Table of Contents

HttpClientAbstract

Namespace
ZAux
Implements
FUNCTION_BLOCK ABSTRACT HttpClientAbstract IMPLEMENTS ZCore.IHttpClient, ZCore.IObject, ZCore.IError

Used to send HTTP requests and receiving HTTP responses from a resource identified by a URI.

Note

The TwinCAT implementation of HttpClient, additionally to Zeugwerk Framework, requires an installation of Zeugwerk HttpClientProxy on a computer in your local network and an ADS route to this server. For questions, contact the support.

Properties

Busy 

PROPERTY Busy : BOOL

This property returns TRUE if the object is Busy executing a sequence or still in its initialization phase (if applicable). It returns FALSE if the object is Idle or in an Error state.

Use State to find out if the object is busy executing its initialization phase, or it is busy performing an actual sequence.

Property Value

BOOL

Done 

PROPERTY Done : BOOL

If the object is in idle state (often mentioned as "the object is not busy and not on error"), this is indicated by this property returning TRUE.

Property Value

BOOL

StatusCode 

PROPERTY StatusCode : ZCore.HttpClientStatusCode

This property returns the statuscode of a server's response. The value is only valid if Busy=FALSE.

Property Value

HttpClientStatusCode

Methods

GetAsync 

METHOD GetAsync (
 [input] startToken : ZCore.IStartToken,
 [input] uri : STRING(ZCore.ParameterList.MaxHttpClientUriLength),
 [input] responseBuffer : ZCore.ZPointer,
 [input] responseSize : UDINT)

Send a GET request to the specified Uri as an asynchronous operation. Use Busy property and its derivatives to retrieve the status of the asynchronous operation. As soon as Busy=FALSE the StatusCode method can be used to check if the request was successful (StatusCode=200) or not. The response of the GET request is written to the responseBuffer, which is passed as a parameter to this method. Make sure that the buffer size is big enough for the response, which is returned by the server.

Inputs

startToken IStartToken
uri STRING(ZCore.ParameterList.MaxHttpClientUriLength)
responseBuffer ZPointer
responseSize UDINT

PostAsync 

METHOD PostAsync (
 [input] startToken : ZCore.IStartToken,
 [input] uri : STRING(ZCore.ParameterList.MaxHttpClientUriLength),
 [input] payloadBuffer : ZCore.ZPointer,
 [input] payloadSize : UDINT)

Send a POST request to the specified Uri as an asynchronous operation. Use Busy property and its derivatives to retrieve the status of the asynchronous operation. As soon as Busy=FALSE the StatusCode method can be used to check if the request was successful (StatusCode=200) or not. The payload that should be send to the server is is passed as a parameter to this method.

Inputs

startToken IStartToken
uri STRING(ZCore.ParameterList.MaxHttpClientUriLength)
payloadBuffer ZPointer
payloadSize UDINT

SetHttpClientProxy 

METHOD SetHttpClientProxy (
 [input] on : BOOL,
 [input] target : STRING)

This method is used to set a server, which acts as a proxy for the PLC. Refer to the implementation to get more details about this.

Inputs

on BOOL

Use proxy (on:=TRUE) or try to use native mode (on:=FALSE)

target STRING

TraceErrorStack 

METHOD TraceErrorStack (
 [input] trace : ZCore.IErrorTrace)

This method is used internally when recording an error trace.

Inputs

trace IErrorTrace