Atom Unicode C Reference Documentation

Atom

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

Create/Dispose

HCkAtomW CkAtomW_Create(void);

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

void CkAtomW_Dispose(HCkAtomW handle);

Objects created by calling CkAtomW_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 CkAtomW_Dispose.

Callback Functions

Callback Functions are Introduced in Chilkat v9.5.0.56

void CkAtomW_setAbortCheck(HCkHttp cHandle, BOOL (*fnAbortCheck)());

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.

C Example using Callback Functions

void CkAtomW_setPercentDone(HCkHttp 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 CkAtomW_setProgressInfo(HCkHttp cHandle, void (*fnProgressInfo)(const wchar_t *name, const wchar_t *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 CkAtomW_setTaskCompleted(HCkHttp 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

BOOL CkAtomW_getAbortCurrent(HCkAtomW 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.)

void CkAtomW_getDebugLogFilePath(HCkAtomW cHandle, HCkString retval);

void CkAtomW_putDebugLogFilePath(HCkAtomW cHandle, const wchar_t *newVal);

const wchar_t *CkAtomW_debugLogFilePath(HCkAtomW 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.

void CkAtomW_getLastErrorHtml(HCkAtomW cHandle, HCkString retval);

const wchar_t *CkAtomW_lastErrorHtml(HCkAtomW 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.

void CkAtomW_getLastErrorText(HCkAtomW cHandle, HCkString retval);

const wchar_t *CkAtomW_lastErrorText(HCkAtomW 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.

Concept of LastErrorText

LastErrorText Standard Information

void CkAtomW_getLastErrorXml(HCkAtomW cHandle, HCkString retval);

const wchar_t *CkAtomW_lastErrorXml(HCkAtomW 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.

BOOL CkAtomW_getLastMethodSuccess(HCkAtomW cHandle);

void CkAtomW_putLastMethodSuccess(HCkAtomW 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.

int CkAtomW_getNumEntries(HCkAtomW cHandle);

Number of entries in the Atom document.

BOOL CkAtomW_getVerboseLogging(HCkAtomW cHandle);

void CkAtomW_putVerboseLogging(HCkAtomW 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.

void CkAtomW_getVersion(HCkAtomW cHandle, HCkString retval);

const wchar_t *CkAtomW_version(HCkAtomW cHandle);

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

Methods

int CkAtomW_AddElement(HCkAtomW cHandle, const wchar_t *tag, const wchar_t *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.

int CkAtomW_AddElementDate(HCkAtomW cHandle, const wchar_t *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.

int CkAtomW_AddElementDateStr(HCkAtomW cHandle, const wchar_t *tag, const wchar_t *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.

int CkAtomW_AddElementDt(HCkAtomW cHandle, const wchar_t *tag, HCkDateTimeW 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.

int CkAtomW_AddElementHtml(HCkAtomW cHandle, const wchar_t *tag, const wchar_t *htmlStr);

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

int CkAtomW_AddElementXHtml(HCkAtomW cHandle, const wchar_t *tag, const wchar_t *xmlStr);

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

int CkAtomW_AddElementXml(HCkAtomW cHandle, const wchar_t *tag, const wchar_t *xmlStr);

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

void CkAtomW_AddEntry(HCkAtomW cHandle, const wchar_t *xmlStr);

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

void CkAtomW_AddLink(HCkAtomW cHandle, const wchar_t *rel, const wchar_t *href, const wchar_t *title, const wchar_t *typ);

Adds a link to the Atom document.

void CkAtomW_AddPerson(HCkAtomW cHandle, const wchar_t *tag, const wchar_t *name, const wchar_t *uri, const wchar_t *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.

void CkAtomW_DeleteElement(HCkAtomW cHandle, const wchar_t *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.

void CkAtomW_DeleteElementAttr(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *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 ).

void CkAtomW_DeletePerson(HCkAtomW cHandle, const wchar_t *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.

BOOL CkAtomW_DownloadAtom(HCkAtomW cHandle, const wchar_t *url);

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

Returns TRUE for success, FALSE for failure.

HCkTaskW CkAtomW_DownloadAtomAsync(HCkAtomW cHandle, const wchar_t *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

How to Run an Asynchronous Task

BOOL CkAtomW_GetElement(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *outStr);

const wchar_t *CkAtomW_getElement(HCkAtomW cHandle, const wchar_t *tag, int index);

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

Returns TRUE for success, FALSE for failure.

BOOL CkAtomW_GetElementAttr(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *attrName, const wchar_t *outStr);

const wchar_t *CkAtomW_getElementAttr(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *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.

int CkAtomW_GetElementCount(HCkAtomW cHandle, const wchar_t *tag);

The number of elements having a specific tag.

BOOL CkAtomW_GetElementDate(HCkAtomW cHandle, const wchar_t *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.

BOOL CkAtomW_GetElementDateStr(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *outStr);

const wchar_t *CkAtomW_getElementDateStr(HCkAtomW cHandle, const wchar_t *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.

HCkDateTimeW CkAtomW_GetElementDt(HCkAtomW cHandle, const wchar_t *tag, int index);

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

Returns NULL on failure

HCkAtomW CkAtomW_GetEntry(HCkAtomW cHandle, int index);

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

Returns NULL on failure

BOOL CkAtomW_GetLinkHref(HCkAtomW cHandle, const wchar_t *relName, const wchar_t *outStr);

const wchar_t *CkAtomW_getLinkHref(HCkAtomW cHandle, const wchar_t *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.

BOOL CkAtomW_GetPersonInfo(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *tag2, const wchar_t *outStr);

const wchar_t *CkAtomW_getPersonInfo(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *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.

BOOL CkAtomW_GetTopAttr(HCkAtomW cHandle, const wchar_t *attrName, const wchar_t *outStr);

const wchar_t *CkAtomW_getTopAttr(HCkAtomW cHandle, const wchar_t *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.

BOOL CkAtomW_HasElement(HCkAtomW cHandle, const wchar_t *tag);

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

BOOL CkAtomW_LoadXml(HCkAtomW cHandle, const wchar_t *xmlStr);

Loads the Atom document from an XML string.

Returns TRUE for success, FALSE for failure.

void CkAtomW_NewEntry(HCkAtomW cHandle);

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

void CkAtomW_NewFeed(HCkAtomW cHandle);

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

BOOL CkAtomW_SaveLastError(HCkAtomW cHandle, const wchar_t *path);

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

Returns TRUE for success, FALSE for failure.

void CkAtomW_SetElementAttr(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *attrName, const wchar_t *attrValue);

Adds or replaces an attribute on an element.

void CkAtomW_SetTopAttr(HCkAtomW cHandle, const wchar_t *attrName, const wchar_t *value);

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

BOOL CkAtomW_ToXmlString(HCkAtomW cHandle, const wchar_t *outStr);

const wchar_t *CkAtomW_toXmlString(HCkAtomW cHandle);

Serializes the Atom document to an XML string.

Returns TRUE for success, FALSE for failure.

void CkAtomW_UpdateElement(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *value);

Replaces the content of an element.

void CkAtomW_UpdateElementDate(HCkAtomW cHandle, const wchar_t *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.

void CkAtomW_UpdateElementDateStr(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *dateTimeStr);

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

void CkAtomW_UpdateElementDt(HCkAtomW cHandle, const wchar_t *tag, int index, HCkDateTimeW dateTime);

Replaces the content of a date-formatted element.

void CkAtomW_UpdateElementHtml(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *htmlStr);

Replaces the content of an HTML element.

void CkAtomW_UpdateElementXHtml(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *xmlStr);

Replaces the content of an XHTML element.

void CkAtomW_UpdateElementXml(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *xmlStr);

Replaces the content of an XML element.

void CkAtomW_UpdatePerson(HCkAtomW cHandle, const wchar_t *tag, int index, const wchar_t *name, const wchar_t *uri, const wchar_t *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.