Mastodon::Easy::Entity Class Reference

Base class for all entities. More...

#include <easy.hpp>

Inheritance diagram for Mastodon::Easy::Entity:

Public Member Functions
	Entity (const string &json)
	Constructs an Entity object from a JSON string. More...
	Entity ()
	Constructs an empty Entity object. More...
const void	from_string (const string &json)
	Replaces the Entity with a new one from a JSON string. More...
const Json::Value	to_object () const
	Returns the JSON object of the Entity. More...
virtual const bool	valid () const =0
	Returns true if the Entity holds valid data. More...
const string	error () const
	Returns error string sent by the server. More...
const bool	was_set () const
	Returns true if the last requested value was set, false if it was unset. More...

Protected Member Functions
const Json::Value	get (const string &key) const
	Returns the value of key as Json::Value. More...
const string	get_string (const string &key) const
	Returns the value of key as std::string. More...
const uint_fast64_t	get_uint64 (const string &key) const
	Returns the value of key as std::uint_fast64_t. More...
const double	get_double (const string &key) const
	Returns the value of key as double. More...
const bool	get_bool (const string &key) const
	Returns the value of key as bool. More...
const system_clock::time_point	get_time_point (const string &key) const
	Returns the value of key as time_point. More...
const std::vector< string >	get_vector (const string &key) const
	Returns the value of key as vector. More...
const void	set (const string &key, const Json::Value &value)
	Sets the value of key. More...
const std::uint_fast64_t	stouint64 (const string &str) const
const bool	check_valid (const std::vector< string > &attributes) const
	Checks if an Entity is valid. More...

Detailed Description

Base class for all entities.

Since

before 0.11.0

Constructor & Destructor Documentation

Entity() [1/2]

Easy::Entity::Entity ( const string &  json )

explicit

Constructs an Entity object from a JSON string.

Parameters

json	JSON string

Since

before 0.11.0

: _tree(Json::nullValue)
,_was_set(false)
{
    from_string(json);
}

Entity() [2/2]

Easy::Entity::Entity

(

)

Constructs an empty Entity object.

Since

before 0.11.0

: _was_set(false)
{}

Member Function Documentation

check_valid()

const bool Easy::Entity::check_valid ( const std::vector< string > &  attributes ) const

protected

Checks if an Entity is valid.

Parameters

attributes

The attributes to check

Returns

true if all attributes are set

Since

0.18.2

{
    for (const string &attribute: attributes)
    {
        get(attribute);
        if (!was_set())
        {
            return false;
        }
    }

    return true;
}

error()

const string Easy::Entity::error

(

)

const

Returns error string sent by the server.

Since

before 0.11.0

{
    return get_string("error");
}

from_string()

const void Easy::Entity::from_string

(

const string &

json

)

Replaces the Entity with a new one from a JSON string.

Parameters

json	JSON string

Since

before 0.11.0

{
    std::stringstream ss(json);
    ss >> _tree;

    // If the JSON is a single object encapsulated in an array,
    // transform it into an object. If the JSON string is [], transform to null
    if (_tree.type() == Json::ValueType::arrayValue && _tree.size() <= 1)
    {
        _tree = _tree[0];
    }

    if (_tree.isNull())
    {
        ttdebug << "ERROR: JSON string holds no object\n";
        ttdebug << "String was: " << json << '\n';
    }
    else if (!_tree["error"].isNull())
    {
        ttdebug << "ERROR: Server returned an error\n";
        ttdebug << "String was: " << json << '\n';
    }
}

get()

const Json::Value Easy::Entity::get ( const string &  key ) const

protected

Returns the value of key as Json::Value.

Returns an empty object if the value does not exist or is null.

{
    const Json::Value *node;
    if (key.find('.') == std::string::npos)
    {
        node = &_tree[key];
    }
    else
    {
        // If dots in key, we have to walk through the tree
        std::size_t pos = 0;
        string current_key = key;
        node = &_tree;
        while ((pos = current_key.find('.')) != std::string::npos)
        {
            try
            {
                node = &(*node)[current_key.substr(0, pos)];
                current_key = current_key.substr(pos + 1);
            }
            catch (const Json::LogicError &e)
            {
                ttdebug << e.what() << '\n';
                goto error;
            }
        }
        node = &(*node)[current_key];
    }

    if (!node->isNull())
    {
        _was_set = true;
        return *node;
    }

    error:
    ttdebug << "Could not get data: " << key << '\n';
    _was_set = false;
    return Json::Value();
}

get_bool()

const bool Easy::Entity::get_bool ( const string &  key ) const

protected

Returns the value of key as bool.

Returns false if the value does not exist or is null.

{
    const Json::Value node = get(key);

    if (node.isBool())
    {
        _was_set = true;
        return node.asBool();
    }

    _was_set = false;
    return false;
}

get_double()

const double Easy::Entity::get_double ( const string &  key ) const

protected

Returns the value of key as double.

Returns 0.0 if the value does not exist or is null.

{
    const Json::Value node = get(key);

    if (node.isDouble())
    {
        _was_set = true;
        return node.asDouble();
    }

    _was_set = false;
    return 0.0;
}

get_string()

const string Easy::Entity::get_string ( const string &  key ) const

protected

Returns the value of key as std::string.

returns "" if the value does not exist or is null.

{
    const Json::Value node = get(key);

    if (node.isString())
    {
        _was_set = true;
        return node.asString();
    }

    _was_set = false;
    return "";
}

get_time_point()

const system_clock::time_point Easy::Entity::get_time_point ( const string &  key ) const

protected

Returns the value of key as time_point.

Returns clocks epoch if the value does not exist or is null.

{
    const Json::Value node = get(key);

    if (node.isString())
    {
        std::stringstream sstime(node.asString());
        struct std::tm tm = {0};
        sstime >> std::get_time(&tm, "%Y-%m-%dT%T");
        std::time_t time = timegm(&tm);
        _was_set = true;
        return system_clock::from_time_t(time);
    }

    _was_set = false;
    // Return clocks epoch
    return system_clock::time_point();
}

get_uint64()

const uint_fast64_t Easy::Entity::get_uint64 ( const string &  key ) const

protected

Returns the value of key as std::uint_fast64_t.

Returns 0 if the value does not exist or is null.

{
    const Json::Value node = get(key);

    if (node.isUInt64())
    {
        _was_set = true;
        return node.asUInt64();
    }

    _was_set = false;
    return 0;
}

get_vector()

const std::vector< string > Easy::Entity::get_vector ( const string &  key ) const

protected

Returns the value of key as vector.

Returns an empty vector if the value does not exist or is null.

{
    const Json::Value node = get(key);

    if (node.isArray())
    {
        std::vector<string> vec;
        for (const Json::Value &value : node)
        {
            vec.push_back(value.asString());
        }
        _was_set = true;
        return vec;
    }

    _was_set = false;
    return {};
}

set()

const void Easy::Entity::set ( const string &  key, const Json::Value &  value  )

protected

Sets the value of key.

Since

0.17.0

{
    if (key.find('.') == std::string::npos)
    {
        _tree[key] = value;
        return;
    }
    else
    {
        std::size_t pos = 0;
        string current_key = key;
        Json::Value *node = &_tree;

        while ((pos = current_key.find('.')) != std::string::npos)
        {
            try
            {
                node = &(*node)[current_key.substr(0, pos)];
                if (node->isNull())
                {
                    *node = Json::Value(Json::objectValue);
                }
                current_key = current_key.substr(pos + 1);
            }
            catch (const Json::LogicError &e)
            {
                ttdebug << e.what() << '\n';
                goto error;
            }
        }
        (*node)[current_key] = value;
        return;
    }

    error:
    ttdebug << "Could not set data: " << key << '\n';
}

to_object()

const Json::Value Easy::Entity::to_object

(

)

const

Returns the JSON object of the Entity.

Returns

JSON object

Since

before 0.11.0

{
    return _tree;
}

valid()

virtual const bool Mastodon::Easy::Entity::valid ( ) const

pure virtual

Returns true if the Entity holds valid data.

Since

before 0.11.0 (virtual since 0.18.2)

Implemented in Mastodon::Easy::Account::Source, Mastodon::Easy::Tag, Mastodon::Easy::Status, Mastodon::Easy::Account, Mastodon::Easy::Tag::History, Mastodon::Easy::Notification, Mastodon::Easy::Results, Mastodon::Easy::Attachment, Mastodon::Easy::Context, Mastodon::Easy::Instance, Mastodon::Easy::List, Mastodon::Easy::Mention, Mastodon::Easy::PushSubscription, Mastodon::Easy::Card, Mastodon::Easy::Relationship, Mastodon::Easy::Report, Mastodon::Easy::Application, and Mastodon::Easy::Emoji.

was_set()

const bool Easy::Entity::was_set

(

)

const

Returns true if the last requested value was set, false if it was unset.

Members of Easy::Entity-derived classes return a default value depending on its type when the requested value is not found in the JSON. "" for strings, false for bools and so on. Most of the time this is no problem, but sometimes you need to know for sure.

Example:

Easy::Account a(jsonstring);
if (a.note().empty())
{
    if (a.was_set())
    {
        cout << "Account has an empty description.\n";
    }
    else
    {
        cout << "Account has no description.\n";
    }
}

Since

before 0.11.0

{
    return _was_set;
}

---

The documentation for this class was generated from the following files:

• src/easy/easy.hpp
• src/easy/entity.cpp