asp.net mvc - Handling concurrency exceptions with external API calls -

-

i have following post edit action method, perform 2 update actions:-

  1. edit object on external system suing api calls.

  2. edit object on our system database.

    [httppost] public actionresult create(rackjoin rj, formcollection formvalues) {string controllername = routedata.values["controller"].tostring(); if (modelstate.isvalid) {  var message = "";                 var status = "";                 long assetid = new long();                 xmldocument doc = new xmldocument();                 using (var client = new webclient())                 {                     var query = httputility.parsequerystring(string.empty);                     foreach (string key in formvalues)                     {                         query[key] = this.request.form[key];                     }  query["username"] =  system.web.configuration.webconfigurationmanager.appsettings["apiusername"]; query["password"] =  system.web.configuration.webconfigurationmanager.appsettings["apipassword"]; string apiurl = system.web.configuration.webconfigurationmanager.appsettings["apiurl"]; var url = new uribuilder(apiurl); url.query = query.tostring(); try { string xml = client.downloadstring(url.tostring());                          doc.loadxml(xml);  status = doc.selectsinglenode("/operation/operationstatus").innertext;                         message = doc.selectsinglenode("/operation/message").innertext; }                     catch (webexception ex)                     {                         modelstate.addmodelerror(string.empty, "error occurred:" + ex.innerexception);                     }                 }                  if (status.toupper() == "success")             {                 repository.insertorupdaterack(rj.rack, user.identity.name, rj.resource.resourceid);                 repository.save();                 return redirecttoaction("index");             }             else             {                 modelstate.addmodelerror(string.empty, message.tostring());              }         }     }     catch (dbupdateconcurrencyexception ex)     {

as shown in above code not repository.save() update object on our system, unless api return “success”. facing following problem:- if api return “success” concurrency exception occurred, api update object on external system, object not updated on our system? there way handle situation?

there's no easy way solve situation. 1 way handle ask designers of external api expose method allowing commit transaction done in previous call. first call make modifications external system boolean flag indicating changes still pending. update system , in case of success call external api flag data pending valid.

if have no control on external api , makes changes data first call irreversible, afraid not have choices left. might remember state of object modifying on external system before calling api , in case of exception on system, revert previous state calling api previous values.


Comments

Post a Comment

Popular posts from this blog

plot - Remove Objects from Legend When You Have Also Used Fit, Matlab -

-
Image
i've plotted data points , fitted exponential curve between them using 'fit' in matlab. problem fit-function got fitted line wanted plot, markers on top of regular markers. solved problem plotting wanted markers on top of unwanted couldn't seen. problem. when want show legends dots in there. how can remove markers legend without removing fitted line since both of them hidden inside fit-function? can stop 'fit' plotting unwanted markers? so, want remove blue dot called 'hoff' in picture below. you can leave out legend-entries manually leaving out handles of lines, dont want in legend. try this: %if plot something, want showing in legend, save handle: h_line = plot(x,y) %you dont want show line? dont anything, plot it: plot(mymarker) %then set legend-> can add text legend-entries %a cell-array containing strings want show up: legend([h_line another_line],{'text1' 'text2'}) with example (see comments) came solution:
Read more

java - Why does my date parsing return a weird date? -

-
here code using: string string = "08/07/2013".replace('/', '-'); date date = new simpledateformat("yyyy-mm-dd").parse(string); why date return: "wen jan 3 00:00:00 est 14"? not @ date format told use. edit: need format because database using requires format. the format use parse date string, not match it. using yyyy 08 . use following format: new simpledateformat("dd-mm-yyyy") and why @ replacing / - ? can build pattern original string only: string string = "08/07/2013" date date = new simpledateformat("dd/mm/yyyy").parse(string); and if want date string in yyyy-mm-dd format, can format date using dateformat#format(date) method: string formatteddate = new simpledateformat("yyyy-mm-dd").format(date); see also: change date format in java string simpledateformat java doc
Read more

Need help in packaging app using TideSDK on Windows -

-
i developed application using tidesdk on windows , when click launchapp works fine. moved package , installed imagemagick , wix 3.0 required packaging on windows. clicked on package runtime , cannot guess packaged app is? found file 'installer' in workspace when click on it says installer not find application path . think application not being packaged properly. here log see in tidesdk: preparing package desktop app runtime. 1 moment... staging trial -> copying contents d:\lab\tidesdk\trial d:\lab\tidesdk\trial\packages\win32\bundle\trial -> copying installer c:\programdata\tidesdk\sdk\win32\1.3.1-beta\installer d:\lab\tidesdk\trial\packages\win32\bundle\trial -> copying runtime d:\lab\tidesdk\trial\packages\win32\bundle\trial -> date: d:\lab\tidesdk\trial\packages\win32\bundle\trial\modules\app\1.3.1-beta -> date: d:\lab\tidesdk\trial\packages\win32\bundle\trial\modules\codec\1.3.1-beta -> date: d:\lab\tidesdk\trial\packages\win32\bundle\trial\mod
Read more