Spider Delphi DLL Reference Documentation
Spider
Current Version: 11.1.0
Chilkat Spider web crawler object.
Create/Dispose
var myObject: HCkSpider; begin myObject := CkSpider_Create(); // ... CkSpider_Dispose(myObject); end;
Creates an instance of the HCkSpider object and returns a handle (i.e. a Pointer). The handle is passed in the 1st argument for the functions listed on this page.
Objects created by calling CkSpider_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function.
Properties
AbortCurrent
procedure CkSpider_putAbortCurrent(objHandle: HCkSpider; newPropVal: wordbool); stdcall;
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.)
AvoidHttps
procedure CkSpider_putAvoidHttps(objHandle: HCkSpider; newPropVal: wordbool); stdcall;
If set the 1 (true) the spider will avoid all HTTPS URLs. The default is 0 (false).
topCacheDir
procedure CkSpider_putCacheDir(objHandle: HCkSpider; newPropVal: PWideChar); stdcall;
function CkSpider__cacheDir(objHandle: HCkSpider): PWideChar; stdcall;
Specifies a cache directory to use for spidering. If either of the FetchFromCache or UpdateCache properties are true, this is the location of the cache to be used. Note: the Internet Explorer, Netscape, and FireFox caches are completely separate from the Chilkat Spider cache directory. You should specify a new and empty directory.
See the notes about PWideChar memory ownership and validity.
ChopAtQuery
procedure CkSpider_putChopAtQuery(objHandle: HCkSpider; newPropVal: wordbool); stdcall;
If equal to 1 (true), then the query portion of all URLs are automatically removed when adding to the unspidered list. The default value is 0 (false).
topConnectTimeout
procedure CkSpider_putConnectTimeout(objHandle: HCkSpider; newPropVal: Integer); stdcall;
The maximum number of seconds to wait while connecting to an HTTP server.
topDebugLogFilePath
procedure CkSpider_putDebugLogFilePath(objHandle: HCkSpider; newPropVal: PWideChar); stdcall;
function CkSpider__debugLogFilePath(objHandle: HCkSpider): PWideChar; stdcall;
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.
See the notes about PWideChar memory ownership and validity.
Domain
function CkSpider__domain(objHandle: HCkSpider): PWideChar; stdcall;
The domain name that is being spidered. This is the domain previously set in the Initialize method.
See the notes about PWideChar memory ownership and validity.
topFetchFromCache
procedure CkSpider_putFetchFromCache(objHandle: HCkSpider; newPropVal: wordbool); stdcall;
If equal to 1 (true) then pages are fetched from cache when possible. If 0, the cache is ignored. The default value is 1. Regardless, if no CacheDir is set then the cache is not used.
FinalRedirectUrl
function CkSpider__finalRedirectUrl(objHandle: HCkSpider): PWideChar; stdcall;
If the last URL crawled was redirected (as indicated by the WasRedirected property), this property will contain the final redirect URL.
See the notes about PWideChar memory ownership and validity.
topHeartbeatMs
procedure CkSpider_putHeartbeatMs(objHandle: HCkSpider; newPropVal: Integer); stdcall;
The interval in milliseconds between each AbortCheck
event callback, which enables an application to abort certain method calls before they complete. By default, HeartbeatMs is set to 0
, meaning no AbortCheck event callbacks will trigger.
LastErrorHtml
function CkSpider__lastErrorHtml(objHandle: HCkSpider): PWideChar; stdcall;
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.
See the notes about PWideChar memory ownership and validity.
topLastErrorText
function CkSpider__lastErrorText(objHandle: HCkSpider): PWideChar; stdcall;
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.
See the notes about PWideChar memory ownership and validity.
LastErrorXml
function CkSpider__lastErrorXml(objHandle: HCkSpider): PWideChar; stdcall;
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.
See the notes about PWideChar memory ownership and validity.
topLastFromCache
Equal to 1 if the last page spidered was fetched from the cache. Otherwise equal to 0.
topLastHtml
function CkSpider__lastHtml(objHandle: HCkSpider): PWideChar; stdcall;
The HTML text of the last paged fetched by the spider.
See the notes about PWideChar memory ownership and validity.
topLastHtmlDescription
function CkSpider__lastHtmlDescription(objHandle: HCkSpider): PWideChar; stdcall;
The HTML META description from the last page fetched by the spider.
See the notes about PWideChar memory ownership and validity.
LastHtmlKeywords
function CkSpider__lastHtmlKeywords(objHandle: HCkSpider): PWideChar; stdcall;
The HTML META keywords from the last page fetched by the spider.
See the notes about PWideChar memory ownership and validity.
LastHtmlTitle
function CkSpider__lastHtmlTitle(objHandle: HCkSpider): PWideChar; stdcall;
The HTML title from the last page fetched by the spider.
See the notes about PWideChar memory ownership and validity.
LastMethodSuccess
procedure CkSpider_putLastMethodSuccess(objHandle: HCkSpider; newPropVal: wordbool); stdcall;
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.
LastModDateStr
function CkSpider__lastModDateStr(objHandle: HCkSpider): PWideChar; stdcall;
The last modification date/time (RFC822 format) from the last page fetched by the spider.
See the notes about PWideChar memory ownership and validity.
topLastUrl
function CkSpider__lastUrl(objHandle: HCkSpider): PWideChar; stdcall;
MaxResponseSize
procedure CkSpider_putMaxResponseSize(objHandle: HCkSpider; newPropVal: Integer); stdcall;
The maximum HTTP response size allowed. The spider will automatically fail any pages larger than this size. The default value is 250,000 bytes.
MaxUrlLen
procedure CkSpider_putMaxUrlLen(objHandle: HCkSpider; newPropVal: Integer); stdcall;
The maximum URL length allowed. URLs longer than this are not added to the unspidered list. The default value is 200.
NumAvoidPatterns
The number of avoid patterns previously set by calling AddAvoidPattern.
topNumFailed
The number of URLs in the object's failed URL list.
topNumOutboundLinks
The number of URLs in the object's outbound links URL list.
topNumSpidered
The number of URLs in the object's already-spidered URL list.
topNumUnspidered
PreferIpv6
procedure CkSpider_putPreferIpv6(objHandle: HCkSpider; newPropVal: wordbool); stdcall;
If True
, then use IPv6 over IPv4 when both are supported for a particular domain. The default value of this property is False
, which will choose IPv4 over IPv6.
ProxyDomain
procedure CkSpider_putProxyDomain(objHandle: HCkSpider; newPropVal: PWideChar); stdcall;
function CkSpider__proxyDomain(objHandle: HCkSpider): PWideChar; stdcall;
The domain name of a proxy host if an HTTP proxy is used.
See the notes about PWideChar memory ownership and validity.
topProxyLogin
procedure CkSpider_putProxyLogin(objHandle: HCkSpider; newPropVal: PWideChar); stdcall;
function CkSpider__proxyLogin(objHandle: HCkSpider): PWideChar; stdcall;
If an HTTP proxy is used and it requires authentication, this property specifies the HTTP proxy login.
See the notes about PWideChar memory ownership and validity.
topProxyPassword
procedure CkSpider_putProxyPassword(objHandle: HCkSpider; newPropVal: PWideChar); stdcall;
function CkSpider__proxyPassword(objHandle: HCkSpider): PWideChar; stdcall;
If an HTTP proxy is used and it requires authentication, this property specifies the HTTP proxy password.
See the notes about PWideChar memory ownership and validity.
topProxyPort
procedure CkSpider_putProxyPort(objHandle: HCkSpider; newPropVal: Integer); stdcall;
The port number of a proxy server if an HTTP proxy is used.
topReadTimeout
procedure CkSpider_putReadTimeout(objHandle: HCkSpider; newPropVal: Integer); stdcall;
The maximum number of seconds to wait when reading from an HTTP server.
topUpdateCache
procedure CkSpider_putUpdateCache(objHandle: HCkSpider; newPropVal: wordbool); stdcall;
If equal to 1 (true) then pages saved to the cache. If 0, the cache is ignored. The default value is 1. Regardless, if no CacheDir is set then the cache is not used.
UserAgent
procedure CkSpider_putUserAgent(objHandle: HCkSpider; newPropVal: PWideChar); stdcall;
function CkSpider__userAgent(objHandle: HCkSpider): PWideChar; stdcall;
The value of the HTTP user-agent header field to be sent with HTTP requests. This can be set to any desired value, but be aware that some websites may reject requests from unknown user agents.
See the notes about PWideChar memory ownership and validity.
topVerboseLogging
procedure CkSpider_putVerboseLogging(objHandle: HCkSpider; newPropVal: wordbool); stdcall;
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
function CkSpider__version(objHandle: HCkSpider): PWideChar; stdcall;
Version of the component/library, such as "10.1.0"
See the notes about PWideChar memory ownership and validity.
WasRedirected
Indicates whether the last URL crawled was redirected. (True
= yes, False
= no)
WindDownCount
procedure CkSpider_putWindDownCount(objHandle: HCkSpider; newPropVal: Integer); stdcall;
The wind-down
phase begins when this number of URLs has been spidered. When in the wind-down phase, no new URLs are added to the unspidered list. The default value is 0 which means that there is NO wind-down phase.
Methods
AddAvoidOutboundLinkPattern
pattern: PWideChar) stdcall;
Adds a wildcarded pattern to prevent collecting matching outbound link URLs. For example, if *google*
is added, then any outbound links containing the word google
will be ignored. The *
character matches zero or more of any character.
AddAvoidPattern
pattern: PWideChar) stdcall;
Adds a wildcarded pattern to prevent spidering matching URLs. For example, if *register*
is added, then any url containing the word register
is not spidered. The *
character matches zero or more of any character.
AddMustMatchPattern
pattern: PWideChar) stdcall;
Adds a wildcarded pattern to limit spidering to only URLs that match the pattern. For example, if */products/*
is added, then only URLs containing /products/
are spidered. This is helpful for only spidering a portion of a website. The *
character matches zero or more of any character.
AddUnspidered
url: PWideChar) stdcall;
To begin spidering you must call this method one or more times to provide starting points. It adds a single URL to the object's internal queue of URLs to be spidered.
CanonicalizeUrl
url: PWideChar;
outStr: HCkString): wordbool; stdcall;
function CkSpider__canonicalizeUrl(objHandle: HCkSpider;
url: PWideChar): PWideChar; stdcall;
Canonicalizes a URL by doing the following:
- Drops username/password if present.
- Drops fragment if present.
- Converts domain to lowercase.
- Removes port 80 or 443
- Remove default.asp, index.html, index.htm, default.html, index.htm, default.htm, index.php, index.asp, default.php, .cfm, .aspx, ,php3, .pl, .cgi, .txt, .shtml, .phtml
- Remove www. from the domain if present.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
ClearFailedUrls
Clears the object's internal list of URLs that could not be downloaded.
topClearOutboundLinks
Clears the object's internal list of outbound URLs that will automatically accumulate while spidering.
topClearSpideredUrls
Clears the object's internal list of already-spidered URLs that will automatically accumulate while spidering.
topCrawlNext
Crawls the next URL in the internal list of unspidered URLs. The URL is moved from the unspidered list to the spidered list. Any new links within the same domain and not yet spidered are added to the unspidered list. (providing that they do not match avoid
patterns, etc.) Any new outbound links are added to the outbound URL list.
If successful, the HTML of the downloaded page is available in the LastHtml property. If there are no more URLs left unspidered, the method returns False
. Information about the URL crawled is available in the properties LastUrl, LastFromCache, and LastModDate.
CrawlNextAsync (1)
Creates an asynchronous task to call the CrawlNext method with the arguments provided.
Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.
Returns nil
on failure
FetchRobotsText
outStr: HCkString): wordbool; stdcall;
function CkSpider__fetchRobotsText(objHandle: HCkSpider): PWideChar; stdcall;
Returns the contents of the robots.txt file from the domain being crawled. This spider object will not crawl URLs excluded by robots.txt. If you believe the spider is not behaving correctly, please notify us at support@chilkatsoft.com and provide information detailing a case that allows us to reproduce the problem.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
FetchRobotsTextAsync (1)
Creates an asynchronous task to call the FetchRobotsText method with the arguments provided.
Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.
Returns nil
on failure
GetAvoidPattern
index: Integer;
outStr: HCkString): wordbool; stdcall;
function CkSpider__getAvoidPattern(objHandle: HCkSpider;
index: Integer): PWideChar; stdcall;
Returns the Nth avoid pattern previously added by calling AddAvoidPattern. Indexing begins at 0.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
topGetBaseDomain
domain: PWideChar;
outStr: HCkString): wordbool; stdcall;
function CkSpider__getBaseDomain(objHandle: HCkSpider;
domain: PWideChar): PWideChar; stdcall;
Returns the second-level + top-level domain of the domain. For example, if domain is xyz.example.com
, this returns example.com
. For some domains, such as xyz.example.co.uk
, the top 3 levels are returned, such as example.co.uk
.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
GetFailedUrl
index: Integer;
outStr: HCkString): wordbool; stdcall;
function CkSpider__getFailedUrl(objHandle: HCkSpider;
index: Integer): PWideChar; stdcall;
Returns the Nth URL in the failed URL list. Indexing begins at 0.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
topGetOutboundLink
index: Integer;
outStr: HCkString): wordbool; stdcall;
function CkSpider__getOutboundLink(objHandle: HCkSpider;
index: Integer): PWideChar; stdcall;
Returns the Nth URL in the outbound link URL list. Indexing begins at 0.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
topGetSpideredUrl
index: Integer;
outStr: HCkString): wordbool; stdcall;
function CkSpider__getSpideredUrl(objHandle: HCkSpider;
index: Integer): PWideChar; stdcall;
Returns the Nth URL in the already-spidered URL list. Indexing begins at 0.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
topGetUnspideredUrl
index: Integer;
outStr: HCkString): wordbool; stdcall;
function CkSpider__getUnspideredUrl(objHandle: HCkSpider;
index: Integer): PWideChar; stdcall;
Returns the Nth URL in the unspidered URL list. Indexing begins at 0.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
topGetUrlDomain
url: PWideChar;
outStr: HCkString): wordbool; stdcall;
function CkSpider__getUrlDomain(objHandle: HCkSpider;
url: PWideChar): PWideChar; stdcall;
Returns the domain name part of a URL. For example, if the URL is https://www.chilkatsoft.com/test.asp
, then www.chilkatsoft.com
is returned.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
topInitialize
domain: PWideChar) stdcall;
Initializes the object to begin spidering a domain. Calling Initialize clears any patterns added via the AddAvoidOutboundLinkPattern, AddAvoidPattern, and AddMustMatchPattern methods. The domain name passed to this method is what is returned by the Domain property. The spider only crawls URLs within the same domain.
LoadTaskCaller
RecrawlLast
Re-crawls the last URL spidered. This helpful when cookies set in a previous page load cause the page to be loaded differently the next time.
topRecrawlLastAsync (1)
Creates an asynchronous task to call the RecrawlLast method with the arguments provided.
Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.
Returns nil
on failure
SkipUnspidered
index: Integer) stdcall;
Moves a URL from the unspidered list to the spidered list. This allows an application to skip a specific URL.
topSleepMs
numMilliseconds: Integer) stdcall;
Suspends the execution of the current thread until the time-out interval elapses.
topEvents
AbortCheck
Enables a method call to be aborted by triggering the AbortCheck event at intervals defined by the HeartbeatMs
property. If HeartbeatMs is set to its default value of 0, no events will occur. For instance, set HeartbeatMs to 200 to trigger 5 AbortCheck events per second. Return True
to abort; return False
to continue (not abort)
PercentDone
This provides the percentage completion for any method involving network communications or time-consuming processing, assuming the progress can be measured as a percentage. This event is triggered only when it's possible and logical to express the operation's progress as a percentage. The pctDone argument will range from 1 to 100. For methods that finish quickly, the number of PercentDone callbacks may vary, but the final callback will have pctDone equal to 100. For longer operations, callbacks will not exceed one per percentage point (e.g., 1, 2, 3, ..., 98, 99, 100).
The PercentDone callback also acts as an AbortCheck
event. For fast methods where PercentDone fires, an AbortCheck event may not trigger since the PercentDone callback already provides an opportunity to abort. For longer operations, where time between PercentDone callbacks is extended, AbortCheck callbacks enable more responsive operation termination.
Return True
to abort; return False
to continue (not abort)
ProgressInfo
This event callback provides tag name
/value pairs that detail what occurs during a method call. To discover existing tag names, create code to handle the event, emit the pairs, and review them. Most tag names are self-explanatory.
TaskCompleted
Called from the background thread when an asynchronous task completes.