| JavaScript手册 | |
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Password
A text field on an HTML form that conceals its value by displaying asterisks (*). When the user enters text into the field, asterisks (*) hide entries from view.
| 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 Navigator 4.0: 添加了 handleEvent 方法。 |
创建源
The HTML INPUT tag, with "password" as the value of the TYPE attribute. For a given form, the JavaScript runtime engine creates appropriate Password objects and puts these objects in the elements array of the corresponding Form object. You access a Password object by indexing this array. You can index the array either by number or, if supplied, by using the value of the NAME attribute.
描述
A Password object on a form looks as follows:
安全性
Navigator 3.0: If a user interactively modifies the value in a password field, you cannot evaluate it accurately unless data tainting is enabled. See the JavaScript Guide.
| blur | Removes focus from the object. |
| focus | Gives focus to the object. |
| handleEvent | 调用指定事件的控制句柄。 |
| select | Selects the input area of the object. |
示例
The following example creates a Password object with no default value:
<B>Password:</B>
<INPUT TYPE="password" NAME="password" VALUE="" SIZE=25>
参看
Form, Text
属性
defaultValue
A string indicating the default value of a Password object.
| 属性源 | Password |
| 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 initial value of defaultValue is null (for security reasons), regardless of the value of the VALUE attribute.
Setting defaultValue programmatically overrides the initial setting. If you programmatically set defaultValue for the Password object and then evaluate it, JavaScript returns the current value.
You can set the defaultValue property at any time. The display of the related object does not update when you set the defaultValue property, only when you set the value property.
参看
Password.value
form
An object reference specifying the form containing this object.
| 属性源 | Password |
| 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。
name
A string specifying the name of this object.
| 属性源 | Password |
| 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 name property initially reflects the value of the NAME attribute. Changing the name property overrides this setting. The name property is not displayed on-screen; it is used to refer to the objects programmatically.
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 Password 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>")
}
}
type
For all Password objects, the value of the type property is "password". This property specifies the form element's type.
| 属性源 | Password |
| 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 initially reflects the VALUE attribute.
| 属性源 | Password |
| 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”。 If you programmatically set the value property and then evaluate it, JavaScript returns the current value. If a user interactively modifies the value in the password field, you cannot evaluate it accurately unless data tainting is enabled. See the JavaScript Guide.
描述
This string is represented by asterisks in the Password object field. The value of this property changes when a user or a program modifies the field, but the value is always displayed as asterisks.
参看
Password.defaultValue
方法
blur
Removes focus from the object.
| 方法源 | Password |
| 实现版本 | Navigator 2.0 |
语法
blur()
参数
无
示例
The following example removes focus from the password element userPass:
userPass.blur()
This example assumes that the password is defined as
<INPUT TYPE="password" NAME="userPass">
参看
Password.focus, Password.select
focus
Gives focus to the password object.
| 方法源 | Password |
| 实现版本 | Navigator 2.0 |
语法
focus()
参数
无
描述
Use the focus method to navigate to the password field and give it focus. You can then either programmatically enter a value in the field or let the user enter a value.
示例
In the following example, the checkPassword function confirms that a user has entered a valid password. If the password is not valid, the focus method returns focus to the Password object and the select method highlights it so the user can reenter the password.
function checkPassword(userPass) {
if (badPassword) {
alert("Please enter your password again.")
userPass.focus()
userPass.select()
}
}
This example assumes that the Password object is defined as
<INPUT TYPE="password" NAME="userPass">
参看
Password.blur, Password.select
| 方法源 | Password |
| 实现版本 | Navigator 4.0 |
| event | 你想要调用的对象的某一事件控制句柄的名称。 |
描述
要获得关于事件句柄的更多信息，请看“关于事件的常规信息”。
select
Selects the input area of the password field.
| 方法源 | Password |
| 实现版本 | Navigator 2.0 |
语法
select()
参数
无
描述
Use the select method to highlight the input area of the password field. You can use the select method with the focus method to highlight a field and position the cursor for a user response.
示例
In the following example, the checkPassword function confirms that a user has entered a valid password. If the password is not valid, the select method highlights the password field and the focus method returns focus to it so the user can reenter the password.
function checkPassword(userPass) {
if (badPassword) {
alert("Please enter your password again.")
userPass.focus()
userPass.select()
}
}
This example assumes that the password is defined as
<INPUT TYPE="password" NAME="userPass">
参看
Password.blur, Password.focus
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