Rss Unicode C Reference Documentation

Rss

Deprecated To be removed in a future version, and should no longer be used.
Current Version: 10.1.2

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.

Create/Dispose

HCkRssW instance = CkRssW_Create();
// ...
CkRssW_Dispose(instance);
HCkRssW CkRssW_Create(void);

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

void CkRssW_Dispose(HCkRssW handle);

Objects created by calling CkRssW_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 CkRssW_Dispose.

Callback Functions

Callback Functions introduced in Chilkat v9.5.0.56
void CkRssW_setAbortCheck(HCkRssW 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 CkRssW_setPercentDone(HCkRssW 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 CkRssW_setProgressInfo(HCkRssW 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 CkRssW_setTaskCompleted(HCkRssW cHandle, void (*fnTaskCompleted)(HCkTaskW 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

DebugLogFilePath
void CkRssW_getDebugLogFilePath(HCkRssW cHandle, HCkString retval);
void CkRssW_putDebugLogFilePath(HCkRssW cHandle, const wchar_t *newVal);
const wchar_t *CkRssW_debugLogFilePath(HCkRssW cHandle);

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

  • A timeout property set to 0, indicating an infinite timeout.
  • A hang occurring within an event callback in the application code.
  • An internal bug in the Chilkat code causing the hang.

More Information and Examples
top
LastErrorHtml
void CkRssW_getLastErrorHtml(HCkRssW cHandle, HCkString retval);
const wchar_t *CkRssW_lastErrorHtml(HCkRssW cHandle);

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

top
LastErrorText
void CkRssW_getLastErrorText(HCkRssW cHandle, HCkString retval);
const wchar_t *CkRssW_lastErrorText(HCkRssW cHandle);

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

top
LastErrorXml
void CkRssW_getLastErrorXml(HCkRssW cHandle, HCkString retval);
const wchar_t *CkRssW_lastErrorXml(HCkRssW cHandle);

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

top
LastMethodSuccess
BOOL CkRssW_getLastMethodSuccess(HCkRssW cHandle);
void CkRssW_putLastMethodSuccess(HCkRssW cHandle, BOOL newVal);

Indicates the success or failure of the most recent method call: TRUE means success, FALSE means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages.

top
NumChannels
int CkRssW_getNumChannels(HCkRssW cHandle);

The number of channels in the RSS document.

top
NumItems
int CkRssW_getNumItems(HCkRssW cHandle);

The number of items in the channel.

top
VerboseLogging
BOOL CkRssW_getVerboseLogging(HCkRssW cHandle);
void CkRssW_putVerboseLogging(HCkRssW 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.

top
Version
void CkRssW_getVersion(HCkRssW cHandle, HCkString retval);
const wchar_t *CkRssW_version(HCkRssW cHandle);

Version of the component/library, such as "10.1.0"

More Information and Examples
top

Methods

AddNewChannel
HCkRssW CkRssW_AddNewChannel(HCkRssW cHandle);

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

Returns NULL on failure

top
AddNewImage
HCkRssW CkRssW_AddNewImage(HCkRssW cHandle);

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

Returns NULL on failure

top
AddNewItem
HCkRssW CkRssW_AddNewItem(HCkRssW cHandle);

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

Returns NULL on failure

top
DownloadRss
BOOL CkRssW_DownloadRss(HCkRssW cHandle, const wchar_t *url);

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

Returns TRUE for success, FALSE for failure.

More Information and Examples
top
DownloadRssAsync (1)
HCkTaskW CkRssW_DownloadRssAsync(HCkRssW cHandle, const wchar_t *url);

Creates an asynchronous task to call the DownloadRss method with the arguments provided.

Returns NULL on failure

top
GetAttr
BOOL CkRssW_GetAttr(HCkRssW cHandle, const wchar_t *tag, const wchar_t *attrName, const wchar_t *outStr);
const wchar_t *CkRssW_getAttr(HCkRssW cHandle, const wchar_t *tag, const wchar_t *attrName);

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 TRUE for success, FALSE for failure.

top
GetChannel
HCkRssW CkRssW_GetChannel(HCkRssW cHandle, int index);

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.

Returns NULL on failure

top
GetCount
int CkRssW_GetCount(HCkRssW cHandle, const wchar_t *tag);

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

top
GetDateStr
BOOL CkRssW_GetDateStr(HCkRssW cHandle, const wchar_t *tag, const wchar_t *outStr);
const wchar_t *CkRssW_getDateStr(HCkRssW cHandle, const wchar_t *tag);

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

Returns TRUE for success, FALSE for failure.

top
GetImage
HCkRssW CkRssW_GetImage(HCkRssW cHandle);

Return the image associated with the channel.

Returns NULL on failure

top
GetInt
int CkRssW_GetInt(HCkRssW cHandle, const wchar_t *tag);

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

top
GetItem
HCkRssW CkRssW_GetItem(HCkRssW cHandle, int index);

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

Returns NULL on failure

top
GetString
BOOL CkRssW_GetString(HCkRssW cHandle, const wchar_t *tag, const wchar_t *outStr);
const wchar_t *CkRssW_getString(HCkRssW cHandle, const wchar_t *tag);

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

Returns TRUE for success, FALSE for failure.

top
LoadRssFile
BOOL CkRssW_LoadRssFile(HCkRssW cHandle, const wchar_t *filePath);

Load an RSS document from a file.

Returns TRUE for success, FALSE for failure.

top
LoadRssString
BOOL CkRssW_LoadRssString(HCkRssW cHandle, const wchar_t *rssString);

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

Returns TRUE for success, FALSE for failure.

top
LoadTaskCaller
BOOL CkRssW_LoadTaskCaller(HCkRssW cHandle, HCkTaskW task);
Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns TRUE for success, FALSE for failure.

top
MGetAttr
BOOL CkRssW_MGetAttr(HCkRssW cHandle, const wchar_t *tag, int index, const wchar_t *attrName, const wchar_t *outStr);
const wchar_t *CkRssW_mGetAttr(HCkRssW cHandle, const wchar_t *tag, int index, const wchar_t *attrName);

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 TRUE for success, FALSE for failure.

top
MGetString
BOOL CkRssW_MGetString(HCkRssW cHandle, const wchar_t *tag, int index, const wchar_t *outStr);
const wchar_t *CkRssW_mGetString(HCkRssW cHandle, const wchar_t *tag, int index);

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

Returns TRUE for success, FALSE for failure.

top
MSetAttr
BOOL CkRssW_MSetAttr(HCkRssW cHandle, const wchar_t *tag, int idx, const wchar_t *attrName, const wchar_t *value);

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

Returns TRUE for success, FALSE for failure.

top
MSetString
BOOL CkRssW_MSetString(HCkRssW cHandle, const wchar_t *tag, int idx, const wchar_t *value);

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

Returns TRUE for success, FALSE for failure.

top
NewRss
void CkRssW_NewRss(HCkRssW cHandle);

Clears the RSS document.

top
Remove
void CkRssW_Remove(HCkRssW cHandle, const wchar_t *tag);

Removes a sub-element from the RSS document.

top
SetAttr
void CkRssW_SetAttr(HCkRssW cHandle, const wchar_t *tag, const wchar_t *attrName, const wchar_t *value);

Sets the value of a sub-element attribute.

top
SetDateNow
void CkRssW_SetDateNow(HCkRssW cHandle, const wchar_t *tag);

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

top
SetDateStr
void CkRssW_SetDateStr(HCkRssW cHandle, const wchar_t *tag, const wchar_t *dateTimeStr);

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

top
SetInt
void CkRssW_SetInt(HCkRssW cHandle, const wchar_t *tag, int value);

Sets the value of an integer sub-element.

top
SetString
void CkRssW_SetString(HCkRssW cHandle, const wchar_t *tag, const wchar_t *value);

Sets the value of a sub-element.

top
ToXmlString
BOOL CkRssW_ToXmlString(HCkRssW cHandle, const wchar_t *outStr);
const wchar_t *CkRssW_toXmlString(HCkRssW cHandle);

Returns the RSS document as an XML string.

Returns TRUE for success, FALSE for failure.

top