CkAtom C++ Reference Documentation

CkAtom

Current Version: 10.0.0

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

Object Creation

// Local variable on the stack
CkAtom obj;

// Dynamically allocate/delete
CkAtom *pObj = new CkAtom();
// ...
delete pObj;

Properties

AbortCurrent

bool get_AbortCurrent(void);

Introduced in version 9.5.0.58

When set to true, 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 false when the next method is called. When the abort occurs, this property is reset to false. 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

void get_DebugLogFilePath(CkString &str);
const char *debugLogFilePath(void);
void put_DebugLogFilePath(const char *ansiOrUtf8Str);

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.

LastErrorHtml

void get_LastErrorHtml(CkString &str);
const char *lastErrorHtml(void);

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

void get_LastErrorText(CkString &str);
const char *lastErrorText(void);

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

void get_LastErrorXml(CkString &str);
const char *lastErrorXml(void);

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

bool get_LastMethodSuccess(void);
void put_LastMethodSuccess(bool newVal);

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.

NumEntries

int get_NumEntries(void);

Number of entries in the Atom document.

Utf8

bool get_Utf8(void);
void put_Utf8(bool newVal);

When set to true, all "const char *" arguments are interpreted as utf-8 strings. If set to false (the default), then "const char *" arguments are interpreted as ANSI strings. Also, when set to true, and Chilkat method returning a "const char *" is returning the utf-8 representation. If set to false, all "const char *" return values are ANSI strings.

VerboseLogging

bool get_VerboseLogging(void);
void put_VerboseLogging(bool newVal);

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

void get_Version(CkString &str);
const char *version(void);

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

More Information and Examples

How to get the Chilkat version at runtime.

Methods

AddElement

int AddElement(const char *tag, const char *value);

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

int AddElementDateStr(const char *tag, const char *dateTimeStr);

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

int AddElementDt(const char *tag, CkDateTime &dateTime);

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

int AddElementHtml(const char *tag, const char *htmlStr);

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

AddElementXHtml

int AddElementXHtml(const char *tag, const char *xmlStr);

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

AddElementXml

int AddElementXml(const char *tag, const char *xmlStr);

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

AddEntry

void AddEntry(const char *xmlStr);

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

AddLink

void AddLink(const char *rel, const char *href, const char *title, const char *typ);

Adds a link to the Atom document.

AddPerson

void AddPerson(const char *tag, const char *name, const char *uri, const char *email);

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

void DeleteElement(const char *tag, int index);

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

void DeleteElementAttr(const char *tag, int index, const char *attrName);

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

void DeletePerson(const char *tag, int index);

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

bool DownloadAtom(const char *url);

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

Returns true for success, false for failure.

DownloadAtomAsync ⁽¹⁾

CkTask *DownloadAtomAsync(const char *url);

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

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Note: The application is responsible for deleting (via the C++ delete operator) the object returned by this method.

Returns NULL on failure

GetElement

bool GetElement(const char *tag, int index, CkString &outStr);
const char *getElement(const char *tag, int index);

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

Returns true for success, false for failure.

GetElementAttr

bool GetElementAttr(const char *tag, int index, const char *attrName, CkString &outStr);
const char *getElementAttr(const char *tag, int index, const char *attrName);

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 true for success, false for failure.

GetElementCount

int GetElementCount(const char *tag);

The number of elements having a specific tag.

GetElementDateStr

bool GetElementDateStr(const char *tag, int index, CkString &outStr);
const char *getElementDateStr(const char *tag, int index);

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 true for success, false for failure.

GetElementDt

CkDateTime *GetElementDt(const char *tag, int index);

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

Note: The application is responsible for deleting (via the C++ delete operator) the object returned by this method.

Returns NULL on failure

GetEntry

CkAtom *GetEntry(int index);

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

Note: The application is responsible for deleting (via the C++ delete operator) the object returned by this method.

Returns NULL on failure

GetLinkHref

bool GetLinkHref(const char *relName, CkString &outStr);
const char *getLinkHref(const char *relName);

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

Returns true for success, false for failure.

GetPersonInfo

bool GetPersonInfo(const char *tag, int index, const char *tag2, CkString &outStr);
const char *getPersonInfo(const char *tag, int index, const char *tag2);

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

Returns true for success, false for failure.

GetTopAttr

bool GetTopAttr(const char *attrName, CkString &outStr);
const char *getTopAttr(const char *attrName);

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 true for success, false for failure.

HasElement

bool HasElement(const char *tag);

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

LoadTaskCaller

bool LoadTaskCaller(CkTask &task);

Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns true for success, false for failure.

LoadXml

bool LoadXml(const char *xmlStr);

Loads the Atom document from an XML string.

Returns true for success, false for failure.

NewEntry

void NewEntry(void);

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

NewFeed

void NewFeed(void);

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

SetElementAttr

void SetElementAttr(const char *tag, int index, const char *attrName, const char *attrValue);

Adds or replaces an attribute on an element.

SetTopAttr

void SetTopAttr(const char *attrName, const char *value);

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

ToXmlString

bool ToXmlString(CkString &outStr);
const char *toXmlString(void);

Serializes the Atom document to an XML string.

Returns true for success, false for failure.

UpdateElement

void UpdateElement(const char *tag, int index, const char *value);

Replaces the content of an element.

UpdateElementDateStr

void UpdateElementDateStr(const char *tag, int index, const char *dateTimeStr);

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

UpdateElementDt

void UpdateElementDt(const char *tag, int index, CkDateTime &dateTime);

Replaces the content of a date-formatted element.

UpdateElementHtml

void UpdateElementHtml(const char *tag, int index, const char *htmlStr);

Replaces the content of an HTML element.

UpdateElementXHtml

void UpdateElementXHtml(const char *tag, int index, const char *xmlStr);

Replaces the content of an XHTML element.

UpdateElementXml

void UpdateElementXml(const char *tag, int index, const char *xmlStr);

Replaces the content of an XML element.

UpdatePerson

void UpdatePerson(const char *tag, int index, const char *name, const char *uri, const char *email);

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.

Events

To implement an event callback, your application would define and implement a class that inherits from CkBaseProgress. Your application can implement methods to override some or all of the default/empty method implementations of the CkBaseProgress base class.

For example:

  CkAtom atom;

  MyAtomProgress callbackObj;

  atom.put_EventCallbackObject(&callbackObj);

MyAtomProgress example:

#include "CkBaseProgress.h"

class MyAtomProgress : public CkBaseProgress {

  public:
    MyAtomProgress();
    virtual ~MyAtomProgress();

    void AbortCheck(bool  *abort);

    void PercentDone(int pctDone, bool  *abort);

    void ProgressInfo(const char *name, const char *value);

    void TaskCompleted(CkTask &task);

};

AbortCheck

void AbortCheck(bool *abort);

Provides the opportunity for a method call to be aborted. The AbortCheck event is fired periodically based on the value of the HeartbeatMs property. If HeartbeatMs is 0, then no AbortCheck events will fire. As an example, to fire 5 AbortCheck events per second, set the HeartbeatMs property equal to 200.

PercentDone

void PercentDone(int pctDone, bool *abort);

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This event is only fired when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For operations (Chilkat method calls) that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

The PercentDone callback counts as an AbortCheck event. For method calls that complete quickly such that PercentDone events fire, it may be that AbortCheck events don't fire because the opportunity to abort is already provided in the PercentDone callback. For time consuming operations, where the amount of time between PercentDone callbacks are long, AbortCheck callbacks may be used to allow for the operation to be aborted in a more responsive manner.

The abort output argument provides a means for aborting the operation. Setting it to true will cause the method to abort and return a failed status (or whatever return value indicates failure).

ProgressInfo

void ProgressInfo(const char *name, const char *value);

A general name/value event that provides information about what is happening during a method call. To find out what information is available, write code to handle this event and log the name/value pairs. Most are self-explanatory.

TaskCompleted

void TaskCompleted(CkTask &task);

Called in the background thread when an asynchronous task completes.

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