HTTP Client (cl_http)

SMACC2 client library for making HTTP/HTTPS requests using Boost.Beast.

Architecture

/home/brettpac/workspaces/isaac_ros-dev/src/SMACC2/smacc2_client_library/cl_http The cl_http follows a pure component-based architecture with three specialized components:

ClHttp (Client - Orchestrator)
├── CpHttpConnectionManager - io_context and thread management
├── CpHttpSessionManager - SSL context and session creation
└── CpHttpRequestExecutor - Request execution and response handling

Components

CpHttpConnectionManager

Responsibility: Manages the asynchronous I/O infrastructure

• Owns boost::asio::io_context
• Manages worker thread lifecycle
• Provides strand for thread-safe operations

Lifetime: State machine scoped (created with ClHttp, destroyed with state machine)

CpHttpSessionManager

Responsibility: Manages HTTP/HTTPS session configuration

• Parses server URLs (protocol, host, port)
• Manages SSL context for HTTPS connections
• Creates session objects (http_session or ssl_http_session)

Lifetime: State machine scoped

CpHttpRequestExecutor

Responsibility: Coordinates HTTP request execution

• Accepts request parameters (method, path, body, headers)
• Acquires strand from CpHttpConnectionManager
• Acquires session from CpHttpSessionManager
• Executes requests and emits response signals

Lifetime: State machine scoped

Signal Flow

User Code (Behavior)
    ↓
CpHttpRequestExecutor::executeRequest()
    ↓
Session created (http_session/ssl_http_session)
    ↓
Request executed asynchronously
    ↓
Response received
    ↓
CpHttpRequestExecutor::onResponseReceived_ (SmaccSignal)
    ↓ (backward compatibility)
ClHttp::onResponseReceived_ (forwarded)
    ↓
Behavior callback

Usage

Quick Start: Using Base Behaviors

The easiest way to make HTTP requests is using the provided base behaviors:

#include <cl_http/client_behaviors/cb_http_get_request.hpp>

class StHttpRequest : public smacc2::SmaccState<StHttpRequest, SmExample>
{
public:
  using SmaccState::SmaccState;

  void runtimeConfigure() override
  {
    auto behavior = this->configure<cl_http::CbHttpGetRequest>();
  }
};

Custom Behaviors: Component-Based Approach

For custom HTTP behavior, inherit from base class and override response handling:

```cpp #include <cl_http/client_behaviors/cb_http_request.hpp>

class CbCustomRequest : public cl_http::CbHttpRequestBase { public: CbCustomRequest() : CbHttpRequestBase(CpHttpRequestExecutor::HttpMethod::GET) {}

void onResponseReceived(const CpHttpRequestExecutor::TResponse& response) override {

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Changelog for package cl_http

2.3.19 (2025-06-17)

• OpenAI example client ported to SMACC (#557)

  • initial commit for openAI example
  • Replaced get with post, added key fetch logic
  • Added ability to modify the body of an http request for the http client
  • Added functionality to encode and send image data to ChatGPT
  • Added APIs to add headers to an outgoing HTTP request
  • HTTP requests can now deal with CDNs

  * Expanded example openAI node to submit a more sophisticated request with an image

  • Using env variable for test iamge location
  • Fixed commit errors
  • Renamed instantiation of HTTP request CB to something more specific to OpenAI

• Moved HTTP client behaviour to client library. Also added GET and POS… (#549)

  • Moved HTTP client behaviour to client library. Also added GET and POST-specific versions of the smacc HTTP client behaviour to make them easier to use
  • Added copyrights
  • Fixed typos

• Http client (#522)

  • Ported http work over from smacc1
  • Added example showasing http requests
  • Fixed some typos in the HTTP example
  • Made provision for HTTP GET/POST in the HTTP client
  • Moved HTTP client into the client_libraries folder and made separate compilation units. Modified examples to use this new client

  * Update smacc_action_client_base.hpp Pretty sure this change was made accidently.

  * Update smacc_action_client_base.hpp Messed up first commit

  * Update http_client.cpp Added License to file to clean up format error

  * Update http_client.cpp Found better Copyright & License for CI Format error.

  * Update cb_http_request.hpp Another little format error

  * Update sm_atomic_http.py Somehow a bracket became a cNode

  • • Fixed errors with HTTP requests not triggering,

  • Fixed response callback not triggering correctly and causing a crash

  • Fixed example not transitioning back to state 1 after a response has been received

  • Ported http work over from smacc1

  • Added example showasing http requests

  • Fixed some typos in the HTTP example

  • Made provision for HTTP GET/POST in the HTTP client

  • Moved HTTP client into the client_libraries folder and made separate compilation units. Modified examples to use this new client

  * Update http_client.cpp Added License to file to clean up format error

  * Update http_client.cpp Found better Copyright & License for CI Format error.

  * Update cb_http_request.hpp Another little format error

  * Update sm_atomic_http.py Somehow a bracket became a cNode

  • • Fixed errors with HTTP requests not triggering,

  • Fixed response callback not triggering correctly and causing a crash

  • Fixed example not transitioning back to state 1 after a response has been received

  • Added helper class to handle server name related interactions

  • Added SSL implementation, need to make provision for SSL and non-SSLD requests

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