How to write APIs for C++ SDK Appwrite?

[pooranjoyb]

Few things to know before writing a new API for the SDK :

• C++ SDK doesn't officially exist for Appwrite, hence we're doing it ourselves.
• We'll have to maintain the code-quality and SDK structure that Appwrite follows in their SDK repositories.
• Coding's gonna be hard, so learn basic OOPs concepts.

Now say we need to write a new api called getTopic which is a part of Messaging module.

• Firstly we'll check the Official API reference how they're calling the API.
• Then, we'll go to existing Appwrite SDKs repository (say Python-SDK, JS-SDK) and see how they've implemented that API.

For your reference
https://github.com/appwrite/sdk-for-python/blob/503de4b759c7b2611281c019d78e11aed47644f0/appwrite/services/messaging.py#L1881-L1911

• Once we get an idea of the parameters/api-endpoint etc; we'll start writing our own api-code.
• Based on our research of the API we're working on, we'll declare the API in the respective module with necessary parameters.

For your reference

cpp-sdk-appwrite/include/classes/Messaging.hpp

Line 17 in 4f812f5

std::string getTopic(const std::string &topicId);

• Now we'll write the API to getTopics from the Appwrite Console.

For your reference

cpp-sdk-appwrite/src/services/Messaging.cpp

Lines 57 to 78 in 4f812f5

	std::string Messaging::getTopic(const std::string &topicId) {
	if (topicId.empty()) {
	throw AppwriteException("Missing required parameter: 'topicId'");
	}
	std::string url = Config::API_BASE_URL + "/messaging/topics/" + topicId;
	std::vector<std::string> headers = Config::getHeaders(projectId);
	headers.push_back("X-Appwrite-Key: " + apiKey);
	std::string response;
	int statusCode = Utils::getRequest(url, headers, response);
	if (statusCode == HttpStatus::OK) {
	return response;
	} else {
	throw AppwriteException(
	"Error fetching topic. Status code: " + std::to_string(statusCode) +
	"\n\nResponse: " + response);
	}
	}

• Now we'd need to test the API that we've created, hence we'll create an example-file.cpp to verify it's working.

For your reference

cpp-sdk-appwrite/examples/messaging/topics/getTopic.cpp

Lines 1 to 19 in 4f812f5

	#include "Appwrite.hpp"
	#include <iostream>
	int main() {
	std::string projectId = "66fbb5a100070a3a1d19";
	std::string apiKey = "";
	Appwrite appwrite(projectId, apiKey);
	std::string topicId = "67b3048600077f40b8a7";
	try {
	std::string response = appwrite.getMessaging().getTopic(topicId);
	std::cout << "Topic Fetched! \nResponse: " << response << std::endl;
	} catch (const AppwriteException& ex) {
	std::cerr << "Exception: " << ex.what() << std::endl;
	}
	return 0;
	}

• Okay, at this point we're all set to test the API, but before that we need to add an entry to the Makefile, to compile and test it.

For your reference

cpp-sdk-appwrite/Makefile

Lines 249 to 252 in 4f812f5

	# Messaging - Topics
	getTopic: $(SRCS) $(EXAMPLES_DIR)/messaging/topics/getTopic.cpp
	@mkdir -p ./$(TESTS_DIR)
	$(CXX) $(CXXFLAGS) -o ./$(TESTS_DIR)/getTopic $(SRCS) $(EXAMPLES_DIR)/messaging/topics/getTopic.cpp $(LDFLAGS)

• Now we'll compile and run our API.

  # Linux
  make getTopic

  # Windows
  mingw32-make getTopic

• This will create the binary for the API in ./tests/ directory.

• Finally we'll run our API and debug it further based on my requirement.

cd tests/
./getTopic

Summary

You’ve now:

• Investigated the API from the docs and SDKs
• Declared and implemented the getTopic API
• Created a test case
• Updated the build pipeline
• Successfully compiled and executed your implementation

🎉 You’ve added a new API to the C++ Appwrite SDK!