node_util.h File Reference

experimental hl7 editing methods More...

#include "util.h"
#include "address.h"
#include "node.h"
#include "buffer.h"

Include dependency graph for node_util.h:

Go to the source code of this file.

Functions
int	node_append_child (node_t *parent, node_t *node)
	append child More...
node_t *	node_insert_child_at (node_t *parent, node_t *child, int pos)
	unimplemented: set a child at the sold position More...
int	node_remove (node_t *node)
	unimplemented: remove a node More...
node_t *	node_remove_child (node_t *parent, node_t *child, int pos)
	unimplemented: remove a child from the children array More...
node_t *	node_create_n_append (node_t *parent)
	create and append and empty child node More...
node_t *	node_pad_children (node_t *parent, int count)
	create empty child nodes until count is reached More...
node_t *	node_create_empty (node_type_t type)
	create an empty node More...
unsigned char *	node_to_string (node_t *node, hl7_meta_t *meta, int *length)
	convert node structure into string More...
int	message_to_file (message_t *message, char *filename)
	write contents of message to file More...
unsigned char *	message_to_string (message_t *message)
	convert message structure to hl7 file More...
int	node_set_data (node_t *node, unsigned char *data, int length)
	update date of a node More...
int	node_set_string (node_t *node, char *data)
	set string data to node More...
int	node_get_by_addr (message_t *message, hl7_addr_t *addr, node_t **node)
	find a node by address More...
int	node_set_by_addr (message_t *message, hl7_addr_t *addr, unsigned char *value, int length)
	set a value by address More...

Detailed Description

experimental hl7 editing methods

Node manipulation utilities

Note

this is work in progress and by no means complete nor stable

Function Documentation

message_to_file()

int message_to_file	(	message_t *	message,
		char *	filename
	)

write contents of message to file

same as message_to_string() but writing to a file directly.

This message returns the bytes writte on sucess or a negative integer on error.

Error codes:

• -1: failed to open file for writing
• -2: failed to convert segment to string

See also

message_to_string()

Parameters

message	input to convert to string and write to file
filename	string to file name where result shall be written

Returns

0 on succes, error otherwise

message_to_string()

unsigned char* message_to_string

(

message_t *

message

)

convert message structure to hl7 file

returns a string containing all segments covnerted to string, separated by delimiters defined in meta.

If you want to use different line or field separators, you may change these in meta before passing it into this method.

This method will return a string buffer on success, or NULL on error.

Parameters

message

input to convert to string

Returns

NULL on error else array buffer containing the hl7 file content

node_append_child()

int node_append_child	(	node_t *	parent,
		node_t *	node
	)

append child

See also

node_append()

Parameters

parent	the parent node to append a child to
node	the ndoe to append to parent

Returns

0 on success or error code otherwise

Node manipulation utilities

node_create_empty()

node_t* node_create_empty

(

node_type_t

type

)

create an empty node

for type FIELDIST, always create at least one field child node.

Note

returns NULL on FIELDLIST which seems a bit strange.

Deprecated:

this interface makes no sense, it's a duplicate of create_node_t() with a better name

Parameters

type	node type to create

Returns

new node

node_create_n_append()

node_t* node_create_n_append

(

node_t *

parent

)

create and append and empty child node

Special treatement for FIELDLIST, a FIELD node is always appended and returned.

Parameters

parent

the parent node to append a child to

Returns

new node

node_get_by_addr()

int node_get_by_addr	(	message_t *	message,
		hl7_addr_t *	addr,
		node_t **	node
	)

find a node by address

The address of the found node will be set in the 3rd parameter. If the node could not be found, the return value will currespond to the node level where we could not find anything.

Let's say, the segment does not exist, then we return SEGMENT. If the fieldlist is shorter than addr->fieldlist, then we return FIELDLIST, etc.

Return codes: if the node cannot be found, the return code will correspond to the node type where we faild to traverse.

Parameters

message	root node
addr	address to search for
node	this pointer contains the result node or NULL if not found

Returns

If found, we return 0 and *node will point to the found node

node_insert_child_at()

node_t* node_insert_child_at	(	node_t *	parent,
		node_t *	child,
		int	pos
	)

unimplemented: set a child at the sold position

This function set a child at pos.

We have cases to handle

• num_children-1 < pos: pad children with empty nodes first, return NULL
• num_children-1 >= pos: replace existing node and return pointer to old node

Todo:

unimplemented!

Todo:

The caller must take care to deallocate the replaced node. This is a bit dangerous, maybe it should be done here.

Parameters

parent	the parent node to append a child to
child	the ndoe to append to parent
pos	insert at this position

Returns

new node

node_pad_children()

node_t* node_pad_children	(	node_t *	parent,
		int	count
	)

create empty child nodes until count is reached

pad the children array until count is reached. care must be taken with node type NODELIST which should always get a single empty child in the node list iself.

See also

node_create_n_append()

Parameters

parent	parent node
count	number to pad children to

Returns

last child added

node_remove()

int node_remove

(

node_t *

node

)

unimplemented: remove a node

this method will check parent and remove the reference from the children array, moving all elements after the removed one 1 slot to the front.

All child nodes (if any) are also deleted.

Todo:

unimplemented!

Note

define a struct, where poitners to empty nodes are kept. so we can detect if a user tries to access it later. remove data, keep structure.

See also

node_remove_child()

Parameters

node	to remove from tree

node_remove_child()

node_t* node_remove_child	(	node_t *	parent,
		node_t *	child,
		int	pos
	)

unimplemented: remove a child from the children array

find node, move all subsequent children one slot to the left, adjust num_children and return a reference to the removed node for de-allocation or further use.

Todo:

unimplemented!

Parameters

parent	the parent node to append a child to
child	the ndoe to append to parent
pos	insert at this position

node_set_by_addr()

int node_set_by_addr	(	message_t *	message,
		hl7_addr_t *	addr,
		unsigned char *	value,
		int	length
	)

set a value by address

This method creates a node structure if it does not exist.

Then it sets the value to the provided value.

If the node already existed, the method will destroy (deallocate) the old node and replace it with the new one.

return codes:

• 1: Failed to allocate fieldlist
• 2: Failed to allocate field
• 3: Failed to set data on field
• 4: Failed to pad children on field (Comp)
• 5: Failed to set data on comp
• 6: Failed to pad children on field (subcmp)
• 7: Failed to set data on subcomp
• 21: tryed to add a component to a field that already has data
• 22: tryed to add a sub-component to a component that already has data

Parameters

message	root node to traverse to
addr	address of the new node
value	array of the new node's content
length	of value

Returns

0 on success, error code otherwise

node_set_data()

int node_set_data	(	node_t *	node,
		unsigned char *	data,
		int	length
	)

update date of a node

Checks and frees already associated data.

Then allocates memory for the data and assoiates it with the node, length is udpated (length is the actual length, if you are setting a string, you have to count the \0 as well).

Parameters

node
data	array buffer to set data of node to
length	of the array buffer

Returns

0 on succes, -1 when memory could not be allocated

node_set_string()

int node_set_string	(	node_t *	node,
		char *	data
	)

set string data to node

convenience function for node_set_data(). This method takes care of tracking the data length. It will copy all data up until the first \0 character).

Parameters

node
data

Returns

0 on succes, -1 when memory could not be allocated

node_to_string()

unsigned char* node_to_string	(	node_t *	node,
		hl7_meta_t *	meta,
		int *	length
	)

convert node structure into string

This method concatenates a whole tree into a string. It can be used anywhere in the tree structure from SEGMENT downwards.

If you want to use specific delimiters, make sure to create a custom meta_t structure. Otherwise (using default delimiter as of HL7 specification) just provice a default created with init_hl7_meta_t().

The length of the string is returned in the pointer of parameter 3 length, however, the return string os \0 delimited.

Parameters

node	root node
meta	delimiter definitions
length	returns the length of the output string

Returns

string representation of node tree