Offer

[Source]

The Offer ledger entry describes an Offer to exchange currencies in Xahau’s decentralized exchange. (In finance, this is more traditionally known as an order.) An [OfferCreate transaction][] only creates an Offer entry in the ledger when the Offer cannot be fully executed immediately by consuming other Offers already in the ledger.

An Offer can become unfunded through other activities in the network while remaining in the ledger. When processing transactions, the network automatically prunes any unfunded Offers that those transactions come across. (Otherwise, unfunded Offers remain because only transactions can change the ledger state.)

Example JSON

{
    "Account": "rBqb89MRQJnMPq8wTwEbtz4kvxrEDfcYvt",
    "BookDirectory": "ACC27DE91DBA86FC509069EAF4BC511D73128B780F2E54BF5E07A369E2446000",
    "BookNode": "0000000000000000",
    "Flags": 131072,
    "LedgerEntryType": "Offer",
    "OwnerNode": "0000000000000000",
    "PreviousTxnID": "F0AB71E777B2DA54B86231E19B82554EF1F8211F92ECA473121C655BFC5329BF",
    "PreviousTxnLgrSeq": 14524914,
    "Sequence": 866,
    "TakerGets": {
        "currency": "XAG",
        "issuer": "r9Dr5xwkeLegBeXq6ujinjSBLQzQ1zQGjH",
        "value": "37"
    },
    "TakerPays": "79550000000",
    "index": "96F76F27D8A327FC48753167EC04A46AA0E382E6F57F32FD12274144D00F1797"
}

Fields

An Offer object has the following fields:

Name	JSON Type	[Internal Type][]	Required?	Description
Account	String	AccountID	Yes	The address of the account that owns this Offer.
BookDirectory	String	Hash256	Yes	The ID of the Offer Directory that links to this Offer.
BookNode	String	UInt64	Yes	A hint indicating which page of the offer directory links to this object, in case the directory consists of multiple pages.
Expiration	Number	UInt32	No	Indicates the time after which this Offer is considered unfunded. See [Specifying Time][] for details.
Flags	Number	UInt32	Yes	A bit-map of boolean flags enabled for this offer.
LedgerEntryType	String	UInt16	Yes	The value 0x006F, mapped to the string Offer, indicates that this object describes an Offer.
OwnerNode	String	UInt64	Yes	A hint indicating which page of the owner directory links to this object, in case the directory consists of multiple pages. Note: The offer does not contain a direct link to the owner directory containing it, since that value can be derived from the Account.
PreviousTxnID	String	Hash256	Yes	The identifying hash of the transaction that most recently modified this object.
PreviousTxnLgrSeq	Number	UInt32	Yes	The [index of the ledger][Ledger Index] that contains the transaction that most recently modified this object.
Sequence	Number	UInt32	Yes	The Sequence value of the [OfferCreate][] transaction that created this Offer object. Used in combination with the Account to identify this Offer.
TakerPays	String or Object	Amount	Yes	The remaining amount and type of currency requested by the Offer creator.
TakerGets	String or Object	Amount	Yes	The remaining amount and type of currency being provided by the Offer creator.

Offer Flags

There are several options that can be either enabled or disabled when an [OfferCreate transaction][] creates an offer object. In the ledger, flags are represented as binary values that can be combined with bitwise-or operations. The bit values for the flags in the ledger are different than the values used to enable or disable those flags in a transaction. Ledger flags have names that begin with lsf.

Offer objects can have the following flag values:

Flag Name	Hex Value	Decimal Value	Corresponding OfferCreate Flag	Description
lsfPassive	0x00010000	65536	tfPassive	The object was placed as a passive Offer. This has no effect on the object in the ledger.
lsfSell	0x00020000	131072	tfSell	The object was placed as a sell Offer. This has no effect on the object in the ledger (because tfSell only matters if you get a better rate than you asked for, which cannot happen after the object enters the ledger).

Offer ID Format

The ID of an Offer object is the [SHA-512Half][] of the following values, concatenated in order:

• The Offer space key (0x006F)

• The AccountID of the account placing the Offer

• The Sequence number of the [OfferCreate transaction][] that created the Offer.

  If the OfferCreate transaction used a Ticket, use the TicketSequence value instead.