Marsy

Marsy is a library that allow you to deserialize and manage data returned by SpaceX API. Marsy currently support V4 of API.

• Usage
  • Start
  • Queries
  • Size of binary in debug mode
• Things you should be aware of
  • Asynchronous
  • Internet connection
  • Dates parsing
• Sample code
• External libraries

Usage

Start

To use it just add source files to your project.

You can use functions provided by services or write your own services on top of provided parsers. Remember to look here before start.

Library uses C++17 features. You need to remember it, when you compile your program.

Queries

SpaceX API uses queries to filter data. They're based on mongoose-paginate.

You can build simple query with QueryBuilder or make one on your own based on nlohmann::json documentation.

You can build simple options -> select with SortBuilder or make one on your own based on nlohmann::json documentation.

Currently Marsy doesn't provide query builder for these: options -> select, options -> populate You need to write them based on nlohmann::json documentation.

Field	Type	Docs
query	nlohmann::json	link
options -> select	nlohmann::json	link
options -> sort	nlohmann::json	link
options -> populate	nlohmann::json	link

Size of binary in debug mode

Since Marsy includes JSON in several classes, output program can be huge when compiled in debug mode (I achieved 60MB binaries). Remember to roll it out as release, when you done with testing.

Things you should be aware of

Asynchronous

Currently functions are synchronous. Don't call them from UI thread. Use second thread or features like std::future.

Internet connection

Marsy doesn't handle internet connection, so you need to provide implementation of IConnection interface. Enum ResponseStatus is to help you handle different statuses returned by API. Service will parse returned JSON only when status is ResponseStatus::ok.

There are 2 reasons why I made is as it is:

• C++ doesn't have internet connection in STL yet. I did not want to include big library or use different system APIs to provide support for more than one platform e.g. (WinAPI, POSIX etc.),
• maybe you already have library with internet connection in your project or you want to use one that you like the most.

However I made IConnector implementation based on curl and curlcpp. You can find it here.

Dates parsing

Marsy doesn't parse dates returned by API. They're stored as strings.

Sample code

#include <iostream>
#include <memory>

#include "Connection/Implementation/CurlConnector.h"
#include "Services/Capsules/CapsuleService.h"

using namespace Marsy;

int main()
{
    std::shared_ptr<IConnector> conn = std::make_shared<CurlConnector>();
    CapsuleService capsuleService(conn);
    ServiceResponse<CapsuleModel> capsuleResponse = capsuleService.getCapsule("5e9e2c5bf35918ed873b2664");
    CapsuleModel capsule = capsuleResponse.object;
    std::cout << "serial " << capsule.serial.value() << std::endl;
    std::cout << "reuseCount " << capsule.reuseCount.value() << std::endl;
    std::cout << "waterLandings " << capsule.waterLandings.value() << std::endl;
    std::cout << "landLandings " << capsule.landLandings.value() << std::endl;
    std::cout << "lastUpdate " << capsule.lastUpdate.value() << std::endl;
    for(auto i : capsule.launches.value())
    {
        std::cout << "launches " << i << std::endl;
    }
    std::cout << "id " << capsule.id.value() << std::endl;
}

External libraries

• JSON