HttpCurl Delphi DLL Reference Documentation
HttpCurl
Current Version: 11.4.0
A class for running curl commands within your application. Mirrors the curl command syntax. It is not derived from curl/libcurl, and does not wrap libcurl.
Create/Dispose
var myObject: HCkHttpCurl; begin myObject := CkHttpCurl_Create(); // ... CkHttpCurl_Dispose(myObject); end;
Creates an instance of the HCkHttpCurl 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 CkHttpCurl_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function.
Properties
DebugLogFilePath
procedure CkHttpCurl_putDebugLogFilePath(objHandle: HCkHttpCurl; newPropVal: PWideChar); stdcall;
function CkHttpCurl__debugLogFilePath(objHandle: HCkHttpCurl): 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.
EnableBodyVars
procedure CkHttpCurl_putEnableBodyVars(objHandle: HCkHttpCurl; newPropVal: wordbool); stdcall;
Enables variable substitution in the body of the request. The default value is True.
LastErrorHtml
function CkHttpCurl__lastErrorHtml(objHandle: HCkHttpCurl): 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 CkHttpCurl__lastErrorText(objHandle: HCkHttpCurl): 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 CkHttpCurl__lastErrorXml(objHandle: HCkHttpCurl): 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.
topLastMethodSuccess
procedure CkHttpCurl_putLastMethodSuccess(objHandle: HCkHttpCurl; 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. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.
ResponseBodyStr
function CkHttpCurl__responseBodyStr(objHandle: HCkHttpCurl): PWideChar; stdcall;
Returns the HTTP response body from the last call to DoYourThing .
See the notes about PWideChar memory ownership and validity.
topResponseFilePath
procedure CkHttpCurl_putResponseFilePath(objHandle: HCkHttpCurl; newPropVal: PWideChar); stdcall;
function CkHttpCurl__responseFilePath(objHandle: HCkHttpCurl): PWideChar; stdcall;
Set this property to the path of a file to stream the response body to a file. If the response is streamed to a file, it will not be available in ResponseBodyStr , GetResponseSb , or GetResponseBd .
See the notes about PWideChar memory ownership and validity.
topStatusCode
Returns the HTTP status code from the last call to DoYourThing. A value of 0 indicates no response header was received.
VerboseLogging
procedure CkHttpCurl_putVerboseLogging(objHandle: HCkHttpCurl; 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 CkHttpCurl__version(objHandle: HCkHttpCurl): PWideChar; stdcall;
Version of the component/library, such as "10.1.0"
See the notes about PWideChar memory ownership and validity.
Methods
AddFunction
funcName: PWideChar;
curl: PWideChar): wordbool; stdcall;
Adds a named curl function that can be used in dependency resolution. Inputs required by the curl function are indicated by the variable names enclosed in {{ and }}. Outputs are defined in one or more calls to AddOutput .
Returns True for success, False for failure.
topAddOutput
funcName: PWideChar;
jsonPath: PWideChar;
varName: PWideChar): wordbool; stdcall;
Adds a defined output for a dependency resolution curl function previously defined by calling AddFunction. The jsonPath is the JSON path in the JSON response body where the varName's value is located.
Returns True for success, False for failure.
topAddTargetOutput
jsonPath: PWideChar;
varName: PWideChar) stdcall;
Adds an automatically mapped variable for the target curl command. When a JSON response is received from a curl request, the value at the JSON path specified by jsonPath is extracted (if present) and assigned to the variable named by varName.
This is useful in common workflows where one request returns an identifier (such as an `id`) that must be reused in a subsequent curl request.
Returns True for success, False for failure.
topClearTargetOutput
varName: PWideChar) stdcall;
Clears (undefines) the target output for the specified varName. If varName equals "*", then all target outputs are cleared.
ClearVar
varName: PWideChar) stdcall;
Undefines the variable with the specified name. If varName equals "*", then all variables are cleared.
Returns True for success, False for failure.
topDoYourThing
targetCurl: PWideChar): wordbool; stdcall;
Runs a the curl command specified in targetCurl. Returns success (True) if a response was received, in which case the response status code will be available in StatusCode and the content of the response body will be available in one of two places:
- If
ResponseFilePathis non-empty, the response body was streamed to the specified file path. - If
ResponseFilePathis empty, the response body can be retrieved viaResponseBodyStr,GetResponseSb, orGetResponseBd. Binary responses should only be retrieved viaResponseBodyBd.
Assuming the HTTP response is JSON, the target outputs (variables) specified by prior calls to AddTargetOutput will be populated by applying each variable's JSON path to the response JSON.
Returns True for success, False for failure.
topDoYourThingAsync (1)
targetCurl: PWideChar): HCkTask; stdcall;
Creates an asynchronous task to call the DoYourThing 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
ExaminePlan
curl: PWideChar;
outStr: HCkString): wordbool; stdcall;
function CkHttpCurl__examinePlan(objHandle: HCkHttpCurl;
curl: PWideChar): PWideChar; stdcall;
Used for debugging. Returns a string that provides information about the plan of execution that would occur for the curl based on the variables that are either unknown or already known. The plan of execution is what would occur if DoYourThing was called with the current state of knowledge.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
topGetAllVars
Returns all defined variables in json.
topGetResponseBd
Writes to bd the HTTP response body from the last call to DoYourThing.
Returns True for success, False for failure.
topGetResponseJarr
Writes to jarr the HTTP response body from the last call to DoYourThing.
Returns True for success, False for failure.
topGetResponseJson
json: HCkJsonObject): wordbool; stdcall;
Writes to json the HTTP response body from the last call to DoYourThing.
Returns True for success, False for failure.
topGetResponseSb
Writes to sb the HTTP response body from the last call to DoYourThing.
Returns True for success, False for failure.
topGetResponseXml
Writes to xml the HTTP response body from the last call to DoYourThing.
Returns True for success, False for failure.
topGetVar
varName: PWideChar;
outStr: HCkString): wordbool; stdcall;
function CkHttpCurl__getVar(objHandle: HCkHttpCurl;
varName: PWideChar): PWideChar; stdcall;
Retrieves the current value of the variable specified by varName.
Returns True for success, False for failure.
See the notes about PWideChar memory ownership and validity.
topSetAuth
Sets authorization information that is applied to all calls to DoYourThing . See the examples below for details.
Returns True for success, False for failure.
topSetVar
varName: PWideChar;
varValue: PWideChar) stdcall;
Sets the value of a variable to be replaced in curl commands. Variable names are enclosed in {{ and }} and can occur in the path, query params, or the body of the request.
Returns True for success, False for failure.
ToRawRequest
curlCommand: PWideChar;
sb: HCkStringBuilder): wordbool; stdcall;
Used for debugging purposes. This method behaves the same as DoYourThing , but only converts the curlCommand to an HTTP request message in sb containing the full structure:
- start line
- headers
- optional body or multipart body
It does not actually send the HTTP request.
Returns True for success, False for failure.
topVarDefined
varName: PWideChar): wordbool; stdcall;
Returns True if the varName is defined, otherwise returns False. Setting varName to "!" checks whether all target output variables have been defined. It returns True if every target output is set, and False if any are missing.
Events
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.