Atom C Reference Documentation

Atom

Current Version: 9.5.0.73

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

Create/Dispose

HCkAtom instance = CkAtom_Create();
// ...
CkAtom_Dispose(instance);
HCkAtom CkAtom_Create(void);

Creates an instance of the HCkAtom object and returns a handle ("void *" pointer). The handle is passed in the 1st argument for the functions listed on this page.

void CkAtom_Dispose(HCkAtom handle);

Objects created by calling CkAtom_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function. Also, any handle returned by a Chilkat "C" function must also be freed by the application by calling the appropriate Dispose method, such as CkAtom_Dispose.

Callback Functions

Callback Functions introduced in Chilkat v9.5.0.56
void CkAtom_setAbortCheck(HCkAtom cHandle, BOOL (*fnAbortCheck)(void));

Provides the opportunity for a method call to be aborted. If TRUE is returned, the operation in progress is aborted. Return FALSE to allow the current method call to continue. This callback function is called periodically based on the value of the HeartbeatMs property. (If HeartbeatMs is 0, then no callbacks are made.) As an example, to make 5 AbortCheck callbacks per second, set the HeartbeatMs property equal to 200.

void CkAtom_setPercentDone(HCkAtom cHandle, BOOL (*fnPercentDone)(int pctDone));

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 callback is only called 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 methods 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).

This callback counts as an AbortCheck callback, and takes the place of the AbortCheck event when it fires.

The return value indicates whether the method call should be aborted, or whether it should proceed. Return TRUE to abort, and FALSE to proceed.

void CkAtom_setProgressInfo(HCkAtom cHandle, void (*fnProgressInfo)(const char *name, const char *value));

This is a general callback that provides name/value information about what is happening at certain points during a method call. To see the information provided in ProgressInfo callbacks, if any, write code to handle this event and log the name/value pairs. Most are self-explanatory.

void CkAtom_setTaskCompleted(HCkAtom cHandle, void (*fnTaskCompleted)(HCkTask hTask));

Called in the background thread when an asynchronous task completes. (Note: When an async method is running, all callbacks are in the background thread.)

Properties

AbortCurrent
BOOL CkAtom_getAbortCurrent(HCkAtom cHandle);
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.)

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DebugLogFilePath
void CkAtom_getDebugLogFilePath(HCkAtom cHandle, HCkString retval);
void CkAtom_putDebugLogFilePath(HCkAtom cHandle, const char *newVal);
const char *CkAtom_debugLogFilePath(HCkAtom cHandle);

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.

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LastErrorHtml
void CkAtom_getLastErrorHtml(HCkAtom cHandle, HCkString retval);
const char *CkAtom_lastErrorHtml(HCkAtom cHandle);

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.

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LastErrorText
void CkAtom_getLastErrorText(HCkAtom cHandle, HCkString retval);
const char *CkAtom_lastErrorText(HCkAtom cHandle);

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.

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LastErrorXml
void CkAtom_getLastErrorXml(HCkAtom cHandle, HCkString retval);
const char *CkAtom_lastErrorXml(HCkAtom cHandle);

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.

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LastMethodSuccess
BOOL CkAtom_getLastMethodSuccess(HCkAtom cHandle);
void CkAtom_putLastMethodSuccess(HCkAtom cHandle, BOOL newVal);
Introduced in version 9.5.0.52

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.

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NumEntries
int CkAtom_getNumEntries(HCkAtom cHandle);

Number of entries in the Atom document.

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Utf8
BOOL CkAtom_getUtf8(HCkAtom cHandle);
void CkAtom_putUtf8(HCkAtom cHandle, 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.

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VerboseLogging
BOOL CkAtom_getVerboseLogging(HCkAtom cHandle);
void CkAtom_putVerboseLogging(HCkAtom cHandle, 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.

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Version
void CkAtom_getVersion(HCkAtom cHandle, HCkString retval);
const char *CkAtom_version(HCkAtom cHandle);

Version of the component/library, such as "9.5.0.63"

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Methods

AddElement
int CkAtom_AddElement(HCkAtom cHandle, 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.

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AddElementDate
int CkAtom_AddElementDate(HCkAtom cHandle, const char *tag, SYSTEMTIME * dateTime);
This method is deprecated. It will be removed in a future version.

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.

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AddElementDateStr
int CkAtom_AddElementDateStr(HCkAtom cHandle, 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.

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AddElementDt
int CkAtom_AddElementDt(HCkAtom cHandle, const char *tag, HCkDateTime 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.

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AddElementHtml
int CkAtom_AddElementHtml(HCkAtom cHandle, 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.

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AddElementXHtml
int CkAtom_AddElementXHtml(HCkAtom cHandle, 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.

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AddElementXml
int CkAtom_AddElementXml(HCkAtom cHandle, 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.

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AddEntry
void CkAtom_AddEntry(HCkAtom cHandle, const char *xmlStr);

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

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

Adds a link to the Atom document.

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AddPerson
void CkAtom_AddPerson(HCkAtom cHandle, 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.

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DeleteElement
void CkAtom_DeleteElement(HCkAtom cHandle, 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.

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DeleteElementAttr
void CkAtom_DeleteElementAttr(HCkAtom cHandle, 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 ).

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DeletePerson
void CkAtom_DeletePerson(HCkAtom cHandle, 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.

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DownloadAtom
BOOL CkAtom_DownloadAtom(HCkAtom cHandle, const char *url);

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

Returns TRUE for success, FALSE for failure.

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DownloadAtomAsync (1)
HCkTask CkAtom_DownloadAtomAsync(HCkAtom cHandle, 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.)

Returns NULL on failure

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GetElement
BOOL CkAtom_GetElement(HCkAtom cHandle, const char *tag, int index, HCkString outStr);
const char *CkAtom_getElement(HCkAtom cHandle, const char *tag, int index);

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

Returns TRUE for success, FALSE for failure.

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GetElementAttr
BOOL CkAtom_GetElementAttr(HCkAtom cHandle, const char *tag, int index, const char *attrName, HCkString outStr);
const char *CkAtom_getElementAttr(HCkAtom cHandle, 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.

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GetElementCount
int CkAtom_GetElementCount(HCkAtom cHandle, const char *tag);

The number of elements having a specific tag.

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GetElementDate
BOOL CkAtom_GetElementDate(HCkAtom cHandle, const char *tag, int index, SYSTEMTIME *outSysTime);
This method is deprecated. It will be removed in a future version.

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

Returns TRUE for success, FALSE for failure.

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GetElementDateStr
BOOL CkAtom_GetElementDateStr(HCkAtom cHandle, const char *tag, int index, HCkString outStr);
const char *CkAtom_getElementDateStr(HCkAtom cHandle, 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.

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GetElementDt
HCkDateTime CkAtom_GetElementDt(HCkAtom cHandle, const char *tag, int index);

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

Returns NULL on failure

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GetEntry
HCkAtom CkAtom_GetEntry(HCkAtom cHandle, int index);

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

Returns NULL on failure

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GetLinkHref
BOOL CkAtom_GetLinkHref(HCkAtom cHandle, const char *relName, HCkString outStr);
const char *CkAtom_getLinkHref(HCkAtom cHandle, 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.

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GetPersonInfo
BOOL CkAtom_GetPersonInfo(HCkAtom cHandle, const char *tag, int index, const char *tag2, HCkString outStr);
const char *CkAtom_getPersonInfo(HCkAtom cHandle, 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.

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GetTopAttr
BOOL CkAtom_GetTopAttr(HCkAtom cHandle, const char *attrName, HCkString outStr);
const char *CkAtom_getTopAttr(HCkAtom cHandle, 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.

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HasElement
BOOL CkAtom_HasElement(HCkAtom cHandle, const char *tag);

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

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LoadXml
BOOL CkAtom_LoadXml(HCkAtom cHandle, const char *xmlStr);

Loads the Atom document from an XML string.

Returns TRUE for success, FALSE for failure.

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NewEntry
void CkAtom_NewEntry(HCkAtom cHandle);

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

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NewFeed
void CkAtom_NewFeed(HCkAtom cHandle);

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

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SaveLastError
BOOL CkAtom_SaveLastError(HCkAtom cHandle, const char *path);

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

Returns TRUE for success, FALSE for failure.

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

Adds or replaces an attribute on an element.

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SetTopAttr
void CkAtom_SetTopAttr(HCkAtom cHandle, const char *attrName, const char *value);

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

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ToXmlString
BOOL CkAtom_ToXmlString(HCkAtom cHandle, HCkString outStr);
const char *CkAtom_toXmlString(HCkAtom cHandle);

Serializes the Atom document to an XML string.

Returns TRUE for success, FALSE for failure.

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

Replaces the content of an element.

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UpdateElementDate
void CkAtom_UpdateElementDate(HCkAtom cHandle, const char *tag, int index, SYSTEMTIME * dateTime);
This method is deprecated. It will be removed in a future version.

Replaces the content of a date-formatted element.

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UpdateElementDateStr
void CkAtom_UpdateElementDateStr(HCkAtom cHandle, 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.

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UpdateElementDt
void CkAtom_UpdateElementDt(HCkAtom cHandle, const char *tag, int index, HCkDateTime dateTime);

Replaces the content of a date-formatted element.

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

Replaces the content of an HTML element.

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

Replaces the content of an XHTML element.

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

Replaces the content of an XML element.

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UpdatePerson
void CkAtom_UpdatePerson(HCkAtom cHandle, 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.

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