# Views on offers ## Public getters ### `best(address outbound, address inbound)` {% hint style="info" %} Returns the offer identifier that occupies the best [rank](/mangrove-core/technical-references/taking-and-making-offers/market.md#offer-rank) in the `(outbound, inbound)`[offer list](/mangrove-core/technical-references/taking-and-making-offers/market.md). * highest outbound volume * least gas required * oldest time of insertion on the list {% endhint %} {% tabs %} {% tab title="Solidity" %} {% code title="bestOffer.sol" %} ```solidity import "src/IMangrove.sol"; // context of the call IMangrove mgv; address outbound_tkn; address inbound_tkn; uint best = mgv.best(outbound_tkn, inbound_tkn); ``` {% endcode %} {% endtab %} {% tab title="ethers.js" %} {% code title="bestOffer.js" %} ```javascript const { ethers } = require("ethers"); // context let outboundTkn; // address of outbound token ERC20 let inboundTkn; // address of inbound token ERC20 let MGV_address; let MGV_abi; // Mangrove contract's abi const mgv = new ethers.Contract( MGV_address, MGV_abi, ethers.provider ); // getting best offer of the (outTkn,inbTk) market const best = await mgv.best(outboundTkn, inboundTkn); ``` {% endcode %} {% endtab %} {% endtabs %} ### `offers(address, address) / offerDetails(address, address, uint)` {% hint style="info" %} The data pertaining to a particular offer is contained in the `OfferUnpacked` and `OfferDetailUnpacked` structs, which are stored as packed custom types called, respectively, `OfferPacked` and `OfferDetailUnpacked.` For on-chain calls, Mangrove provides unpacking functions to extract a particular field out of a packed structure. For off-chain calls, Mangrove also provide direct getter for the unpacked structures. {% endhint %} {% tabs %} {% tab title="Solidity" %} {% code title="getOfferData.sol" %} ```solidity import "src/IMangrove.sol"; import {MgvStructs} "src/MgvLib.sol"; // context of the call address MGV; address outTkn; address inbTkn; uint offerId; // the id of the offer one wishes to get the data of // if one wishes to get the totally unpacked data (gas costly!): (MgvStructs.OfferUnpacked memory offer, MgvStructs.OfferDetailUnpacked memory offerDetail) = Mangrove(MGV) .offerInfo(outTkn,inbTkn,offerId); // if one wishes to access a few particular fields, say `wants`, `gives` and `gasreq` parameters of the offer: // 1. getting packed (outTkn, inbTkn) Offer List data MgvStructs.OfferPacked memory offer32 = Mangrove(MGV) .offers(outTkn, inbTkn, offerId); MgvStructs.OfferDetailPacked memory offerDetail32 = Mangrove(MGV) .offerDetails(outTkn, inbTkn, offerId); // for all fields f of OfferUnpacked // offer.f == offer32.f() // for all fields f of OfferDetailUnpacked // offerDetail.f == offerDetail32.f() ``` {% endcode %} {% endtab %} {% tab title="ethers.js" %} {% code title="getOfferData.js" %} ```javascript const { ethers } = require("ethers"); // context let outTkn; // address of outbound token ERC20 let inbTkn; // address of inbound token ERC20 let MGV_address; // address of Mangrove let MGV_abi; // Mangrove contract's abi const Mangrove = new ethers.Contract( MGV_address, MGV_abi, ethers.provider ); // getting offer data in an abi compatible format const [offer, offerDetail] = await Mangrove.offerInfo(outTkn,inbTkn,offerId); // now one can access any field, say wants, gives and gasprice of the offer: const wants = offer.wants; const gives = offer.gives; const gasreq = offerDetail.gasreq; ``` {% endcode %} {% endtab %} {% endtabs %} ### `isLive(address, address, uint)` {% hint style="info" %} An offer is **live** in a given [Offer Lists](/mangrove-core/technical-references/taking-and-making-offers/market.md) if it can be matched during a [market order](/mangrove-core/technical-references/taking-and-making-offers/taker-order.md). One can verify whether `offerId` identifies a **live** offer in a (`outboundToken`,`inboundToken`) Offer List of Mangrove using this view function. {% endhint %} {% tabs %} {% tab title="Solidity" %} {% code title="isLive.sol" %} ```solidity import "src/IMangrove.sol"; // context of the call IMangrove mgv; address outTkn; address inbTkn; address offerId; // checking whether offerId is live in the (outTkn, inbTkn) order book. bool isLive = mgv.isLive(outTkn,inbTkn,offerId); ``` {% endcode %} {% endtab %} {% tab title="ethers.js" %} {% code title="isLive.js" %} ```javascript const { ethers } = require("ethers"); // context let outTkn; // address of outbound token ERC20 let inbTkn; // address of inbound token ERC20 let offerId; // offer id let MGV_address; // address of Mangrove let MGV_abi; // Mangrove contract's abi const Mangrove = new ethers.Contract( MGV_address, MGV_abi, ethers.provider ); // checking whether offerId is live on (outTkn, inbTkn) Offer List. const isLive = await Mangrove.isLive(outTkn,outTkn,offerId); ``` {% endcode %} {% endtab %} {% endtabs %} ## Custom types {% hint style="info" %} Offer data is split between `OfferUnpacked` and `OfferDetailedUnPacked` for storage read/write optimisation (as both structs can be efficiently packed on storage). {% endhint %} ### `MgvLib.MgvStructs.OfferUnpacked` | Type | Field | Comments | | -------- | ------- | -------------------------------------------------------------------------- | | `uint32` | `prev` | Predecessor offer id (better price) | | `uint32` | `next` | Successor offer id (worst price) | | `uint96` | `gives` | What the offer gives (in *wei* units of base token of the offer's market) | | `uint96` | `wants` | What the offer wants (in *wei* units of quote token of the offer's market) | ### `MgvLib.OfferDetailUnpacked` | Type | Field | Comments | | --------- | --------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `address` | `maker` | address of the offer's [Maker Contract](/mangrove-core/technical-references/taking-and-making-offers/reactive-offer/maker-contract.md) | | `uint24` | `gasreq` | Gas required by the offer (in gas units) | | `uint16` | `gasprice` | The gas price covered by the offer bounty (in *gwei* per gas units) | | `uint24` | `offer_gasbase` | Mangrove's [gasbase](/mangrove-core/technical-references/governance-parameters/mangrove-configuration.md#local-parameters) at the time the offer was posted (in gas units) | ## --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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