氮 - 動態創建活動

Question

我是Erlang /氮的初學者。 我正在通過mnesia數據庫返回投標系統。 在我的索引頁，我有以下代碼和各種物品和它們的屬性從數據庫中獲取動態創建：

%% -*- mode: nitrogen -*- 
-module (index). 
-compile(export_all). 
-include_lib("nitrogen/include/wf.hrl"). 

main() -> #template { file="./site/templates/bare.html" }. 

title() -> "Meir Panim Gala Dinner silent auction". 

body() -> 

    Header = [#panel{id=header, body=[#h1{text="Meir Panim Gala Dinner silent auction"}]}], 

    {atomic, Items} = item_database:get_all(), 
    Elements = lists:map(fun(X) -> 
    {item, Index, Title, _, Picture, _, _, Reserve, CurrentBid} = X,  
    #panel{id=items, body=[ 
        #span{id=title, text=Title}, 
        #image{id=image, image= "images/" ++ Picture}, 
        #span{id=currentbid, text="Current bid: £" ++ integer_to_list(CurrentBid)}, 
        #span{id=reserve, text="Reserve: £" ++ wf:to_list(Reserve)}, 
        #link{id=showalert, text="More info/Place your bid", postback="showalert"++integer_to_list(Index)} 
        ] 
      } 
    end, Items), 
    wf:f([Header, Elements]). 

{atomic, Items} = item_database:get_all(), 
    Actions = lists:map(fun(X) -> 
    {item, Index, _, _, _, _, _, _, _} = X,  
    event("showalert"++integer_to_list(Index)) -> 
     wf:wire(#alert{text="action "++integer_to_list(Index)++" clicked"}) 
    end, Items). 

我試圖以同樣的方式來建立我的事件，但它不工作。 在我的代碼中，警報將替換爲包含接受投標的表單的Lightbox。 請幫助並告訴我我做錯了什麼。

Answer 1

據我所知，你在頁面上用「event」捕獲事件。

，所以我會嘗試這樣的：

postback={bid, Index} 

，並在上下抓住它具有：

event({bid, Index})-> 
%% do stuff 
ok; 
event(_)-> 
ok. 

更新：

這僅僅是如何修復的例子它，它不是最好的方式。

%% -*- mode: nitrogen -*- 
-module (index). 
-compile(export_all). 
-include_lib("nitrogen/include/wf.hrl"). 

main() -> #template { file="./site/templates/bare.html" }. 

title() -> "Meir Panim Gala Dinner silent auction". 

body() -> 

    Header = [#panel{id=header, body=[#h1{text="Meir Panim Gala Dinner silent auction"}]}], 

    {atomic, Items} = item_database:get_all(), 
    Elements = lists:map(fun(X) -> 
    {item, Index, Title, _, Picture, _, _, Reserve, CurrentBid} = X,  
    #panel{id=items, body=[ 
        #span{id=title, text=Title}, 
        #image{id=image, image= "images/" ++ Picture}, 
        #span{id=currentbid, text="Current bid: £" ++ integer_to_list(CurrentBid)}, 
        #span{id=reserve, text="Reserve: £" ++ wf:to_list(Reserve)}, 
        #link{id=showalert, text="More info/Place your bid", postback={bid,Index}} 
        ] 
      } 
    end, Items), 
    wf:f([Header, Elements]). 

event({bid, Idx})-> 
    %% you would better have a function to get one item at a time in item_database 
    case item_database:get_by_index(Idx) of 
    {atomic, X} -> 
     %% This is not the right way, use records 
     {item, Index, Title, _, Picture, _, _, Reserve, CurrentBid} = X, 
     wf:wire(#alert{text="action "++ Title ++" clicked"}); 
    _ -> 
     wf:wire(#alert{text="item not found"}) 
    end; 

event(_)-> 
    ok. 

Answer 2

%% -*- mode: nitrogen -*- 
-module (index). 
-compile(export_all). 
-include_lib("nitrogen/include/wf.hrl"). 

main() -> #template { file="./site/templates/bare.html" }. 

title() -> "Welcome to Nitrogen". 

body() -> 
    {atomic, Records} = item_database:get_all(), 

    Elements = lists:map(fun(X) -> 
                  {item, Index, Title, _, _, _, _, _, _} = X, 
                  #panel{body=[ 
                   #span{text=Title, style="font-size: 20px; font-weight: bold;"}, 
                   #br{}, 
                   #link{text="more info/place your bid", postback="showinfo"++integer_to_list(Index)}, 
                   #br{}, 
                   #link{text="register your bid", postback="registerbid"++integer_to_list(Index)}, 
                   #br{}, 
                   #br{}, 

                   #lightbox{id="lightbox"++integer_to_list(Index), style="display: none;", body=[ 
                         #span{text=Title, style="font-size: 24px; font-weight: bold; color: #ffffff;"} 
                        ]} 
                  ]} 
                end, Records), 

    wf:f([Elements]). 

event(Event) -> 
    case (re:run(Event, "showinfo")) of 
     {match, _} -> 
      [_, _, SI] = re:split(Event, "(showinfo)"), 
      ShowIndex = binary:bin_to_list(SI), 
      wf:wire(#show{target="lightbox"++ShowIndex}); 
     _ -> ok  
    end, 

    case (re:run(Event, "registerbid")) of 
     {match, _} -> 
      [_, _, RI] = re:split(Event, "(registerbid)"), 
      RegisterIndex = binary:bin_to_list(RI), 
      wf:wire(#alert{text="registerbid"++RegisterIndex++" clicked"}); 
     _ -> ok  
    end.