Rss DataFlex Reference Documentation

Rss

Current Version: 9.5.0.98

Represents an RSS document or sub-part of a document such as a channel, image, or item. The RSS API allows one to download, create and modify RSS documents.

Object Creation

// (Dataflex programs use the 32-bit Chilkat ActiveX)
Handle hoRss
Get Create(RefClass(cComChilkatRss)) to hoRss

Properties

DebugLogFilePath

Function ComDebugLogFilePath Returns String
Procedure Set ComDebugLogFilePath String value

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.

LastBinaryResult

Function ComLastBinaryResult Returns Variant

The binary data returned by the last (binary data returning) method called. Only available if Chilkat.Global.KeepBinaryResult is set to True. 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).

LastErrorHtml

Function ComLastErrorHtml Returns String

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

Function ComLastErrorText Returns String

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

Function ComLastErrorXml Returns String

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

Function ComLastMethodSuccess Returns Boolean
Procedure Set ComLastMethodSuccess Boolean value

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.

LastStringResult

Function ComLastStringResult Returns String

The string return value of the last (string returning) method called. Only available if Chilkat.Global.KeepStringResult is set to True. 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).

More Information and Examples

Long Strings Returned by ActiveX Methods in SQL Server

LastStringResultLen

Function ComLastStringResultLen Returns Integer

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

NumChannels

Function ComNumChannels Returns Integer

The number of channels in the RSS document.

NumItems

Function ComNumItems Returns Integer

The number of items in the channel.

VerboseLogging

Function ComVerboseLogging Returns Boolean
Procedure Set ComVerboseLogging Boolean value

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

Function ComVersion Returns String

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

More Information and Examples

How to get the Chilkat version at runtime.

Methods

AddNewChannel

Function ComAddNewChannel Returns cComChilkatRss

Adds a new channel to the RSS document. Returns the Rss object representing the Channel which can then be edited.

Returns null on failure

AddNewImage

Function ComAddNewImage Returns cComChilkatRss

Adds a new image to the RSS document. Returns the Rss object representing the image, which can then be edited.

Returns null on failure

AddNewItem

Function ComAddNewItem Returns cComChilkatRss

Adds a new Item to an Rss channel. Returns the Rss object representing the item which can then be edited.

Returns null on failure

DownloadRss

Function ComDownloadRss String url Returns Boolean

Downloads an RSS document from the Internet and populates the Rss object with the contents.

Returns True for success, False for failure.

More Information and Examples

Example: Read RSS Feed

DownloadRssAsync ⁽¹⁾

Function ComDownloadRssAsync String url Returns cComChilkatTask

Creates an asynchronous task to call the DownloadRss method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns null on failure

GetAttr

Function ComGetAttr String tag String attrName Returns String

Returns the value of a sub-element attribute. For example, to get the value of the "isPermaLink" attribute of the "guid" sub-element, call item.GetAttr("guid","isPermaLink").

Returns null on failure

GetChannel

Function ComGetChannel Integer index Returns cComChilkatRss

Returns the Nth channel of an RSS document. Usually there is only 1 channel per document, so the index argument should be set to 0.

Returns null on failure

GetCount

Function ComGetCount String tag Returns Integer

Return the number of sub-elements with a specific tag.

GetDateStr

Function ComGetDateStr String tag Returns String

The same as GetDate, except the date/time is returned in RFC822 string format.

Returns null on failure

GetImage

Function ComGetImage Returns cComChilkatRss

Return the image associated with the channel.

Returns null on failure

GetInt

Function ComGetInt String tag Returns Integer

Return the value of a numeric sub-element as an integer.

GetItem

Function ComGetItem Integer index Returns cComChilkatRss

Return the Nth item of a channel as an RSS object.

Returns null on failure

GetString

Function ComGetString String tag Returns String

Return the value of an sub-element as a string.

Returns null on failure

LoadRssFile

Function ComLoadRssFile String filePath Returns Boolean

Load an RSS document from a file.

Returns True for success, False for failure.

LoadRssString

Function ComLoadRssString String rssString Returns Boolean

Loads an RSS feed document from an in-memory string.

Returns True for success, False for failure.

LoadTaskCaller

Function ComLoadTaskCaller cComChilkatTask task Returns Boolean

Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns True for success, False for failure.

MGetAttr

Function ComMGetAttr String tag Integer index String attrName Returns String

Get an attribute value for the Nth sub-element having a specific tag. As an example, an RSS item may have several "category" sub-elements. To get the value of the "domain" attribute for the 3rd category, call MGetAttr("category",2,"domain").

Returns null on failure

MGetString

Function ComMGetString String tag Integer index Returns String

Get the value of the Nth occurrence of a sub-element. Indexing begins at 0.

Returns null on failure

MSetAttr

Function ComMSetAttr String tag Integer idx String attrName String value Returns Boolean

Set an attribute on the Nth occurrence of a sub-element.

Returns True for success, False for failure.

MSetString

Function ComMSetString String tag Integer idx String value Returns Boolean

Set the value of the Nth occurrence of a sub-element. Indexing begins at 0.

Returns True for success, False for failure.

NewRss

Procedure ComNewRss

Clears the RSS document.

Remove

Procedure ComRemove String tag

Removes a sub-element from the RSS document.

SetAttr

Procedure ComSetAttr String tag String attrName String value

Sets the value of a sub-element attribute.

SetDateNow

Procedure ComSetDateNow String tag

Sets the value of a date/time sub-element to the current system date/time.

SetDateStr

Procedure ComSetDateStr String tag String dateTimeStr

The same as SetDate, except the date/time is passed as an RFC822 string.

SetInt

Procedure ComSetInt String tag Integer value

Sets the value of an integer sub-element.

SetString

Procedure ComSetString String tag String value

Sets the value of a sub-element.

ToXmlString

Function ComToXmlString Returns String

Returns the RSS document as an XML string.

Returns null on failure