HttpCurl DataFlex 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.

Object Creation

// (Dataflex programs use the 32-bit Chilkat ActiveX)
Handle hoHttpCurl
Get Create(RefClass(cComChilkatHttpCurl)) to hoHttpCurl

Properties

DebugLogFilePath
Function ComDebugLogFilePath Returns String
Procedure Set ComDebugLogFilePath String value

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.

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EnableBodyVars
Function ComEnableBodyVars Returns Boolean
Procedure Set ComEnableBodyVars Boolean value
Introduced in version 11.5.0

Enables variable substitution in the body of the request. The default value is True.

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FailedCurl
Function ComFailedCurl Returns String
Introduced in version 11.5.0

Set to the specific curl command in the execution plan that failed.

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FailReason
Function ComFailReason Returns Integer
Introduced in version 11.5.0

Set to an integer value indicating the reason for failure for the methods DoYourThing and ExaminePlan

Possible values are:

  1. No error - the method succeeded or hasn't yet been called.
  2. curl command syntax error.
  3. HTTP response status code indidcates an authentication (401) or authorization (403) error.
  4. HTTP response status code indicates an error, but not an authentication or authorization error.
  5. HTTP communications failure.
  6. Impossible to derive an execution plan from defined outputs and inputs.
  7. A step in the execution plan did not resolve any dependency variables.
  8. Failed to get curl data from a local file source (see the note below).
  9. If we are within a Chilkat.Js context and don't have permission to read the local filesystem.
  10. Chilkat has not been successfully unlocked by previously and successfully calling UnlockBundle.

Note: curl can read data from a local file and send it in a request (usually POST/PUT) using special syntax:

  • -d @file.txt → reads the file and sends it as request body (form-style encoding).
  • --data-binary @file.bin → sends raw file contents exactly as-is.
  • -F "file=@file.txt" → uploads the file as multipart/form-data.

The @ tells curl to load the data from a local file instead of using a literal string.

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LastBinaryResult
Function ComLastBinaryResult Returns Variant

This property is mainly used in SQL Server stored procedures to retrieve binary data from the last method call that returned binary data. It is only accessible if Chilkat.Global.KeepBinaryResult is set to True. This feature allows for the retrieval of large varbinary results in an SQL Server environment, which has restrictions on returning large data via method calls, though temp tables can handle binary properties.

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LastErrorHtml
Function ComLastErrorHtml Returns String

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.

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LastErrorText
Function ComLastErrorText Returns String

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.

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LastErrorXml
Function ComLastErrorXml Returns String

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.

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LastMethodSuccess
Function ComLastMethodSuccess Returns Boolean
Procedure Set ComLastMethodSuccess Boolean value

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.

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LastStringResult
Function ComLastStringResult Returns String

In SQL Server stored procedures, this property holds the string return value of the most recent method call that returns a string. It is accessible only when Chilkat.Global.KeepStringResult is set to TRUE. SQL Server has limitations on string lengths returned from methods and properties, but temp tables can be used to access large strings.

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LastStringResultLen
Function ComLastStringResultLen Returns Integer

The length, in characters, of the string contained in the LastStringResult property.

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ResponseBodyStr
Function ComResponseBodyStr Returns String
Introduced in version 11.5.0

Returns the HTTP response body from the last call to DoYourThing .

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ResponseFilePath
Function ComResponseFilePath Returns String
Procedure Set ComResponseFilePath String value
Introduced in version 11.5.0

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 .

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StatusCode
Function ComStatusCode Returns Integer
Introduced in version 11.5.0

Returns the HTTP status code from the last call to DoYourThing. A value of 0 indicates no response header was received.

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VerboseLogging
Function ComVerboseLogging Returns Boolean
Procedure Set ComVerboseLogging Boolean value

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
Function ComVersion Returns String

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

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Methods

AddFunction
Function ComAddFunction String funcName String curl Returns Boolean
Introduced in version 11.5.0

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.

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AddOutput
Function ComAddOutput String funcName String jsonPath String varName Returns Boolean
Introduced in version 11.5.0

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.

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AddTargetOutput
Procedure ComAddTargetOutput String jsonPath String varName
Introduced in version 11.5.0

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.

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ClearTargetOutput
Procedure ComClearTargetOutput String varName
Introduced in version 11.5.0

Clears (undefines) the target output for the specified varName. If varName equals "*", then all target outputs are cleared.

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ClearVar
Procedure ComClearVar String varName
Introduced in version 11.5.0

Undefines the variable with the specified name. If varName equals "*", then all variables are cleared.

Returns True for success, False for failure.

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DoYourThing
Function ComDoYourThing String targetCurl Returns Boolean
Introduced in version 11.5.0

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:

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.

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DoYourThingAsync (1)
Function ComDoYourThingAsync String targetCurl Returns cComChilkatTask
Introduced in version 11.5.0

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

Returns null on failure

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ExaminePlan
Function ComExaminePlan String curl cComChilkatJsonObject json Returns Boolean
Introduced in version 11.5.0

Used for debugging. Returns in json 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.

If no execution plan is possible with the current known inputs and outputs, then json provides information about what is missing and the method returns False.

Returns True for success, False for failure.

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GetAllVars
Procedure ComGetAllVars cComChilkatJsonObject json
Introduced in version 11.5.0

Returns all defined variables in json.

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GetResponseBd
Function ComGetResponseBd cComChilkatBinData bd Returns Boolean
Introduced in version 11.5.0

Writes to bd the HTTP response body from the last call to DoYourThing.

Returns True for success, False for failure.

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GetResponseJarr
Function ComGetResponseJarr cComChilkatJsonArray jarr Returns Boolean
Introduced in version 11.5.0

Writes to jarr the HTTP response body from the last call to DoYourThing.

Returns True for success, False for failure.

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GetResponseJson
Function ComGetResponseJson cComChilkatJsonObject json Returns Boolean
Introduced in version 11.5.0

Writes to json the HTTP response body from the last call to DoYourThing.

Returns True for success, False for failure.

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GetResponseSb
Function ComGetResponseSb cComChilkatStringBuilder sb Returns Boolean
Introduced in version 11.5.0

Writes to sb the HTTP response body from the last call to DoYourThing.

Returns True for success, False for failure.

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GetResponseXml
Function ComGetResponseXml cComChilkatXml xml Returns Boolean
Introduced in version 11.5.0

Writes to xml the HTTP response body from the last call to DoYourThing.

Returns True for success, False for failure.

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GetVar
Function ComGetVar String varName Returns String
Introduced in version 11.5.0

Retrieves the current value of the variable specified by varName.

Returns null on failure

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SetAuth
Function ComSetAuth cComChilkatJsonObject json Returns Boolean
Introduced in version 11.5.0

Sets authorization information that is applied to all calls to DoYourThing . See the examples below for details.

Returns True for success, False for failure.

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SetVar
Procedure ComSetVar String varName String varValue
Introduced in version 11.5.0

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.

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ToRawRequest
Function ComToRawRequest String curlCommand cComChilkatStringBuilder sb Returns Boolean
Introduced in version 11.5.0

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.

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VarDefined
Function ComVarDefined String varName Returns Boolean
Introduced in version 11.5.0

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.

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