HtmlToXml Lianja Reference Documentation

HtmlToXml

Current Version: 11.5.0

Chilkat.HtmlToXml

Convert HTML into well-formed XML for structured parsing and searching.

Chilkat.HtmlToXml converts HTML into well-formed XML so the content can be parsed, searched, transformed, or processed programmatically with XML tools. It can accept HTML from strings, files, byte arrays, BinData, or StringBuilder, and provides options for dropping selected tags, removing common text-formatting tags, controlling non-breaking spaces, choosing the XML charset, and saving the converted XML to a file.

HTML to XML conversion

Convert real-world HTML into well-formed XML that can be loaded into Chilkat.Xml or other XML processing tools.

Flexible input sources

Supply HTML from strings, files, byte arrays, BinData, or StringBuilder depending on how the content is received or built.

Drop selected tags

Remove specific tag types from the output when the application wants a cleaner XML result focused on relevant content.

Text-formatting cleanup

Drop common formatting tags when the structure matters more than visual presentation.

NBSP handling

Control how non-breaking spaces are represented, converted, removed, or preserved in the XML output.

Charset and file output

Choose the XML charset and write the converted XML directly to a file when a persisted result is needed.

Common pattern: Load or assign the HTML, set any cleanup options such as dropped tags, text-formatting removal, Nbsp behavior, and XmlCharset, then call the conversion method and parse the result as XML. Use HtmlToXml when structured extraction is needed; use HtmlToText when the goal is readable plain text.

Object Creation

loObject = createobject("CkHtmlToXml")

Properties

DebugLogFilePath
DebugLogFilePath As Character

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

  • A timeout property set to 0, indicating an infinite timeout.
  • A hang occurring within an event callback in the application code.
  • An internal bug in the Chilkat code causing the hang.

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DropCustomTags
DropCustomTags As Boolean

Controls whether tags that Chilkat does not recognize as standard HTML elements are omitted from the generated XML.

When to use: Set this property to .T. when custom or application-specific tags would add noise to the XML structure. Leave it .F. when those tags are meaningful to the application and should remain represented in the converted output.

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Html
Html As Character

The HTML source to be converted. Set this property to an HTML string, configure any conversion options, and then call ToXml, Xml, or ToXmlSb.

Assigning this property replaces the current in-memory HTML source. For file-to-file conversion, use ConvertFile. To load HTML from a file, BinData, or StringBuilder, use the corresponding SetHtml* method.

HTML input does not need to already be valid XML. The converter is intended for real-world HTML and repairs markup as needed to produce a well-formed XML document. Chilkat examples show malformed HTML being normalized and ordinary text represented in <text> elements to simplify programmatic extraction.

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LastErrorHtml
LastErrorHtml As Character (read-only)

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorText
LastErrorText As Character (read-only)

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorXml
LastErrorXml As Character (read-only)

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastMethodSuccess
LastMethodSuccess As Boolean

Indicates the success or failure of the most recent method call: .T. means success, .F. means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

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Nbsp
Nbsp As Numeric

Controls how HTML non-breaking-space entities are handled during conversion. The default value is 0.

ValueBehavior for &nbsp;
0Convert to a normal space character (U+0020).
1Convert to the numeric character reference &#160; (U+00A0).
2Drop the non-breaking-space entity.
3Leave the &nbsp; entity unconverted by this option.

This setting applies specifically to the HTML entity &nbsp;; it does not define general whitespace normalization.

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VerboseLogging
VerboseLogging As Boolean

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

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Version
Version As Character (read-only)

Version of the component/library, such as "10.1.0"

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XmlCharset
XmlCharset As Character

Specifies the character encoding to identify for the generated XML, such as utf-8 or iso-8859-1. If this property is empty, Chilkat uses the character encoding of the HTML input. Otherwise, the converted XML uses the specified charset.

String versus file output: A string returned by ToXml or Xml is a string in the programming language's native string representation, while the XML declaration reflects XmlCharset. When writing that string to a file, use the same charset so the file bytes agree with the XML declaration. ConvertFile performs the file conversion directly.

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Methods

ConvertFile
ConvertFile(inHtmlPath As Character, destXmlPath As Character) As Boolean

Converts the HTML file at inHtmlPath to a well-formed XML file at destXmlPath. The output encoding is controlled by XmlCharset; if XmlCharset is empty, Chilkat uses the HTML source encoding.

Returns .T. on success and .F. on failure.

Conversion behavior: The input is parsed as HTML rather than XML. Chilkat can normalize malformed or incomplete HTML markup as part of producing a well-formed XML document suitable for subsequent parsing and data extraction.

Returns .T. for success, .F. for failure.

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DropTagType
DropTagType(tagName As Character)

Marks the specified HTML tag type to be dropped from the generated XML. To drop multiple tag types, call this method once for each tag name.

The setting remains in effect for subsequent conversions performed by this HtmlToXml object. Use UndropTagType to reverse the setting for a particular tag type.

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DropTextFormattingTags
DropTextFormattingTags()

Configures the converter to drop common text-formatting tags from the generated XML. The affected tag names are:

b, font, i, u, br, center, em, strong, big, tt, s, small, strike, sub, and sup.

This is useful when the formatting markup is not relevant to later XML parsing and the application wants a simpler structural representation. Call UndropTextFormattingTags to keep these tags instead.

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SetHtmlBd
SetHtmlBd(bd As CkBinData) As Boolean
Introduced in version 9.5.0.77

Replaces the current HTML source with the complete contents of bd.

The data is copied from the supplied BinData object and becomes the input for a later call to ToXml, Xml, or ToXmlSb. Returns .T. on success and .F. on failure.

Returns .T. for success, .F. for failure.

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SetHtmlFromFile
SetHtmlFromFile(filename As Character) As Boolean

Loads HTML from filename and replaces the current Html input with the file contents.

Returns .T. on success and .F. if the file cannot be read or the HTML input cannot be loaded. Call ToXml, Xml, or ToXmlSb afterward to perform the conversion.

Returns .T. for success, .F. for failure.

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SetHtmlSb
SetHtmlSb(sb As CkStringBuilder) As Boolean
Introduced in version 9.5.0.97

Replaces the current HTML source with the complete contents of sb.

The text is copied from the supplied StringBuilder and becomes the input for a later call to ToXml, Xml, or ToXmlSb. Returns .T. on success and .F. on failure.

Returns .T. for success, .F. for failure.

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ToXml
ToXml() As Character

Converts the current Html input to well-formed XML and returns the XML string. The generated XML uses the conversion settings currently configured on this object, including DropCustomTags, dropped tag types, Nbsp, and XmlCharset.

HTML normalization: The input is parsed as HTML, so it does not need to already be well-formed XML. Chilkat can repair incomplete or malformed markup. The generated document is wrapped in a root element, and Chilkat represents ordinary text content in <text> elements to make extraction with XML tools straightforward.

Returns .F. on failure

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ToXmlSb
ToXmlSb(sb As CkStringBuilder) As Boolean
Introduced in version 9.5.0.77

Converts the current Html input to well-formed XML and appends the generated XML to sb.

Returns .T. on success and .F. on failure. Because the result is appended, clear the destination StringBuilder first when replacement rather than concatenation is desired.

Returns .T. for success, .F. for failure.

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UndropTagType
UndropTagType(tagName As Character)

Reverses a previous DropTagType setting for the specified tag name so that tag type is no longer intentionally dropped from subsequent XML output.

This affects only the named tag type. Other tag types previously configured to be dropped remain unchanged.

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UndropTextFormattingTags
UndropTextFormattingTags()

Configures the converter to retain the common text-formatting tags that are otherwise dropped by default:

b, font, i, u, br, center, em, strong, big, tt, s, small, strike, sub, and sup.

Call DropTextFormattingTags to return to dropping these formatting tags.

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Deprecated

ReadFileToString
ReadFileToString(filename As Character, srcCharset As Character) As Character
This method is deprecated.

Reads the complete text file at filename and decodes its bytes using srcCharset, such as utf-8 or iso-8859-1. Returns the decoded text string.

Deprecated: This convenience method is retained for compatibility with older code. It is separate from HTML-to-XML conversion; calling it does not set the Html property or perform a conversion.

Returns .F. on failure

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WriteStringToFile
WriteStringToFile(stringToWrite As Character, filename As Character, charset As Character) As Boolean
This method is deprecated.

Encodes stringToWrite using charset and writes the resulting text to filename. Typical charset names include utf-8 and iso-8859-1.

Returns .T. on success and .F. on failure.

Deprecated: This convenience method is retained for compatibility with older code. If it is used to save the string returned by ToXml, use a charset that agrees with the XML declaration, normally the same value configured in XmlCharset.

Returns .T. for success, .F. for failure.

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