Creating a multi user 4D Agenda To demonstrate the use of 4D Agenda in a multi user environment we will build a simple demonstration 4D app. Nothing fancy, just to give you some directions to go. Let’s start off with the first table for the users Table name: [USERS] Field name      Type    Options UserID          Longint Indexed/unique UserName                Alpha[80] Password                Alpha[80] And an event table Table name: [EVENTS] Field name      Type    Options EventID         Longint Indexed/Unique UserID          Longint Indexed StartDate       Date    Indexed EndDate         Date StartTime       Time    Indexed EndTime         Time    Indexed Description     Text     Now create in the Database startup routine the following code C_LONGINT(<>SYS_USERID) All Records([USERS]) If(Records in selection([USERS])=0)         USER_CreateSomeUsers End if <>SYS_USERID:=USER_Login Now create the method: “USER_CreateSomeUsers” CREATE RECORD([USERS]) [USERS]UserID:=Sequence Number([USERS]) [USERS]UserName:=”Chris” [USERS]Password:=”Smit” SAVE RECORD([USERS]) CREATE RECORD([USERS]) [USERS]UserID:=Sequence Number([USERS]) [USERS]UserName:=”Hans” [USERS]Password:=”Apple” SAVE RECORD([USERS]) UNLOAD RECORD([USERS]) Now let’s build some simple login dialog box in the [USERS] table. I leave the design of the dialog box to your own creativity, it should include two text variables, “vs_Name” and “vs_Password” and an ACCEPT-button. The simple login method, C_LONGINT($Window) C_LONINT($0) $Window:=open window(10;40;310;340;8;””;””) DIALOG([USERS];”LoginDialog”) CLOSE WINDOW If(OK=1)         QUERY([USERS];[USERS]Name=vsName)         $0:=[USERS]UserID Else         $0:=0 End if As I said before nothing fancy, no error checking or password checking stuff, just to get you started in one of the many possibility’s to create a multi-user agenda. Now the 4D Agenda dialog box, this one can best be used from the 4D Agenda demo app. The Form method should look something like this: C_DATE(vDate) C_INTEGER(vStart;vEnd) C_LONGINT(err) Case of         : (Form event= On Load )         vStart:=7         vEnd:=22         vDate:=Current date         err:= AG SET EVENT TABLE NUM (vAgenda ; Table(->[Events]))         err:= AG SET START DATE FIELD NUM (vAgenda ; Field(->[Events]StartDate))         err:= AG SET END DATE FIELD NUM (vAgenda ; Field(->[Events]EndDate))         err:= AG SET START TIME FIELD NUM (vAgenda ; Field(->[Events]StartTime))         err:= AG SET END TIME FIELD NUM (vAgenda ; Field(->[Events]EndTime))         err:= AG SET DESCRIPTION FIELD NUM (vAgenda ; Field(->[Events]Description))         `Set the UserID field         err:= AG SET USERID FIELD NUM (vAgenda ; Field(->[Events]UserID))         err:= AG SET EVENTID FIELD NUM (vAgenda ; Field(->[Events]EventID))         err:= AG SET AGENDA START HOUR (vAgenda ; vStart)         err:= AG SET AGENDA END HOUR (vAgenda ; vEnd)         err:= AG AGENDA EVENT HANDLER (vAgenda ; "AG_EventHandler")         ` Set the current User ID to the ID of the user who has just logged-in         err:= AG CURRENT USER ID (vAgenda ; <>SYS_USERID) End case 4D Agenda will keep track of a single Agenda per user this way. To create an easy way to switch to the Agenda of an other user, create a pop-up menu on the 4D Agenda dialog box with the following method attached to it: If (pop_Users # 0)         vUserID:=arr_UserID{pop_Users}         err:= AG CURRENT USER ID (vAgenda ; vUserID)         ` And to prevent any changes to the Agenda         err:= AG SET EVENT DRAG LOCK (vAgenda ; AG_True)         err:= AG SET EVENT EDIT LOCK (vAgenda ; AG_True) Else `Switch back to the current user         $A:=Find in Array (arr_UserID ; <>SYS_USERID)         pop_Users:=$A         err:= AG CURRENT USER ID (vAgenda ; vUserID)         err:= AG SET EVENT DRAG LOCK (vAgenda ; AG_False)         err:= AG SET EVENT EDIT LOCK (vAgenda ; AG_False) End if err:=AG REDRAW (vAgenda ; AG_Reload)