HttpCurl Xojo Plugin Reference Documentation

HttpCurl

Current Version: 11.4.0

Requires Chilkat Bundle License

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

Dim httpCurl As New Chilkat.HttpCurl

Properties

DebugLogFilePath

DebugLogFilePath As String

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

Example showing how to use DebugLogFilePath.

EnableBodyVars

EnableBodyVars As Boolean

Introduced in version 11.5.0

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

More Information and Examples

curl with Variable Substitution in the Request Body

LastErrorHtml

LastErrorHtml As String (read-only)

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.

LastErrorText

LastErrorText As String (read-only)

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.

More Information and Examples

Concept of LastErrorText LastErrorText Standard Information

LastErrorXml

LastErrorXml As String (read-only)

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.

LastMethodSuccess

LastMethodSuccess As Boolean

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

ResponseBodyStr As String (read-only)

Introduced in version 11.5.0

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

ResponseFilePath

ResponseFilePath As String

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 .

StatusCode

StatusCode As Int32 (read-only)

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.

VerboseLogging

VerboseLogging As Boolean

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

Version As String (read-only)

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

More Information and Examples

How to get the Chilkat version at runtime.

Methods

AddFunction

Function AddFunction(funcName As String, curl As String) As 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.

AddOutput

Function AddOutput(funcName As String, jsonPath As String, varName As String) As 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.

AddTargetOutput

Sub AddTargetOutput(jsonPath As String, varName As String)

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.

ClearTargetOutput

Sub ClearTargetOutput(varName As String)

Introduced in version 11.5.0

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

ClearVar

Sub ClearVar(varName As String)

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.

DoYourThing

Function DoYourThing(targetCurl As String) As 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:

If ResponseFilePath is non-empty, the response body was streamed to the specified file path.
If ResponseFilePath is empty, the response body can be retrieved via ResponseBodyStr , GetResponseSb , or GetResponseBd . Binary responses should only be retrieved via ResponseBodyBd .

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.

DoYourThingAsync ⁽¹⁾

Function DoYourThingAsync(targetCurl As String) As Chilkat.Task

Introduced in version 11.5.0

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

Function ExaminePlan(curl As String) As String

Introduced in version 11.5.0

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 Nil on failure

GetAllVars

Sub GetAllVars(json As Chilkat.JsonObject)

Introduced in version 11.5.0

Returns all defined variables in json.

GetResponseBd

Function GetResponseBd(bd As Chilkat.BinData) As 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.

GetResponseJarr

Function GetResponseJarr(jarr As Chilkat.JsonArray) As 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.

GetResponseJson

Function GetResponseJson(json As Chilkat.JsonObject) As 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.

GetResponseSb

Function GetResponseSb(sb As Chilkat.StringBuilder) As 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.

GetResponseXml

Function GetResponseXml(xml As Chilkat.Xml) As 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.

GetVar

Function GetVar(varName As String) As String

Introduced in version 11.5.0

Retrieves the current value of the variable specified by varName.

Returns Nil on failure

SetAuth

Function SetAuth(json As Chilkat.JsonObject) As 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.

SetVar

Sub SetVar(varName As String, varValue As String)

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.

More Information and Examples

curl with Path Variables and Query Params curl with Variable Substitution in the Request Body

ToRawRequest

Function ToRawRequest(curlCommand As String, sb As Chilkat.StringBuilder) As 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.

VarDefined

Function VarDefined(varName As String) As 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.

Events

To implement events, your application would define and implement a class that is a subclass of Chilkat.HttpCurl. Your custom class would implement (i.e. override) some or all of the event methods.

For example:

class MyHttpCurl
    Inherits Chilkat.HttpCurl

    Function AbortCheck() As Boolean

    Function PercentDone(pctDone As Int32) As Boolean

    Sub ProgressInfo(name As String, value As String)

    Sub TaskCompleted(task As Chilkat.Task)


End Class

AbortCheck

Function AbortCheck() As Boolean

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.

More Information and Examples

Chilkat Event Callback Examples

PercentDone

Function PercentDone(pctDone As Int32) As Boolean

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.

To abort the operation, set the abort output argument to True. This will cause the method to terminate and return a failure status or corresponding failure value.

More Information and Examples

Chilkat Event Callback Examples

ProgressInfo

Sub ProgressInfo(name As String, value As String)

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.

More Information and Examples

Chilkat Event Callback Examples

TaskCompleted

Sub TaskCompleted(task As Chilkat.Task)

Called from the background thread when an asynchronous task completes.

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