2

我有一个 Google Apps 脚本，它可以动态生成按钮并为每个 ClickHandler 分配一个 ClickHandler，然后再调用一个函数。我的问题是，因为每个按钮都调用相同的函数，所以我无法找到一种方法来识别它们中的哪一个实际进行了调用。这是一个代码示例：

var handler = app.createServerHandler("buttonAction");
for (i=1,...) {
  app.createButton(...).setId(i).addClickHandler(handler);
}
function buttonAction() {
  //How do I know what button made the call?
}
4

3 回答 3

5

另一种选择是使用 e.parameter.source 值来确定触发 serverHandler 被调用的元素的 ID。

这是一个例子：

function doGet(e) {
  var app = UiApp.createApplication();
  var handler = app.createServerHandler("buttonAction");

  for (var i = 0; i < 4; i++) {
    app.add(app.createButton('button'+i).setId(i).addClickHandler(handler));
  }
  return app;
}


function buttonAction(e) {
  var app = UiApp.getActiveApplication();
  Logger.log(e.parameter.source);    
}

e.parameter.source 将包含元素的 ID，然后您可以使用它来调用 app.getElementById(e.parameter.source) ...

于 2012-04-11T19:28:58.970 回答
0

我有同样的问题。它使用标签工作。

例如

设置

var button = addButton(app
                    ,panel
                    ,"buttonActiveTrelloProjects_" + i.toString()
                    ,appVars.buttonWidth() + "px"
                    ,appVars.level2ButtonHeight().toString() + "px"
                    ,false
                    ,false
                    ,"Trello"
                    ,"buttonActiveTrelloProjectsHandler"
                       ,(appVars.buttonLhsGap() * buttonCntr) + (appVars.buttonWidth() * (buttonCntr - 1 )   + 9)
                    ,(appVars.level2ButtonTopGap() * 34) 
                    ,3
                    ,"button");
      button.setTag(projectName );

利用

function buttonActiveProjectsChartHandler_1(button){

...

buttonTag        = getButtonTag(button);
chartType        = buttonTag.split(";")[1];
activeProject    = buttonTag.split(";")[0]; 

...



}

function getButtonTag(button){
var jsonButton = JSON.stringify(button);
  var source = button.parameter.source;
  var tagPtr = source + "_tag";
  return button.parameter[tagPtr];
}
于 2014-01-22T14:07:50.503 回答
0

You could create multiple handlers, each for one button:

for (i=1,...) {
  var handler = app.createServerHandler("buttonAction" + i);
  app.createButton(...).setId(i).addClickHandler(handler);
}

function buttonAction1() {
  // code to handle button 1
}

function buttonAction2() {
  // code to handle button 2
}

function buttonAction...

I wouldn't recommend of having these sort of "anonymous" action handlers though, as you might be having troubles later in remembering which actionX does what.

(e.g. have a different approach, w/o a loop, or prepare a dictionary-like/array object of meaningful handler names before that loop.)

OTOH, you could use event object argument provided to your callback function:

function buttonAction(event) {
  // use event object here to identify where this event came from
}

The thing is the above event object properties depends on where your callback is being called from. For instance, if it were a submit button where you had a Form, then you could access parameters submitted by that from like so: event.parameter.myParamName. See code sample here.

So, if you have a variable number of buttons, you could use a hidden element + the button:

for (i=1,...) {
  var hiddenAction = app.createHidden("action", "action"+i);

  var handler = app.createServerHandler("buttonAction");
  handler.addCallbackElement(hiddenAction);

  var btn = app.createButton("Button text", handler);

  // you'll need to add both btn and hidden field
  // to the UI
  app.add(hiddenAction);
  app.add(btn);
}

Then, your buttonAction might look like this:

function buttonAction(e) {
  var action = e.parameter.action;
  // do something based on action value here
  // which will be one of "action1", "action2", ...
}

The above is a copy & paste from Hidden class sample.

The above might not work out of the box, but you get the idea: create a hidden element that holds the info you need in your callback, and attach that hidden to your server handler. You could even create multiple hidden elements or a Form panel.

于 2012-04-11T12:26:50.847 回答