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setTimeout内でjQueryの$(this)を使う場合の注意点

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問題点

setTimeoutは、一定時間後に渡された関数を実行する関数です。
今回、このsetTimeoutに渡した関数内でjQueryの$(this)を使ったらエラーになりました。

Uncaught TypeError: Cannot call method 'toLowerCase' of undefined

解決方法

$.proxyをかませば問題なく動作しました。

javascript
$("#bar").click(function(){
  setTimeout($.proxy(function(){
    $("#foo").load('/foo/bar', {value: $(this).val()});
  }, this), 1000);
});

$.proxyメソッドは、渡された関数内のthisを第二引数にすることができるというものです。

参考URL

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