HtmlToXml C Reference Documentation

HtmlToXml

Current Version: 9.5.0.98

Requires Chilkat Bundle License

Class for converting HTML to well-formed XML for the purpose of programmatically extracting (scraping) information from any HTML page.

Create/Dispose

HCkHtmlToXml instance = CkHtmlToXml_Create();
// ...
CkHtmlToXml_Dispose(instance);

HCkHtmlToXml CkHtmlToXml_Create(void);

Creates an instance of the HCkHtmlToXml object and returns a handle ("void *" pointer). The handle is passed in the 1st argument for the functions listed on this page.

void CkHtmlToXml_Dispose(HCkHtmlToXml handle);

Objects created by calling CkHtmlToXml_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function. Also, any handle returned by a Chilkat "C" function must also be freed by the application by calling the appropriate Dispose method, such as CkHtmlToXml_Dispose.

Properties

DebugLogFilePath

void CkHtmlToXml_getDebugLogFilePath(HCkHtmlToXml cHandle, HCkString retval);
void CkHtmlToXml_putDebugLogFilePath(HCkHtmlToXml cHandle, const char *newVal);
const char *CkHtmlToXml_debugLogFilePath(HCkHtmlToXml cHandle);

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
there is an internal problem (bug) in the Chilkat code that causes the hang.

More Information and Examples

Example showing how to use DebugLogFilePath.

DropCustomTags

BOOL CkHtmlToXml_getDropCustomTags(HCkHtmlToXml cHandle);
void CkHtmlToXml_putDropCustomTags(HCkHtmlToXml cHandle, BOOL newVal);

If set to true, then any non-standard HTML tags will be dropped when converting to XML.

Html

void CkHtmlToXml_getHtml(HCkHtmlToXml cHandle, HCkString retval);
void CkHtmlToXml_putHtml(HCkHtmlToXml cHandle, const char *newVal);
const char *CkHtmlToXml_html(HCkHtmlToXml cHandle);

The HTML to be converted by the ToXml method. To convert HTML to XML, first set this property to the HTML string and then call ToXml. The ConvertFile method can do file-to-file conversions.

LastErrorHtml

void CkHtmlToXml_getLastErrorHtml(HCkHtmlToXml cHandle, HCkString retval);
const char *CkHtmlToXml_lastErrorHtml(HCkHtmlToXml cHandle);

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

LastErrorText

void CkHtmlToXml_getLastErrorText(HCkHtmlToXml cHandle, HCkString retval);
const char *CkHtmlToXml_lastErrorText(HCkHtmlToXml cHandle);

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

More Information and Examples

Concept of LastErrorText LastErrorText Standard Information

LastErrorXml

void CkHtmlToXml_getLastErrorXml(HCkHtmlToXml cHandle, HCkString retval);
const char *CkHtmlToXml_lastErrorXml(HCkHtmlToXml cHandle);

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

LastMethodSuccess

BOOL CkHtmlToXml_getLastMethodSuccess(HCkHtmlToXml cHandle);
void CkHtmlToXml_putLastMethodSuccess(HCkHtmlToXml cHandle, BOOL newVal);

Indicate whether the last method call succeeded or failed. A value of TRUE indicates success, a value of FALSE indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

Any method that returns a string.
Any method returning a Chilkat object, binary bytes, or a date/time.
Any method returning a standard boolean status value where success = TRUE and failure = FALSE.
Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to TRUE. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

Nbsp

int CkHtmlToXml_getNbsp(HCkHtmlToXml cHandle);
void CkHtmlToXml_putNbsp(HCkHtmlToXml cHandle, int newVal);

Determines how to handle HTML entities. The default value, 0 will cause   entites to be convert to normal space characters (ASCII value 32). If this property is set to 1, then  's will be converted to &#160. If set to 2, then &nbps;'s are dropped. If set to 3, then &nbsp's are left unmodified.

Utf8

BOOL CkHtmlToXml_getUtf8(HCkHtmlToXml cHandle);
void CkHtmlToXml_putUtf8(HCkHtmlToXml cHandle, BOOL newVal);

When set to TRUE, all "const char *" arguments are interpreted as utf-8 strings. If set to FALSE (the default), then "const char *" arguments are interpreted as ANSI strings. Also, when set to TRUE, and Chilkat method returning a "const char *" is returning the utf-8 representation. If set to FALSE, all "const char *" return values are ANSI strings.

VerboseLogging

BOOL CkHtmlToXml_getVerboseLogging(HCkHtmlToXml cHandle);
void CkHtmlToXml_putVerboseLogging(HCkHtmlToXml cHandle, BOOL newVal);

If set to TRUE, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is FALSE. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

Version

void CkHtmlToXml_getVersion(HCkHtmlToXml cHandle, HCkString retval);
const char *CkHtmlToXml_version(HCkHtmlToXml cHandle);

Version of the component/library, such as "9.5.0.94"

More Information and Examples

How to get the Chilkat version at runtime.

XmlCharset

void CkHtmlToXml_getXmlCharset(HCkHtmlToXml cHandle, HCkString retval);
void CkHtmlToXml_putXmlCharset(HCkHtmlToXml cHandle, const char *newVal);
const char *CkHtmlToXml_xmlCharset(HCkHtmlToXml cHandle);

The charset, such as "utf-8" or "iso-8859-1" of the XML to be created. If XmlCharset is empty, the XML is created in the same character encoding as the HTML. Otherwise the HTML is converted XML and converted to this charset.

Methods

ConvertFile

BOOL CkHtmlToXml_ConvertFile(HCkHtmlToXml cHandle, const char *inHtmlPath, const char *destXmlPath);

Converts an HTML file to a well-formed XML file that can be parsed for the purpose of programmatically extracting information.

Returns TRUE for success, FALSE for failure.

DropTagType

void CkHtmlToXml_DropTagType(HCkHtmlToXml cHandle, const char *tagName);

Allows for any specified tag to be dropped from the output XML. To drop more than one tag, call this method once for each tag type to be dropped.

DropTextFormattingTags

void CkHtmlToXml_DropTextFormattingTags(HCkHtmlToXml cHandle);

Causes text formatting tags to be dropped from the XML output. Text formatting tags are: b, font, i, u, br, center, em, strong, big, tt, s, small, strike, sub, and sup.

More Information and Examples

Drop/Undrop Text Formatting Tags

ReadFile

BOOL CkHtmlToXml_ReadFile(HCkHtmlToXml cHandle, const char *path, HCkByteData outBytes);

Convenience method for reading a complete file into a byte array.

Returns TRUE for success, FALSE for failure.

ReadFileToString

BOOL CkHtmlToXml_ReadFileToString(HCkHtmlToXml cHandle, const char *filename, const char *srcCharset, HCkString outStr);
const char *CkHtmlToXml_readFileToString(HCkHtmlToXml cHandle, const char *filename, const char *srcCharset);

Convenience method for reading a text file into a string. The character encoding of the text file is specified by srcCharset. Valid values, such as "iso-8895-1" or "utf-8" are listed at: List of Charsets.

Returns TRUE for success, FALSE for failure.

SetHtmlBd

BOOL CkHtmlToXml_SetHtmlBd(HCkHtmlToXml cHandle, HCkBinData bd);

Introduced in version 9.5.0.77

Sets the Html property from the contents of bd.

Returns TRUE for success, FALSE for failure.

More Information and Examples

HTML Table to CSV

SetHtmlBytes

void CkHtmlToXml_SetHtmlBytes(HCkHtmlToXml cHandle, HCkByteData inData);

Sets the Html property from a byte array.

SetHtmlFromFile

BOOL CkHtmlToXml_SetHtmlFromFile(HCkHtmlToXml cHandle, const char *filename);

Sets the Html property by loading the HTML from a file.

Returns TRUE for success, FALSE for failure.

SetHtmlSb

BOOL CkHtmlToXml_SetHtmlSb(HCkHtmlToXml cHandle, HCkStringBuilder sb);

Introduced in version 9.5.0.97

Sets the Html property from the contents of sb.

Returns TRUE for success, FALSE for failure.

ToXml

BOOL CkHtmlToXml_ToXml(HCkHtmlToXml cHandle, HCkString outStr);
const char *CkHtmlToXml_toXml(HCkHtmlToXml cHandle);

Converts the HTML in the "Html" property to XML and returns the XML string.

Returns TRUE for success, FALSE for failure.

More Information and Examples

Convert an HTML Table to Plain-Text

ToXmlSb

BOOL CkHtmlToXml_ToXmlSb(HCkHtmlToXml cHandle, HCkStringBuilder sb);

Introduced in version 9.5.0.77

Converts the HTML in the "Html" property to XML and appends the XML to sb.

Returns TRUE for success, FALSE for failure.

More Information and Examples

HTML Table to CSV

UndropTagType

void CkHtmlToXml_UndropTagType(HCkHtmlToXml cHandle, const char *tagName);

Causes a specified type of tag to NOT be dropped in the output XML.

UndropTextFormattingTags

void CkHtmlToXml_UndropTextFormattingTags(HCkHtmlToXml cHandle);

Causes text formatting tags to NOT be dropped from the XML output. Text formatting tags are: b, font, i, u, br, center, em, strong, big, tt, s, small, strike, sub, and sup.

Important: Text formatting tags are dropped by default. Call this method to prevent text formatting tags from being dropped.

More Information and Examples

Drop/Undrop Text Formatting Tags

WriteFile

BOOL CkHtmlToXml_WriteFile(HCkHtmlToXml cHandle, const char *path, HCkByteData fileData);

Convenience method for saving a byte array to a file.

Returns TRUE for success, FALSE for failure.

WriteStringToFile

BOOL CkHtmlToXml_WriteStringToFile(HCkHtmlToXml cHandle, const char *stringToWrite, const char *filename, const char *charset);

Convenience method for saving a string to a file. The character encoding of the output text file is specified by charset (the string is converted to this charset when writing). Valid values, such as "iso-8895-1" or "utf-8" are listed at: List of Charsets.

Returns TRUE for success, FALSE for failure.

Xml

BOOL CkHtmlToXml_Xml(HCkHtmlToXml cHandle, HCkString outStr);
const char *CkHtmlToXml_xml(HCkHtmlToXml cHandle);

This is the same as the "ToXml" method. It converts the HTML in the "Html" property to XML and returns the XML string.

Returns TRUE for success, FALSE for failure.