERR_NONE is always returned, but the future it is possible error conditions will develop.

## ◆ exportToWkt()

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

  ppszResult | the resulting string is returned in this pointer.

Returns
  currently OGRERR_NONE is always returned, but the future it is possible error conditions will develop.

## ◆ FindChild()

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

  pszValueIn | the node value being searched for.

Returns
  the child index, or -1 on failure.

## ◆ GetChild() [1/2]

OGR_SRSNode * OGR_SRSNode::GetChild | ( | int | iChild | ) |

Fetch requested child.

Parameters

  iChild | the 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.

## ◆ GetChild() [2/2]

const OGR_SRSNode * OGR_SRSNode::GetChild | ( | int | iChild | ) | const

Fetch requested child.

Parameters

  iChild | the 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.

## ◆ GetChildCount()

int OGR_SRSNode::GetChildCount | ( |  | ) | const
| inline

Get number of children nodes.

Returns
  0 for leaf nodes, or the number of children nodes.

## ◆ GetNode() [1/2]

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

  pszName | the name of the node to search for.

Returns
  a pointer to the node found, or NULL if none.

## ◆ GetNode() [2/2]

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

  pszName | the name of the node to search for.

Returns
  a pointer to the node found, or NULL if none.

## ◆ GetValue()

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.

## ◆ importFromWkt() [1/2]

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 its children is consumed from the input string, and the input string pointer is then updated to point to the remaining (unused) input.

Parameters

  ppszInput | Pointer 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.

Deprecated:
  GDAL 2.3. Use importFromWkt(const char**) instead.

## ◆ importFromWkt() [2/2]

OGRErr OGR_SRSNode::importFromWkt | ( | const 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 its children is consumed from the input string, and the input string pointer is then updated to point to the remaining (unused) input.

Parameters

  ppszInput | Pointer 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.

Since
  GDAL 2.3

## ◆ InsertChild()

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

  poNew | the node to add as a child.
  iChild | position to insert, use 0 to insert at the beginning.

## ◆ IsLeafNode()

int OGR_SRSNode::IsLeafNode | ( |  | ) | const
| inline

Return whether this is a leaf node.

Returns
  TRUE or FALSE

## ◆ MakeValueSafe()

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.

## ◆ SetValue()

void OGR_SRSNode::SetValue | ( | const char * | pszNewValue | ) |

Set the node value.

Parameters

  pszNewValue | the new value to assign to this node. The passed string is duplicated and remains the responsibility of the caller.

## ◆ StripNodes()

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

  pszName | the name for nodes that should be removed.

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

- ogr_spatialref.h
- ogr_srsnode.cpp