ditto::DocumentId Struct Reference

An identifier for a Document. More...

#include <DocumentId.hpp>

Public Member Functions
	DocumentId (nlohmann::json id_value)
	Creates a new DocumentId.
bool	operator== (const DocumentId &rhs) const
bool	operator!= (const DocumentId &rhs) const
DocumentIdPath	operator[] (std::string key) const
	Used to specify a path to a key in the document ID that you can subscript further to access a nested key in the document ID.
DocumentIdPath	operator[] (std::size_t index) const
	Used to specify an index in the array at the preceding key-path specified through the subscripting defined previously. You can subscript the return value further to access a further nested key in the document ID.
bool	empty () const
	Returns whether or not the document ID is empty (and therefore invalid).
nlohmann::json	value () const
	Get the underlying value of the document identifier as a native type.
std::string	to_string () const
	Returns a stringified representation of a document identifier.

Detailed Description

An identifier for a Document.

Each DocumentId represents a unique identifier for a document.

Constructor & Destructor Documentation

DocumentId()

ditto::DocumentId::DocumentId ( nlohmann::json  id_value )

explicit

Creates a new DocumentId.

A document ID can be created from any of the following:

• string
• integer
• boolean
• null
• byte array
• array (containing any of the items in this list)
• map (where the keys must be strings and the values can be made up of any of the items in this list)

Note that you cannot use floats or other custom types to create a document ID.

Document IDs are also limited in size, based on their serialized representation, to 256 bytes. You will receive an error if you try to create a document ID that exceeds the size limit.

Parameters

[in]

value

the value that represents the document identifier.

Returns

a DocumentId that uniquely identifies a Document.

Member Function Documentation

empty()

bool ditto::DocumentId::empty

(

)

const

Returns whether or not the document ID is empty (and therefore invalid).

Returns

a bool representing whether or not the document ID is empty (and therefore invalid).

operator[]() [1/2]

DocumentIdPath ditto::DocumentId::operator[]

(

std::size_t

index

)

const

Used to specify an index in the array at the preceding key-path specified through the subscripting defined previously. You can subscript the return value further to access a further nested key in the document ID.

Parameters

[in]

index

the index of the array that you wish to access in the key previously specified with the preceding subscripting.

operator[]() [2/2]

DocumentIdPath ditto::DocumentId::operator[]

(

std::string

key

)

const

Used to specify a path to a key in the document ID that you can subscript further to access a nested key in the document ID.

Parameters

[in]

key

the next part of the path needed to get to the key in the document ID you wish to get the value of.

to_string()

std::string ditto::DocumentId::to_string

(

)

const

Returns a stringified representation of a document identifier.

The returned string can be used directly in queries that you use with other Ditto functions. For example you could create a query that was like this:

my_collection.find("_id == " + doc_id.to_string())

Returns

a stringified representation of the document identifier.

value()

json ditto::DocumentId::value

(

)

const

Get the underlying value of the document identifier as a native type.

Returns

the underlying value of the document identifier as a native type.