HtmlToText SQL Server Reference Documentation

HtmlToText

Current Version: 11.6.0

Chilkat.HtmlToText

Convert HTML into readable plain text with control over links, wrapping, and encoding.

Chilkat.HtmlToText converts HTML content into readable plain text. It can decode HTML entities, wrap output at a configurable right margin, optionally include or suppress hyperlink URLs, convert HTML supplied as a string or StringBuilder, and read or write files using an explicit character encoding.

HTML to plain text

Convert HTML markup into readable text suitable for display, logging, indexing, email alternatives, or text-only output.

Entity decoding

Decode HTML entities so text such as named entities and numeric character references becomes normal readable output.

Line wrapping

Use RightMargin to wrap text at a chosen width, or set it to 0 when no right-margin wrapping is wanted.

Link handling

Suppress hyperlink URLs for cleaner text, or emit URLs when the output needs to preserve the destination of HTML links.

StringBuilder support

Convert HTML directly from a StringBuilder when working with larger or incrementally built HTML content.

File and charset helpers

Read HTML from files and write text output using a specified character encoding.

Common pattern: Provide the HTML as a string, file, or StringBuilder, choose whether to decode entities and include link URLs, set the desired right margin, then convert the result to plain text. Use HtmlToText when the goal is readable text, not structured XML or DOM-style parsing.

Object Creation

DECLARE @hr int
DECLARE @htmlToText int
EXEC @hr = sp_OACreate 'Chilkat.HtmlToText', @htmlToText OUT
IF @hr <> 0
BEGIN
    PRINT 'Failed to create ActiveX component'
    RETURN
END

-- ... use @htmlToText ...

EXEC @hr = sp_OADestroy @htmlToText

T-SQL uses the Chilkat ActiveX through the OLE Automation stored procedures. They must be enabled once on the server (EXEC sp_configure 'Ole Automation Procedures', 1; RECONFIGURE;), and the Chilkat ActiveX registered must match the bitness of the SQL Server instance (64-bit for a 64-bit SQL Server). To bind to a specific major version of Chilkat, append the major version number to the ProgID, such as sp_OACreate 'Chilkat.HtmlToText.11' for Chilkat v11.*.*.

sp_OACreate returns an object token (an int) that is passed as the first argument of every sp_OAMethod, sp_OAGetProperty and sp_OASetProperty call, and released with sp_OADestroy. Objects returned by methods (such as an HttpResponse or JsonObject) are also tokens received through an int OUT parameter; they must likewise be destroyed, and the OUT parameter is NULL when the method fails to return an object. Objects passed as arguments are passed by their token. When an OLE Automation procedure itself fails (non-zero @hr), sp_OAGetErrorInfo describes the error.

Data types: strings are nvarchar(4000); integers, booleans (1 or 0) and object tokens are int; dates are datetime. In the signatures on this page, @success, @iResult, @sResult and the like are the OUT variables receiving a method's return value, @iValue / @sValue receive or supply a property value, and the remaining @ variables are the method's arguments in order.

A string returned through an OUT parameter is limited to 4000 characters. For longer values, retrieve the result as a result set into a table variable instead of an OUT parameter, for example DECLARE @tmp TABLE (outputLine ntext) followed by INSERT INTO @tmp EXEC sp_OAGetProperty @htmlToText, 'LastErrorText'. See string length limitations for strings returned by sp_OAMethod calls.

Methods that pass or return raw byte arrays are not shown on this page, because varbinary(max) values cannot be exchanged through sp_OAMethod (see varbinary(max) limitation). Use the BinData-based alternatives (methods ending in Bd) or the base64 / hex string-encoded variants instead. Binary properties (such as LastBinaryResult) can be retrieved as a result set into a table variable, as shown in their signatures. Asynchronous (*Async) methods and event callbacks are not available from SQL Server.

Properties

DebugLogFilePath
EXEC sp_OAGetProperty @htmlToText, 'DebugLogFilePath', @sValue OUT
EXEC sp_OASetProperty @htmlToText, 'DebugLogFilePath', @sValue

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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DecodeHtmlEntities
EXEC sp_OAGetProperty @htmlToText, 'DecodeHtmlEntities', @iValue OUT
EXEC sp_OASetProperty @htmlToText, 'DecodeHtmlEntities', @iValue

Controls whether HTML character references are decoded when converting HTML to plain text. The default value is 1.

Value Behavior
1 HTML entities and numeric character references are decoded to their corresponding characters. For example, &amp; becomes &.
0 Character references are left encoded in the plain-text output.
Typical use: Leave this property set to 1 when the goal is human-readable text. Set it to 0 when the original entity notation itself must be preserved.

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LastBinaryResult
INSERT INTO @tmp EXEC sp_OAGetProperty @htmlToText, 'LastBinaryResult'

This property is mainly used in SQL Server stored procedures to retrieve binary data from the last method call that returned binary data. It is only accessible if Chilkat.Global.KeepBinaryResult is set to 1. This feature allows for the retrieval of large varbinary results in an SQL Server environment, which has restrictions on returning large data via method calls, though temp tables can handle binary properties.

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LastErrorHtml
EXEC sp_OAGetProperty @htmlToText, 'LastErrorHtml', @sValue OUT

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
EXEC sp_OAGetProperty @htmlToText, 'LastErrorText', @sValue OUT

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
EXEC sp_OAGetProperty @htmlToText, 'LastErrorXml', @sValue OUT

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
EXEC sp_OAGetProperty @htmlToText, 'LastMethodSuccess', @iValue OUT
EXEC sp_OASetProperty @htmlToText, 'LastMethodSuccess', @iValue

Indicates the success or failure of the most recent method call: 1 means success, 0 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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LastStringResult
EXEC sp_OAGetProperty @htmlToText, 'LastStringResult', @sValue OUT

In SQL Server stored procedures, this property holds the string return value of the most recent method call that returns a string. It is accessible only when Chilkat.Global.KeepStringResult is set to TRUE. SQL Server has limitations on string lengths returned from methods and properties, but temp tables can be used to access large strings.

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LastStringResultLen
EXEC sp_OAGetProperty @htmlToText, 'LastStringResultLen', @iValue OUT

The length, in characters, of the string contained in the LastStringResult property.

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RightMargin
EXEC sp_OAGetProperty @htmlToText, 'RightMargin', @iValue OUT
EXEC sp_OASetProperty @htmlToText, 'RightMargin', @iValue

Controls line wrapping in the generated plain text. The default value is 80. As a line approaches the configured margin, Chilkat attempts to wrap at a SPACE character. Set this property to 0 to disable right-margin wrapping.

Soft margin: The right margin is a preferred wrapping point, not a guaranteed maximum line length. A long sequence with no suitable SPACE character may extend beyond the configured margin.

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SuppressLinks
EXEC sp_OAGetProperty @htmlToText, 'SuppressLinks', @iValue OUT
EXEC sp_OASetProperty @htmlToText, 'SuppressLinks', @iValue

Controls whether hyperlink destination URLs are included in the generated plain text. The default value is 1.

Value Behavior
1 The visible anchor text is retained, but hyperlink destination URLs are omitted.
0 Hyperlink URLs are included. By default, they are collected in a References: section at the end of the plain text.
For example, with SuppressLinks set to 0, an HTML link whose visible text is chilkat and whose URL is https://www.chilkatsoft.com/ produces the visible text and a numbered reference at the end of the output.
Related options: When link URLs are enabled, UncommonOptions can be used to suppress the trailing references list with NoReferencesList or emit URLs inline with EmitUrls.

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UncommonOptions
EXEC sp_OAGetProperty @htmlToText, 'UncommonOptions', @sValue OUT
EXEC sp_OASetProperty @htmlToText, 'UncommonOptions', @sValue
Introduced in version 11.0.0

Specifies uncommon HTML-to-text conversion options as a comma-separated list of keywords. The default is the empty string, which is appropriate for normal use.

Keyword Effect
NoReferencesList Does not generate the hyperlink-reference list at the end of the plain-text output.
EmitUrls Emits hyperlink URLs inline in the plain-text output instead of relying on the default trailing reference list.
Interaction with SuppressLinks: These options control the presentation of hyperlink URLs when URL output is enabled. If SuppressLinks is 1, hyperlink URLs are suppressed.

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VerboseLogging
EXEC sp_OAGetProperty @htmlToText, 'VerboseLogging', @iValue OUT
EXEC sp_OASetProperty @htmlToText, 'VerboseLogging', @iValue

If set to 1, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is 0. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
EXEC sp_OAGetProperty @htmlToText, 'Version', @sValue OUT

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

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Methods

ToText
EXEC sp_OAMethod @htmlToText, 'ToText', @sResult OUT, @html

Converts the HTML in html to readable plain text and returns the result. The conversion honors DecodeHtmlEntities, RightMargin, SuppressLinks, and UncommonOptions. HTML markup is interpreted to produce readable text rather than simply being removed with a tag-stripping operation.

Plain-text conversion: The output is intended for reading, indexing, logging, email text alternatives, and similar text-oriented uses. It is not intended to preserve the original HTML markup or visual layout exactly.

Returns NULL on failure

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ToTextSb
EXEC sp_OAMethod @htmlToText, 'ToTextSb', @success OUT, @sb
Introduced in version 9.5.0.97

Converts the HTML currently contained in sb to plain text in place. On success, the same StringBuilder contains the converted plain-text result. The conversion honors DecodeHtmlEntities, RightMargin, SuppressLinks, and UncommonOptions.

StringBuilder workflow: Use this method when the HTML is already held in a StringBuilder and you want the conversion result returned through that same object rather than as a separate string.

Returns 1 for success, 0 for failure.

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Deprecated

ReadFileToString
EXEC sp_OAMethod @htmlToText, 'ReadFileToString', @sResult OUT, @filename, @srcCharset
This method is deprecated.

Reads an entire text file and returns its contents as a string. The srcCharset argument specifies the character encoding used to decode the file bytes, such as utf-8 or iso-8859-1.

Convenience method: This method only reads and decodes the file. It does not perform HTML-to-text conversion. A typical workflow is to read the HTML with ReadFileToString and pass the returned string to ToText.
See the List of Charsets for supported charset names.

Returns NULL on failure

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WriteStringToFile
EXEC sp_OAMethod @htmlToText, 'WriteStringToFile', @success OUT, @stringToWrite, @filename, @charset
This method is deprecated.

Writes stringToWrite to filename using the character encoding specified by charset. The string is converted to that charset as it is written. Common values include utf-8 and iso-8859-1.

Convenience method: This method performs file output only; it does not convert HTML. To save converted text, first call ToText, then pass that result to WriteStringToFile.
See the List of Charsets for supported charset names.

Returns 1 for success, 0 for failure.

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