This class encapsulates the native OpcUa_String structure and handles memory allocation and cleanup for you. Additionally you can extract native UTF-8 (char*) strings or UTF-16 (ushort*) strings for further processing in other applications. UaString uses implicit sharing to avoid needless copying and to boost the performance. Only if you modify a shared string it creates a copy for that (copy-on-write). So assigning another UaString or passing it as parameter needs constant time is nearly as fast as assigning a pointer.
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#include <uastring.h>
List of all members.
Detailed Description
This class encapsulates the native OpcUa_String structure and handles memory allocation and cleanup for you. Additionally you can extract native UTF-8 (char*) strings or UTF-16 (ushort*) strings for further processing in other applications. UaString uses implicit sharing to avoid needless copying and to boost the performance. Only if you modify a shared string it creates a copy for that (copy-on-write). So assigning another UaString or passing it as parameter needs constant time is nearly as fast as assigning a pointer.
int foo(OpcUa_String *native)
{
UaString str(native);
UaByteArray array = str.toUtf16();
const ushort *wszUtf16 = array;
wprintf(L"%s\\n", wszUtf16);
str += "abc";
native = str.toOpcUaString();
}
Constructor & Destructor Documentation
Default constructor. Creates an empty UaString.
| UaString::UaString |
( |
const OpcUa_String * |
other ) |
|
Creates a copy of the native OpcUa_String.
- Parameters:
-
| UaString::UaString |
( |
const UaString & |
other ) |
|
Creates a copy of another UaString. This operation takes constant time, because UaString is implicitly shared. This makes returning a UaString from a function very fast. If a shared instance is modified, it will be copied (copy-on-write), and that takes linear time.
- Parameters:
-
Creates a string initialized with the byte array other. The given data is interpreted as UTF-8. Stops copying at the first 0 character, otherwise copies the entire byte array. The the array is not 0 terminated a 0 will be appended.
- Parameters:
-
| other | the byte array to copy. |
| UaString::UaString |
( |
const char * |
other ) |
|
Creates a copy of an UTF-8 encoded character string. This operation assumes that other is UTF-8 encoded. You may also pass pure ASCII strings with characters below 128. The first 128 characters from US-ASCII (Unicode range U+0000 to U+007F).are a subset of UTF-8.
UaString sample("abc");
Don't use unicode characters in hardcoded strings unless you know what you are doing. This will only work if you save your source file UTF-8 encoded.
UaString sample("öäü"); // DANGER!!!
- Parameters:
-
| UaString::UaString |
( |
const UaUShort * |
other ) |
|
Creates a copy of an UTF-16 encoded wide character string. This is typically used on Windows with wchar_t* strings.
- Parameters:
-
destruction Destroyes the string.
Member Function Documentation
Returns a copy of this string with the lowest numbered place marker replaced by string a, i.e., 1, 2, ..., 99.
- Parameters:
-
| a | String to replace the lowest numbered place marker with. |
| fieldWidth | specifies the minimum amount of space that argument a shall occupy. If a requires less space than fieldWidth, it is padded to fieldWidth with character fillChar. A positive fieldWidth produces right-aligned text. A negative fieldWidth produces left-aligned text. |
| fillChar | If a requires less space than fieldWidth, it is padded to fieldWidth with character fillChar. |
- Returns:
- Returns a copy of this string with the lowest numbered place marker replaced.
| const UaChar UaString::at |
( |
int |
i ) |
const |
Returns a read only unicode character. Because UTF-8 is from variable length you cannot simply change a character. Other may need to be moved.
- See also:
- replace()
- Parameters:
-
| i | the position of the actual char in the string. |
- Returns:
- a read only unicode character.
| OpcUa_String * UaString::clone |
( |
const OpcUa_String & |
source ) |
[static] |
This is a convenience function to clone native OpcUa_String that are used in the OPC UA ANSI Stack. This works without creating an instance of UaString.
- Parameters:
-
| source | The source string to clone. |
- Returns:
- A new OpcUa_String copy. You are responsible for deleting this string.
| void UaString::cloneTo |
( |
const OpcUa_String & |
source, |
|
|
OpcUa_String & |
copy |
|
) |
| [static] |
This is a convenience function and behaves like the function above. The difference is, that is copies the string into an existing OpcUa_String instead of allocating a new structure. This may be used to fill an OpcUa_String that is embedded into another structure.
- Parameters:
-
| source | he source string to clone. |
| copy | The destination string to copy the string contents to. |
| OpcUa_String * UaString::copy |
( |
) |
const |
Creates an independent copy of this string as OpcUa_String. Use this function if you need a copy of this string that is freed from the Opc Ua stack. The returned string must be freed with OpcUa_String_Delete.
- Returns:
- an independent copy of this string as OpcUa_String.
| void UaString::copyTo |
( |
OpcUa_String * |
pDst ) |
const |
Copies the string contents into an existing OpcUa_String. Use this function if you need to fill an OpcUa_String that is nested in another Opc Ua structure.
Example:
UaString sNodeId("Path/to/Node");
OpcUa_NodeId id;
id.IdentifierType = OpcUa_IdentifierType_String;
sNodeId.copyTo(&id.Identifier.String);
- Parameters:
-
| pDst | the destination of this copyoperation. |
| int UaString::find |
( |
UaChar |
cFind, |
|
|
unsigned int |
iStart |
|
) |
| const |
Finds the position of an UTF-8 character in the string after start index.
- Parameters:
-
| cFind | the char to find the position of. |
| iStart | the start position to find the char. |
- Returns:
- the position of an UTF-8 character in the string after start index.
| int UaString::find |
( |
UaChar |
cFind ) |
const |
Finds the position of an UTF-8 character in the string.
- Parameters:
-
| cFind | the char to find the position of. |
- Returns:
- the position of an UTF-8 character in the string or -1 if the character is not found.
| bool UaString::isEmpty |
( |
) |
const |
Returns true if the string is empty. This function will return true for a null string.
- Returns:
- true if the string is empty.
| bool UaString::isLikePatternValid |
( |
const UaString & |
pattern ) |
[static] |
Tests if a given Like-Pattern is valid or not.
- Parameters:
-
| pattern | the Like-Pattern to test. |
- Returns:
- True if the pattern is valid, otherwise false.
| bool UaString::isNull |
( |
) |
const |
Returns true if the string is null. This function will return false for an empty string.
- Returns:
- true if the string is null.
| int UaString::length |
( |
) |
const |
Returns the number of characters of this string. You will need this function for displaying it. With UTF-8 strings the number of characters and the size in bytes may differ
- Returns:
- the number of characters of this string.
| bool UaString::like |
( |
const UaString & |
pattern ) |
const |
Implements the Like-Operator of the UA-Specification. Checks if the given pattern matches the string.
- Parameters:
-
| pattern | the Like-Pattern to use. |
- Returns:
- True if the pattern matches the string, otherwise false.
| UaString UaString::number |
( |
int |
n, |
|
|
int |
base = 10 |
|
) |
| [static] |
Returns a string equivalent of the number n to base base, which is 10 by default and must be between 2 and 36.
- Parameters:
-
| n | a signed int number to convert to a string |
| base | the base for interpreting the number |
| UaString UaString::number |
( |
unsigned int |
n, |
|
|
int |
base = 10 |
|
) |
| [static] |
Returns a string equivalent of the number n to base base, which is 10 by default and must be between 2 and 36.
- Parameters:
-
| n | a unsigned int number to convert to a string |
| base | the base for interpreting the number |
| UaString::operator const OpcUa_String * |
( |
) |
const |
This implicitly casts this string to an OpcUa_String to be able to pass it to low level Opc Ua stack functions. The result remains valid until the string is modified.
- See also:
- toOpcUaString
- Returns:
- an OpcUa_String to be able to pass it to low level Opc Ua stack functions.
| bool UaString::operator!= |
( |
const UaString & |
other ) |
const |
Returns true if other is not equal to this.
- See also:
- operator==
- Parameters:
-
- Returns:
- true if other is not equal to this.
Addition operator.
- Parameters:
-
- Returns:
- Addition operator.
Appends a sring to the internal string. This creates a copy of the string because the internal data needs to changed.
- Parameters:
-
- Returns:
- a sring to the internal string.
| bool UaString::operator< |
( |
const UaString & |
other ) |
const |
This operator is mainly used to sort strings. That is e.g. necesarry to use it as a key in a binary tree.
- Parameters:
-
- Returns:
- operator is mainly used to sort strings.
Assigns other to this string and returns a reference to this string.
- Parameters:
-
- Returns:
- a reference to this string.
| bool UaString::operator== |
( |
const UaString & |
other ) |
const |
Returns true if other is equal to this.
- See also:
- operator!=
- Parameters:
-
- Returns:
- true if other is equal to this.
| int UaString::size |
( |
) |
const |
Returns the size in bytes that the internal UTF-8 representation needs to hold this string. You will only need this function, if you want to allocate a native UTF-8 string that should be big enough to hold this string.
- Returns:
- the size in bytes that the internal UTF-8 representation needs to hold this string.
| const OpcUa_String * UaString::toOpcUaString |
( |
) |
const |
Returns an OpcUa_String to be able to pass this string to low level Opc Ua stack functions. The result remains valid until the string is modified.
- Returns:
- an OpcUa_String to be able to pass this string to low level Opc Ua stack functions.
Returns a UTF-16 representation of the string as a UaByteArray. This creates a copy of the string because the internal data needs to be converted. UaByteArray takes care of the memory.
Make sure you are always using the function together with a cast to const UaUShort* to make sure you get the right format extracted if you need a wchar_t*.
Example:
wchar_t str[512];
UaString sString("Test String");
// Wrong use
swprintf_s(str, 512, L"String:%s", sString.toUtf16());
// str = String:
// Right use
swprintf_s(str, 512, L"String:%s", (const UaUShort*)sString.toUtf16());
// str = String:Test String
- Returns:
- a UTF-16 representation of the string as a UaByteArray.
| const char * UaString::toUtf8 |
( |
) |
const |
Returns the string as a '\0'-terminated array of characters. The result remains valid until the string is modified
- Returns:
- the string as a '\0'-terminated array of characters.
The documentation for this class was generated from the following files:
- /home/buildbot/work/uasdkcpp/src/uabase/uabasecpp/uastring.h
- /home/buildbot/work/uasdkcpp/src/uabase/uabasecpp/uastring.cpp
