<input>
elements of type
month
create input fields that let the user enter a month and year allowing a month and year to be easily entered. The value is a string whose value is in the format "
YYYY-MM
", where
YYYY
is the four-digit year and
MM
is the month number.
The control's UI varies in general from browser to browser; at the moment support is patchy, with only Chrome/Opera and Edge on desktop — and most modern mobile browser versions — having usable implementations. In browsers that don't support
month
inputs, the control degrades gracefully to a simple
<input type="text">
, although there may be automatic validation of the entered text to ensure it's formatted as expected.
For those of you using a browser that doesn't support
month
, the screenshot below shows what it looks like in Chrome and Opera. Clicking the down arrow on the right hand side brings up a date picker that lets you select the month and year.
The Microsoft Edge
month
control looks like this:
| 值 |
A
DOMString
representing a month and year, or empty.
|
| 事件 |
change
and
input
|
| Supported common attributes |
autocomplete
,
list
,
readonly
，和
step
.
|
| IDL attributes |
value
|
| 方法 |
select()
,
stepDown()
,
stepUp()
.
|
A
DOMString
representing the value of the month and year entered into the input, in the form YYYY-MM (four or more digit year, then a hyphen ("
-
"), followed by the two-digit month). The format of the month string used by this input type is described in
Format of a valid local month string
in
用于 HTML 的日期和时间格式
.
You can set a default value for the input control by including a month and year inside the
value
attribute, like so:
<label for="bday-month">What month were you born in?</label> <input id="bday-month" type="month" name="bday-month" value="2017-06">
One thing to note is that the displayed date format differs from the actual
value
; most
user agents
display the month and year in a locale-appropriate form, based on the set locale of the user's operating system, whereas the date
value
is always formatted
yyyy-MM
.
When the above value is submitted to the server, for example, it will look like
bday-month=1978-06
.
You can also get and set the date value in JavaScript using the
HTMLInputElement.value
特性，例如：
<label for="bday-month">What month were you born in?</label> <input id="bday-month" type="month" name="bday-month" value="2017-06">
var monthControl = document.querySelector('input[type="month"]');
monthControl.value = '1978-06';
In addition to the attributes common to
<input>
elements, month inputs offer the following attributes:
| 属性 | 描述 |
|---|---|
list
|
The id of the <datalist> element that contains the optional pre-defined autocomplete options |
max
|
The latest year and month to accept as a valid input |
min
|
The earliest year and month to accept as a valid input |
readonly
|
A Boolean which, if present, indicates that the input's value can't be edited |
step
|
A stepping interval to use when incrementing and decrementing the value of the input field |
list
The values of the list attribute is the
id
的
<datalist>
element located in the same document. The
<datalist>
provides a list of predefined values to suggest to the user for this input. Any values in the list that are not compatible with the
type
are not included in the suggested options. The values provided are suggestions, not requirements: users can select from this predefined list or provide a different value.
max
The latest year and month, in the string format discussed in the
值
section above, to accept. If the
value
entered into the element exceeds this, the element fails
constraint validation
. If the value of the
max
attribute isn't a valid string in "
yyyy-MM
" format, then the element has no maximum value.
This value must specify a year-month pairing later than or equal to the one specified by the
min
属性。
min
The latest year and month to accept, in the same "
yyyy-MM
" format described above. If the
value
of the element is less than this, the element fails
constraint validation
. If a value is specified for
min
that isn't a valid year and month string, the input has no minimum value.
This value must be a year-month pairing which is earlier than or equal to the one specified by the
max
属性。
readonly
A Boolean attribute which, if present, means this field cannot be edited by the user. Its
value
can, however, still be changed from JavaScript code that directly sets the value of the
HTMLInputElement.value
特性。
注意：
Because a read-only field cannot have a value,
required
does not have any effect on inputs with the
readonly
attribute also specified.
step
step
attribute is a number that specifies the granularity that the value must adhere to, or the special value
any
, which is described below. Only values which are equal to the basis for stepping (
min
if specified,
value
otherwise, and an appropriate default value if neither of those is provided) are valid.
A string value of
any
means that no stepping is implied, and any value is allowed (barring other constraints, such as
min
and
max
).
注意： When the data entered by the user doesn't adhere to the stepping configuration, the 用户代理 may round to the nearest valid value, preferring numbers in the positive direction when there are two equally close options.
For
month
inputs, the value of
step
is given in months, with a scaling factor of 1 (since the underlying numeric value is also in months). The default value of
step
is 1 month.
Date-related inputs (including
month
) sound convenient at first glance; they promise an easy UI for choosing dates, and they normalize the data format sent to the server, regardless of the user's locale. However, there are issues with
<input type="month">
because at this time, many major browsers don't yet support it.
We'll look at basic and more complex uses of
<input type="month">
, then offer advice on mitigating the browser support issue in the section
Handling browser support
).
The simplest use of
<input type="month">
involves a basic
<input>
and
<label>
element combination, as seen below:
<form> <label for="bday-month">What month were you born in?</label> <input id="bday-month" type="month" name="bday-month"> </form>
可以使用
min
and
max
attributes to restrict the range of dates that the user can choose. In the following example we specify a minimum month of
1900-01
and a maximum month of
1999-12
:
<form>
<label for="bday-month">What month were you born in?</label>
<input id="bday-month" type="month" name="bday-month"
min="1900-01" max="1999-12">
</form>
The result here is that:
<input type="month">
doesn't support form sizing attributes such as
size
. You'll have to resort to
CSS
for sizing needs.
默认情况下，
<input type="month">
does not apply any validation to entered values. The UI implementations generally don't let you enter anything that isn't a date — which is helpful — but you can still submit the form with the
month
input empty, or enter an invalid date (e.g. the 32nd of April).
To help avoid this, you can use
min
and
max
to restrict the available dates (see
Setting maximum and minimum dates
), and in addition use the
required
attribute to make filling in the date mandatory. As a result, supporting browsers will display an error if you try to submit a date that is outside the set bounds, or an empty date field.
Let's look at an example; here we've set minimum and maximum dates, and also made the field required:
<form>
<div>
<label for="month">What month would you like to visit us (Summer months only, please)?</label>
<input id="month" type="month" name="month"
min="2017-06" max="2017-09" required>
<span class="validity"></span>
</div>
<div>
<input type="submit" value="Submit form">
</div>
</form>
If you try to submit the form without both the month and year specified (or with a date outside the set bounds), the browser displays an error. Try playing with the example now:
Here's a screenshot for those of you who aren't using a supporting browser:
Here's the CSS used in the above example. Here we make use of the
:valid
and
:invalid
CSS properties to style the input based on whether or not the current value is valid. We had to put the icons on a
<span>
next to the input, not on the input itself, because in Chrome the generated content is placed inside the form control, and can't be styled or shown effectively.
div {
margin-bottom: 10px;
position: relative;
}
input[type="number"] {
width: 100px;
}
input + span {
padding-right: 30px;
}
input:invalid+span:after {
position: absolute;
content: '✖';
padding-left: 5px;
}
input:valid+span:after {
position: absolute;
content: '✓';
padding-left: 5px;
}
重要 : HTML form validation is not a substitute for scripts that ensure that the entered data is in the proper format. It's far too easy for someone to make adjustments to the HTML that allow them to bypass the validation, or to remove it entirely. It's also possible for someone to simply bypass your HTML entirely and submit the data directly to your server. If your server-side code fails to validate the data it receives, disaster could strike when improperly-formatted data is submitted (or data which is too large, of the wrong type, and so forth).
As mentioned above, the major problem with using date inputs at the time of writing is that many major browsers don't yet implement them all; only Chrome/Opera and Edge support it on desktop, and most modern browsers on mobile. As an example, the
month
picker on Chrome for Android looks like this:
Non-supporting browsers gracefully degrade to a text input, but this creates problems both in terms of consistency of user interface (the presented control will be different), and data handling.
The second problem is the more serious of the two. As mentioned earlier, with a
month
input the actual value is always normalized to the format
yyyy-mm
. On the other hand, in its default configuration, a
text
input has no idea what format the date should be in, and this is an issue because of the number of different ways in which people write dates. For example:
mmyyyy
(072018)
mm/yyyy
(07/2018)
mm-yyyy
(07-2018)
yyyy-mm
(2018-07)
Month yyyy
(July 2018)
One way around this is to put a
pattern
attribute on your
month
input. Even though the
month
input doesn't use it, if the browser falls back to treating it like a
text
input, the pattern will be used. For example, try viewing the following demo in a browser that doesn't support
month
inputs:
<form>
<div>
<label for="month">What month would you like to visit us? (Summer months only, yyyy-mm)</label>
<input id="month" type="month" name="month"
min="2017-06" max="2017-09" required
pattern="[0-9]{4}-[0-9]{2}">
<span class="validity"></span>
</div>
<div>
<input type="submit" value="Submit form">
</div>
</form>
If you try submitting it, you'll see that the browser now displays an error message (and highlights the input as invalid) if your entry doesn't match the pattern
nnnn-nn
，其中
n
is a number from 0 to 9. Of course, this doesn't stop people from entering invalid dates (such as
0000-42
), or incorrectly formatted dates that follow the pattern.
There's also the problem that the user won't necessarily know which of the many date formats is expected. We have work left to do.
div {
margin-bottom: 10px;
position: relative;
}
input[type="number"] {
width: 100px;
}
input + span {
padding-right: 30px;
}
input:invalid+span:after {
position: absolute;
content: '✖';
padding-left: 5px;
}
input:valid+span:after {
position: absolute;
content: '✓';
padding-left: 5px;
}
The best way to deal with dates in forms in a cross-browser way (until all of the major browsers have supported them for a while) is to get the user to enter the month and year in separate controls (
<select>
elements being popular; see below for an implementation), or use JavaScript libraries such as the
jQuery date picker
插件。
In this example, we create two sets of UI elements, each designed to let the user select a month and year. The first is a native
month
input, and the other is a pair of
<select>
elements that allow choosing a month and year independently, for compatibility with browsers that don't yet support
<input type="month">
.
The form that requests the month and year looks like this:
<form>
<div class="nativeDatePicker">
<label for="month-visit">What month would you like to visit us?</label>
<input type="month" id="month-visit" name="month-visit">
<span class="validity"></span>
</div>
<p class="fallbackLabel">What month would you like to visit us?</p>
<div class="fallbackDatePicker">
<div>
<span>
<label for="month">Month:</label>
<select id="month" name="month">
<option selected>January</option>
<option>February</option>
<option>March</option>
<option>April</option>
<option>May</option>
<option>June</option>
<option>July</option>
<option>August</option>
<option>September</option>
<option>October</option>
<option>November</option>
<option>December</option>
</select>
</span>
<span>
<label for="year">Year:</label>
<select id="year" name="year">
</select>
</span>
</div>
</div>
</form>
<div>
with the ID
nativeDatePicker
使用
month
input type to request the month and year, while the
<div>
with the ID
fallbackDatePicker
instead uses a pair of
<select>
elements. The first requests the month, and the second the year.
<select>
for choosing the month is hardcoded with the names of the months, as they don't change (leaving localization out of things). The list of available year values is dynamically generated depending on the current year (see the code comments below for detailed explanations of how these functions work).
div {
margin-bottom: 10px;
position: relative;
}
input[type="number"] {
width: 100px;
}
input + span {
padding-right: 30px;
}
input:invalid+span:after {
position: absolute;
content: '✖';
padding-left: 5px;
}
input:valid+span:after {
position: absolute;
content: '✓';
padding-left: 5px;
}
The JavaScript code that handles selecting which approach to use and to set up the list of years to include in the non-native year
<select>
follows.
The part of the example that may be of most interest is the feature detection code. In order to detect whether the browser supports
<input type="month">
, we create a new
<input>
element, try setting its
type
to
month
, then immediately check what its type is set to. Browsers that don't support type
month
将返回
text
, since that's What month falls back to when not supported. If
<input type="month">
is not supported, we hide the native picker and show the fallback picker UI instead.
// define variables
var nativePicker = document.querySelector('.nativeDatePicker');
var fallbackPicker = document.querySelector('.fallbackDatePicker');
var fallbackLabel = document.querySelector('.fallbackLabel');
var yearSelect = document.querySelector('#year');
var monthSelect = document.querySelector('#month');
// hide fallback initially
fallbackPicker.style.display = 'none';
fallbackLabel.style.display = 'none';
// test whether a new date input falls back to a text input or not
var test = document.createElement('input');
try {
test.type = 'month';
} catch (e) {
console.log(e.description);
}
// if it does, run the code inside the if() {} block
if(test.type === 'text') {
// hide the native picker and show the fallback
nativePicker.style.display = 'none';
fallbackPicker.style.display = 'block';
fallbackLabel.style.display = 'block';
// populate the years dynamically
// (the months are always the same, therefore hardcoded)
populateYears();
}
function populateYears() {
// get the current year as a number
var date = new Date();
var year = date.getFullYear();
// Make this year, and the 100 years before it available in the year <select>
for(var i = 0; i <= 100; i++) {
var option = document.createElement('option');
option.textContent = year-i;
yearSelect.appendChild(option);
}
}
注意 : Remember that some years have 53 weeks in them (see Weeks per year )! You'll need to take this into consideration when developing production apps.
| 规范 | 状态 | 注释 |
|---|---|---|
|
HTML 实时标准
The definition of '<input type="month">' in that specification. |
实时标准 |
| 桌面 | 移动 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
type="month"
|
Chrome 完整支持 20 | Edge 完整支持 12 |
Firefox
不支持
No
注意事项
|
IE 不支持 No | Opera 完整支持 11 |
Safari
不支持
No
注意事项
|
WebView Android 完整支持 Yes | Chrome Android 完整支持 Yes | Firefox Android 不支持 No | Opera Android 完整支持 Yes | Safari iOS 完整支持 Yes | Samsung Internet Android 完整支持 Yes |
完整支持
不支持
见实现注意事项。
<input>
element and the interface used to manipulate it,
HTMLInputElement
<input type="datetime-local">
,
<input type="date">
,
<input type="time">
，和
<input type="week">
<input>
类型
<input type="button">
<input type="checkbox">
<input type="color">
<input type="date">
<input type="datetime">
<input type="datetime-local">
<input type="email">
<input type="file">
<input type="hidden">
<input type="image">
<input type="month">
<input type="number">
<input type="password">
<input type="radio">
<input type="range">
<input type="reset">
<input type="search">
<input type="submit">
<input type="tel">
<input type="text">
<input type="time">
<input type="url">
<input type="week">