Implement player attribute backend (#4155)

* This backend permit mods to store extra players attributes to a common interface.
* Add the obj:set_attribute(attr, value) Lua call
* Add the obj:get_attribute(attr) Lua call

Examples:
* player:set_attribute("home:home", "10,25,-78")
* player:get_attribute("default:mana")

Attributes are saved as a json in the player file in extended_attributes
key

They are saved only if a modification on the attributes occurs and loaded
when emergePlayer is called (they are attached to PlayerSAO).

1 files changed, 37 insertions, 0 deletions

diff --git a/src/content_sao.h b/src/content_sao.h
index c3674fa2d..bbf244742 100644
--- a/src/content_sao.h
+++ b/src/content_sao.h
@@ -180,6 +180,7 @@ public:
 	}
 };
 
+typedef UNORDERED_MAP<std::string, std::string> PlayerAttributes;
 class RemotePlayer;
 
 class PlayerSAO : public UnitSAO
@@ -250,6 +251,39 @@ public:
 	void setWieldIndex(int i);
 
 	/*
+		Modding interface
+	*/
+	inline void setExtendedAttribute(const std::string &attr, const std::string &value)
+	{
+		m_extra_attributes[attr] = value;
+		m_extended_attributes_modified = true;
+	}
+
+	inline bool getExtendedAttribute(const std::string &attr, std::string *value)
+	{
+		if (m_extra_attributes.find(attr) == m_extra_attributes.end())
+			return false;
+
+		*value = m_extra_attributes[attr];
+		return true;
+	}
+
+	inline const PlayerAttributes &getExtendedAttributes()
+	{
+		return m_extra_attributes;
+	}
+
+	inline bool extendedAttributesModified() const
+	{
+		return m_extended_attributes_modified;
+	}
+
+	inline void setExtendedAttributeModified(bool v)
+	{
+		m_extended_attributes_modified = v;
+	}
+
+	/*
 		PlayerSAO-specific
 	*/
 
@@ -343,6 +377,9 @@ private:
 	f32 m_pitch;
 	f32 m_fov;
 	s16 m_wanted_range;
+
+	PlayerAttributes m_extra_attributes;
+	bool m_extended_attributes_modified;
 public:
 	float m_physics_override_speed;
 	float m_physics_override_jump;