THtmlToXml Delphi ActiveX Reference Documentation
THtmlToXml
Current Version: 10.0.0
Class for converting HTML to well-formed XML for the purpose of programmatically extracting (scraping) information from any HTML page.
Importing the Chilkat ActiveX into Delphi
Important: When upgrading to a new version of Chilkat, make sure to re-imported ActiveX DLL into Delphi to regenerate the files described below.
Chilkat v9.5.*: If using Chilkat v9.5.*, then use "Chilkat_v9_5_0_TLB" instead of "Chilkat_TLB", and the DLLs are named ChilkatAx-9.5.0-win32.dll (or ChilkatAx-9.5.0-x64.dll).
Two things are required to use an ActiveX in Delphi:
- The ActiveX DLL needs to be registered via regsvr32 on the system where the Delphi application runs. See How To Register ActiveX DLLs for detailed information.
- See also: ActiveX Registration Tutorial
- The ActiveX component needs to be "imported". Use the Delphi Import Component Wizard to import the Chilkat type library. This creates the following files: Chilkat_TLB.pas and Chilkat_TLB.dcr. The Chilkat_TLB.pas should be added to your project.
To import the Chilkat type library, do the following:
- In the Delphi RAD Studio, select the menu item "Component" --> "Import a Type Library".
- Find "Chilkat ActiveX" in the list and select it. This will only appear in the list if the ChilkatAx-win32.dll (or ChilkatAx-x64.dll) has been registered w/ regsvr32.
- Check the "Generate Component Wrappers" checkbox.
- Select a directory where the unit files (.pas and .dcr) should be generated.
- Select "Create Unit" and then "Finish".
- Add the .pas to your Delphi project.
To use a Chilkat ActiveX object in your Delphi code, add "Chilkat_TLB" to the "uses" statement. For example:
uses Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;
Object Creation
var obj: THtmlToXml; ... begin obj := THtmlToXml.Create(Self); ... // When finished, free the object instance. obj.Free();
Properties
DebugLogFilePath
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.
DropCustomTags
If set to true, then any non-standard HTML tags will be dropped when converting to XML.
topHtml
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.
topLastBinaryResult
The binary data returned by the last (binary data returning) method called. Only available if Chilkat.Global.KeepBinaryResult is set to 1. This provides a means for obtaining large varbinary results in the SQL Server environment (where limitations exist in getting large amounts of data returned by method calls, but where temp tables can be used for binary properties).
topLastErrorHtml
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.
topLastErrorText
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.
LastErrorXml
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.
topLastMethodSuccess
Indicate whether the last method call succeeded or failed. A value of 1 indicates success, a value of 0 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 = 1 and failure = 0.
- 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 1. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.
topLastStringResult
The string return value of the last (string returning) method called. Only available if Chilkat.Global.KeepStringResult is set to 1. This provides a means for obtaining large string results in the SQL Server environment (where limitations exist in getting long strings returned by method calls, but where temp tables can be used for string properties).
LastStringResultLen
The length, in characters, of the string contained in the LastStringResult property.
topNbsp
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  . If set to 2, then &nbps;'s are dropped. If set to 3, then  's are left unmodified.
topVerboseLogging
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.
topVersion
XmlCharset
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.
topMethods
ConvertFile
Converts an HTML file to a well-formed XML file that can be parsed for the purpose of programmatically extracting information.
Returns 1 for success, 0 for failure.
topDropTagType
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.
topDropTextFormattingTags
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.
ReadFile
Convenience method for reading a complete file into a byte array.
Returns a zero-length byte array (as an OleVariant) on failure.
An empty array will have a VarArrayHighBound of -1 meaning 0 elements.
ReadFileToString
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 a zero-length WideString on failure
topSetHtmlBd
Sets the Html property from the contents of bd.
Returns 1 for success, 0 for failure.
SetHtmlBytes
Sets the Html property from a byte array.
topSetHtmlFromFile
SetHtmlSb
ToXml
Converts the HTML in the "Html" property to XML and returns the XML string.
Returns a zero-length WideString on failure
ToXmlSb
Converts the HTML in the "Html" property to XML and appends the XML to sb.
Returns 1 for success, 0 for failure.
UndropTagType
Causes a specified type of tag to NOT be dropped in the output XML.
topUndropTextFormattingTags
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.
WriteFile
WriteStringToFile
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 1 for success, 0 for failure.
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