http://bfexplorer.net/Articles/Content/431

PlaceBetAtEmptyPrice.fsx

// Bfexplorer cannot be held responsible for any losses or damages incurred during the use of this betfair bot.
// It is up to you to determine the level of risk you wish to trade under. 
// Do not gamble with money you cannot afford to lose.

module BfexplorerBot

(*
//#I @"C:\Program Files (x86)\BeloSoft\Bfexplorer\"
#I @"D:\Projects\Bfexplorer\Development\Applications\BeloSoft.Bfexplorer.App\bin\Debug\"

#r "BeloSoft.Data.dll"
#r "BeloSoft.Bfexplorer.Domain.dll"
#r "BeloSoft.Bfexplorer.Trading.dll"
#r "BeloSoft.Bfexplorer.Service.Core.dll"
*)

open BeloSoft.Bfexplorer.Domain
open BeloSoft.Bfexplorer.Trading

/// <summary>
/// TriggerStatus
/// </summary>
type TriggerStatus =
    | Initialize
    | PlaceBet
    | WaitForResult

/// <summary>
/// PlaceBetAtEmptyPrice
/// </summary>
type PlaceBetAtEmptyPrice(_market : Market, selection : Selection, _botName : string, botTriggerParameters : BotTriggerParameters, _myBfexplorer : IMyBfexplorer) =

    let mutable status = TriggerStatus.Initialize
    let mutable betsPlaced = false

    let getEmptyPrice (betType : BetType) =
        let priceGridData = selection.PriceGridData.DataContext
        let startIndex, nextIndex, findFun =
            if betType = BetType.Back
            then
                priceGridData.BestToLayIndex, -1, (fun (priceData : PriceData) -> priceData.ToLay = 0.0)
            else
                priceGridData.BestToBackIndex, +1, (fun (priceData : PriceData) -> priceData.ToBack = 0.0)

        let mutable doLoop = true
        let mutable index = startIndex
        let mutable price = 0.0

        while doLoop do
            if index > 0 && index < OddsData.NumberOfOdds
            then
                let priceData = priceGridData.GetPriceData(index)

                if findFun priceData
                then
                    price <- priceData.Price
                    doLoop <- false
                else
                    index <- index + nextIndex
            else
                doLoop <- false

        if price = 0.0
        then
            None
        else
            Some price

    let onBetsPlaced (_status : bool) =
        betsPlaced <- true
            
    interface IBotTrigger with

        /// <summary>
        /// Execute
        /// </summary>
        member __.Execute() =
            match status with
            | TriggerStatus.Initialize -> 
            
                status <- TriggerStatus.PlaceBet
                selection.PriceGridDataEnabled <- true

                TriggerResult.WaitingForOperation

            | TriggerStatus.PlaceBet ->
                            
                let betType = defaultArg (botTriggerParameters.GetEnumParameter<BetType>("BetType")) BetType.Back

                match getEmptyPrice betType with
                | Some price ->

                    status <- TriggerStatus.WaitForResult

                    let stake = defaultArg (botTriggerParameters.GetParameter<float>("Stake")) 2.0

                    let bets = [ SelectionBetOrder.Create(selection, betType, price, stake) ]

                    TriggerResult.PlaceBets (bets, PersistenceType.Lapse, onBetsPlaced)

                | None -> TriggerResult.EndExecution

            | TriggerStatus.WaitForResult -> 
            
                if betsPlaced
                then
                    TriggerResult.EndExecution
                else
                    TriggerResult.WaitingForOperation

        /// <summary>
        /// EndExecution
        /// </summary>
        member __.EndExecution() =
            ()