Atom Lianja Reference Documentation

Atom

Represents an Atom document. The Atom API allows one to download, create and modify Atom documents.

Object Creation

loObject = createobject("CkAtom")

Properties

AbortCurrent As Boolean (read-only)

Introduced in version 9.5.0.58

When set to .T., causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to .F. when the next method is called. When the abort occurs, this property is reset to .F.. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

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.

Concept of LastErrorText

LastErrorText Standard 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.

NumEntries As Numeric (read-only)

Number of entries in the Atom document.

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 "9.5.0.63"

Methods

AddElement(tag As Character, value As Character) As Numeric

Adds a new element to the Atom document. The tag is a string such as "title", "subtitle", "summary", etc. Returns the index of the element added, or -1 for failure.

AddElementDateStr(tag As Character, dateTimeStr As Character) As Numeric

Adds a new date-formatted element to the Atom document. The tag is a string such as "created", "modified", "issued", etc. The dateTimeStr should be an RFC822 formatted date/time string such as "Tue, 25 Sep 2012 12:25:32 -0500". Returns the index of the element added, or -1 for failure.

AddElementDt(tag As Character, dateTime As CkDateTime) As Numeric

Adds a new date-formatted element to the Atom document. The tag is a string such as "created", "modified", "issued", etc. Returns the index of the element added, or -1 for failure.

AddElementHtml(tag As Character, htmlStr As Character) As Numeric

Adds a new HTML formatted element to the Atom document. Returns the index of the element added, or -1 for failure.

AddElementXHtml(tag As Character, xmlStr As Character) As Numeric

Adds a new XHTML formatted element to the Atom document. Returns the index of the element added, or -1 for failure.

AddElementXml(tag As Character, xmlStr As Character) As Numeric

Adds a new XML formatted element to the Atom document. Returns the index of the element added, or -1 for failure.

AddEntry(xmlStr As Character)

Adds an "entry" Atom XML document to the caller's Atom document.

AddLink(rel As Character, href As Character, title As Character, typ As Character)

Adds a link to the Atom document.

AddPerson(tag As Character, name As Character, uri As Character, email As Character)

Adds a person to the Atom document. The tag should be a string such as "author", "contributor", etc. If a piece of information is not known, an empty string or NULL value may be passed.

DeleteElement(tag As Character, index As Numeric)

Removes the Nth occurrence of a given element from the Atom document. Indexing begins at 0. For example, to remove the 2nd category, set tag = "category" and index = 1.

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

Remove an attribute from an element.The index should be 0 unless there are multiple elements having the same tag, in which case it selects the Nth occurrence based on the index ( 0 = first occurrence ).

DeletePerson(tag As Character, index As Numeric)

Deletes a person from the Atom document. The tag is a string such as "author". The index should be 0 unless there are multiple elements having the same tag, in which case it selects the Nth occurrence based on the index. For example, DeletePerson("author",2) deletes the 3rd author.

DownloadAtom(url As Character) As Boolean

Download an Atom feed from the Internet and load it into the Atom object.

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

DownloadAtomAsync(url As Character) As CkTask

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

Returns .F. on failure

How to Run an Asynchronous Task

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

Returns the content of the Nth element having a specified tag.

Returns .F. on failure

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

Returns the value of an element's attribute. The element is selected by the tag name and the index (the Nth element having a specific tag) and the attribute is selected by name.

Returns .F. on failure

GetElementCount(tag As Character) As Numeric

The number of elements having a specific tag.

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

Returns an element's value as a date/time in an RFC822 formatted string, such as such as "Tue, 25 Sep 2012 12:25:32 -0500".

Returns .F. on failure

GetElementDt(tag As Character, index As Numeric) As CkDateTime

Returns an element's value as a date/time object.

Returns .F. on failure

GetEntry(index As Numeric) As CkAtom

Returns the Nth entry as an Atom object. (Indexing begins at 0)

Returns .F. on failure

GetLinkHref(relName As Character) As Character

Returns the href attribute of the link having a specified "rel" attribute (such as "service.feed", "alternate", etc.).

Returns .F. on failure

GetPersonInfo(tag As Character, index As Numeric, tag2 As Character) As Character

Returns a piece of information about a person. To get the 2nd author's name, call GetPersonInfo("author",1,"name").

Returns .F. on failure

GetTopAttr(attrName As Character) As Character

Returns the value of an attribute on the top-level XML node. The tag of a top-level Atom XML node is typically "feed" or "entry", and it might have attributes such as "xmlns" and "xml:lang".

Returns .F. on failure

HasElement(tag As Character) As Boolean

True (1) if the element exists in the Atom document. Otherwise 0.

LoadXml(xmlStr As Character) As Boolean

Loads the Atom document from an XML string.

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

NewEntry()

Initializes the Atom document to be a new "entry".

NewFeed()

Initializes the Atom document to be a new "feed".

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.

SetElementAttr(tag As Character, index As Numeric, attrName As Character, attrValue As Character)

Adds or replaces an attribute on an element.

SetTopAttr(attrName As Character, value As Character)

Adds or replaces an attribute on the top-level XML node of the Atom document.

ToXmlString() As Character

Serializes the Atom document to an XML string.

Returns .F. on failure

UpdateElement(tag As Character, index As Numeric, value As Character)

Replaces the content of an element.

UpdateElementDateStr(tag As Character, index As Numeric, dateTimeStr As Character)

Replaces the content of a date-formatted element. The index should be an RFC822 formatted date/time string.

UpdateElementDt(tag As Character, index As Numeric, dateTime As CkDateTime)

Replaces the content of a date-formatted element.

UpdateElementHtml(tag As Character, index As Numeric, htmlStr As Character)

Replaces the content of an HTML element.

UpdateElementXHtml(tag As Character, index As Numeric, xmlStr As Character)

Replaces the content of an XHTML element.

UpdateElementXml(tag As Character, index As Numeric, xmlStr As Character)

Replaces the content of an XML element.

UpdatePerson(tag As Character, index As Numeric, name As Character, uri As Character, email As Character)

Replaces the content of a person. To update the 3rd author, call UpdatePerson("author",2,"new name","new URL","new email"). If a piece of information is not known, pass an empty string or a NULL.