Rss Lianja Reference Documentation

Rss

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

loObject = createobject("CkRss")

Properties

DebugLogFilePath As Character

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:

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

LastErrorHtml As Character (read-only)

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 As Character (read-only)

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 As Character (read-only)

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 As Boolean

Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of .T. indicates success, a value of .F. 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 = .T. and failure = .F..
  • 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 .T.. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

NumChannels As Numeric (read-only)

The number of channels in the RSS document.

NumItems As Numeric (read-only)

The number of items in the channel.

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.

Version As Character (read-only)

Version of the component/library, such as "9.4.1.42"

Methods

AddNewChannel() As CkRss

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

AddNewImage() As CkRss

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

AddNewItem() As CkRss

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

DownloadRss(url As Character) As Boolean

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

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

Example: Read RSS Feed

DownloadRssAsync(url As Character) As CkTask

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

How to Run an Asynchronous Task

GetAttr(tag As Character, attrName As Character) As Character

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

GetChannel(index As Numeric) As CkRss

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.

GetCount(tag As Character) As Numeric

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

GetDateStr(tag As Character) As Character

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

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

GetImage() As CkRss

Return the image associated with the channel.

GetInt(tag As Character) As Numeric

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

GetItem(index As Numeric) As CkRss

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

GetString(tag As Character) As Character

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

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

LoadRssFile(filePath As Character) As Boolean

Load an RSS document from a file.

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

LoadRssString(rssString As Character) As Boolean

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

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

MGetAttr(tag As Character, index As Numeric, attrName As Character) As Character

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

MGetString(tag As Character, index As Numeric) As Character

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

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

MSetAttr(tag As Character, idx As Numeric, attrName As Character, value As Character) As Boolean

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

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

MSetString(tag As Character, idx As Numeric, value As Character) As Boolean

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

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

NewRss()

Clears the RSS document.

Remove(tag As Character)

Removes a sub-element from the RSS document.

SaveLastError(path As Character) As Boolean

Saves the last-error information (the contents of LastErrorXml) to an XML formatted file.

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

SetAttr(tag As Character, attrName As Character, value As Character)

Sets the value of a sub-element attribute.

SetDateNow(tag As Character)

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

SetDateStr(tag As Character, dateTimeStr As Character)

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

SetInt(tag As Character, value As Numeric)

Sets the value of an integer sub-element.

SetString(tag As Character, value As Character)

Sets the value of a sub-element.

ToXmlString() As Character

Returns the RSS document as an XML string.

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