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Reset

A reset button on an HTML form. A reset button resets all elements in a form to their defaults.

客户端对象
实现版本Navigator 2.0
Navigator 3.0: 添加了 type 属性; 添加了 onBlur and onFocus event handlers; 添加了 blur and focus 方法s
Navigator 4.0: 添加了 handleEvent 方法。

创建源

The HTML INPUT tag, with "reset" as the value of the TYPE attribute. For a given form, the JavaScript runtime engine creates an appropriate Reset object and puts it in the elements array of the corresponding Form object. You access a Reset object by indexing this array. You can index the array either by number or, if supplied, by using the value of the NAME attribute.

事件句柄

描述

A Reset object on a form looks as follows:

A Reset object is a form element and must be defined within a FORM tag.

The reset button's onClick event handler cannot prevent a form from being reset; once the button is clicked, the reset cannot be canceled.

属性概览

formSpecifies the form containing the Reset object.
nameReflects the NAME attribute.
typeReflects the TYPE attribute.
valueReflects the VALUE attribute.

方法概览

blurRemoves focus from the reset button.
clickSimulates a mouse-click on the reset button.
focusGives focus to the reset button.
handleEvent调用指定事件的控制句柄。

示例

示例 1. The following example displays a Text object with the default value "CA" and a reset button with the text "Clear Form" displayed on its face. If the user types a state abbreviation in the Text object and then clicks the Clear Form button, the original value of "CA" is restored.

<B>State: </B><INPUT TYPE="text" NAME="state" VALUE="CA" SIZE="2">
<P><INPUT TYPE="reset" VALUE="Clear Form">
示例 2. The following example displays two Text objects, a Select object, and three radio buttons; all of these objects have default values. The form also has a reset button with the text "Defaults" on its face. If the user changes the value of any of the objects and then clicks the Defaults button, the original values are restored.

<HTML>
<HEAD>
<TITLE>Reset object example</TITLE>
</HEAD>
<BODY>
<FORM NAME="form1">
<BR><B>City: </B><INPUT TYPE="text" NAME="city" VALUE="Santa Cruz" SIZE="20">
<B>State: </B><INPUT TYPE="text" NAME="state" VALUE="CA" SIZE="2">
<P><SELECT NAME="colorChoice">
   <OPTION SELECTED> Blue
   <OPTION> Yellow
   <OPTION> Green
   <OPTION> Red
</SELECT>
<P><INPUT TYPE="radio" NAME="musicChoice" VALUE="soul-and-r&b"
   CHECKED> Soul and R&B
<BR><INPUT TYPE="radio" NAME="musicChoice" VALUE="jazz">
   Jazz
<BR><INPUT TYPE="radio" NAME="musicChoice" VALUE="classical">
   Classical
<P><INPUT TYPE="reset" VALUE="Defaults" NAME="reset1">
</FORM>
</BODY>
</HTML>

参看

Button, Form, onReset, Form.reset, Submit

属性

form

An object reference specifying the form containing the reset button.

属性源Reset
只读
实现版本Navigator 2.0

描述

每个表单元素都有一个 form 属性用于指向元素的父表单。该属性在事件控制句柄中特别有用,你可能想要由其获得当前表单中其它元素。

参看

Form

name

A string specifying the name of the reset button.

属性源Reset
实现版本Navigator 2.0

安全性

Navigator 3.0:该属性默认是带有污点的。有关数据污点的更多信息,请看“JavaScript 的安全性”

描述

The value of the name property initially reflects the value of the NAME attribute. Changing the name property overrides this setting.

Do not confuse the name property with the label displayed on the reset button. The value property specifies the label for this button. The name property is not displayed on the screen; it is used to refer programmatically to the button.

If multiple objects on the same form have the same NAME attribute, an array of the given name is created automatically. Each element in the array represents an individual Form object. Elements are indexed in source order starting at 0. For example, if two Text elements and a Reset element on the same form have their NAME attribute set to "myField", an array with the elements myField[0], myField[1], and myField[2] is created. You need to be aware of this situation in your code and know whether myField refers to a single element or to an array of elements.

示例

In the following example, the valueGetter function uses a for loop to iterate over the array of elements on the valueTest form. The msgWindow window displays the names of all the elements on the form:

newWindow=window.open("http://home.netscape.com") function valueGetter() {
   var msgWindow=window.open("")
   for (var i = 0; i < newWindow.document.valueTest.elements.length; i++) {
      msgWindow.document.write(newWindow.document.valueTest.elements[i].name + "<BR>")
   }
}

参看

Reset.value

type

For all Reset objects, the value of the type property is "reset". This property specifies the form element's type.

属性源Reset
只读
实现版本Navigator 3.0

示例

The following example writes the value of the type property for every element on a form.

for (var i = 0; i < document.form1.elements.length; i++) {
   document.writeln("<BR>type is " + document.form1.elements[i].type)
}

value

A string that reflects the reset button's VALUE attribute.

属性源Reset
只读
实现版本Navigator 2.0

安全性

Navigator 3.0:该属性默认是带有污点的。有关数据污点的更多信息,请看“JavaScript 的安全性”

描述

This string is displayed on the face of the button. When a VALUE attribute is not specified in HTML, the value property is the string "Reset".

Do not confuse the value property with the name property. The name property is not displayed on the screen; it is used to refer programmatically to the button.

示例

The following function evaluates the value property of a group of buttons and displays it in the msgWindow window:

function valueGetter() {
   var msgWindow=window.open("")
   msgWindow.document.write("submitButton.value is " +
      document.valueTest.submitButton.value + "<BR>")
   msgWindow.document.write("resetButton.value is " +
      document.valueTest.resetButton.value + "<BR>")
   msgWindow.document.write("helpButton.value is " +
      document.valueTest.helpButton.value + "<BR>")
   msgWindow.document.close()
}
This example displays the following values:

Query Submit
Reset
Help
The previous example assumes the buttons have been defined as follows:

<INPUT TYPE="submit" NAME="submitButton">
<INPUT TYPE="reset" NAME="resetButton">
<INPUT TYPE="button" NAME="helpButton" VALUE="Help">

参看

Reset.name

方法

blur

Removes focus from the reset button.

方法源Reset
实现版本Navigator 2.0

语法

blur()

参数

示例

The following example removes focus from the reset button userReset:

userReset.blur() This example assumes that the button is defined as

<INPUT TYPE="reset" NAME="userReset">

参看

Reset.focus

click

Simulates a mouse-click on the reset button, but does not trigger an object's onClick event handler.

方法源Reset
实现版本Navigator 2.0

语法

click()

参数

focus

Navigates to the reset button and gives it focus.

方法源Reset
实现版本Navigator 2.0

语法

focus()

参数

参看

Reset.blur

handleEvent

调用指定事件的控制句柄。

方法源Reset
实现版本Navigator 4.0

语法

handleEvent(event)

参数

event你想要调用的对象的某一事件控制句柄的名称。


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