Manual:Messages API

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MediaWiki 信息 可通过 Message 类及其相关方法在代码中使用。

信息参数

某些信息需要参数。 它们在(静态)信息文本中分别用 $1, $2, $3, ...表示,并在运行时被替换。 典型的参数值是数字("是否删除版本3?"中的“3”)或用户名("页面最后编辑者为 Bob "中的“Bob”)、页面名、链接等,有时还有其他信息。 它们的复杂程度可以随心所欲。

为每条特定消息定义的参数列表都放在 MediaWiki的"languages/"文件夹下的特殊文件"qqq.json"中--更多信息请参阅消息文档

最好使用带有"复数"、"性别"和 "语法"魔法词的整词。 例如,{{PLURAL:$1|subpage|subpages}} 就比 sub{{PLURAL:$1|page|pages}} 來得好. 它使得搜索更容易。

Referring to other messages

It's sometimes convenient to refer to sub-messages in a message, e.g. in phrases like "Use the X button" or "Visit the Y page", to ensure that the translations are consistent. To do so, you may use the following syntax:

  • {{int:X}} - to use the sub-message in interface language. This is often used when referring to form buttons or site navigation, e.g. showpreview.
  • {{MediaWiki:Y}} - to use the sub-message in content language. This is used when the sub-message defines a translatable name of a local page, e.g. mainpage, grouppage-sysop, policy-url.
  • {{#Special:Z}} - to use the name of a special page in content language.

If you need anything more complicated (e.g. the sub-message used depends on configuration), parse it in your code and pass the whole sub-message as a parameter.

Example:

Before saving, use the {{int:foo-test}} button to test the changes. Visit [[{{MediaWiki:foo-help}}|the help page]] to learn more.Customize this feature at [[{{#Special:Preferences}}]].

Switches in messages…

Parameters values at times influence the exact wording, or grammatical variations in messages. We don't resort to ugly constructs like "$1 (sub)page(s) of his/her userpage", because these are poor for users and we can do better. Instead, we make switches that are parsed according to values that will be known at run time. The static message text then supplies each of the possible choices in a list, preceded by the name of the switch, and a reference to the value that makes a difference. This resembles the way 解析器函数 are called in MediaWiki. Several types of switches are available. These only work if you do full parsing, or {{-transformation, for the messages.

…on numbers via PLURAL

MediaWiki supports plurals, which makes for a nicer-looking product. For example:

'undelete_short' => 'Undelete {{PLURAL:$1|one edit|$1 edits}}',

If there is an explicit plural form to be given for a specific number, it is possible with the following syntax:

'Box has {{PLURAL:$1|one egg|$1 eggs|12=a dozen eggs}}.'
Be aware of PLURAL use on all numbers


When a number has to be inserted into a message text, be aware that some languages will have to use PLURAL on it even if always larger than 1. The reason is that PLURAL in languages other than English can make very different and complex distinctions, comparable to English 1st, 2nd, 3rd, 4th, … 11th, 12th, 13th, … 21st, 22nd, 23rd, … etc.

Do not try to supply three different messages for cases like "no items counted", "one item counted", "more items counted". Rather, let one message take them all, and leave it to translators and PLURAL to properly treat any possible differences of presentation for them in their respective languages.

Always include the number as a parameter if possible. Always add {{PLURAL:}} syntax to the source messages if possible, even if it makes no sense in English. The syntax guides translators.

Fractional numbers are supported, but the plural rules may not be complete.

将列表项的数量作为参数传递给有关列表的信息

不要以为這只是单数和复数的差別。 许多语言都有两种以上的形式,这取决于实际使用的数量,在表达读者可以看到的列表中列出的内容时,它们必须使用语法随列表项数量而变化的形式。 因此,只要您的代码计算出一个列表,就应在标题、引言、页脚和其他有关列表的信息中加入count( $list )作为参数,即使在英文中不使用计数。 有一种中性的方法来考慮隐形列表,这样你就可以在额外页面上使用列表的链接,而不必事先计數项的数量。

...基於性別的用户名

'foobar-edit-review' => 'Please review {{GENDER:$1|his|her|their}} edits.'

如果在信息中提及用户,请将用户名作为参数传递给信息,并在信息文档中添加支持性別的說明 如果GENDER很可能會用於性別變化語言的翻譯,請在英語源消息中明確添加它。

如果直接称呼当前登录的用户,则用户名参数留空:

'foobar-logged-in-user' => 'You said {{GENDER:|you were male|you were female|nothing about your gender}}.'
MediaWiki版本:
1.31
Gerrit change 398772

如果在信息中包含用户名(如"$1感谢了您。"),请考虑先通过 wfEscapeWikitext(),以确保像 *; 这样的字符不会被解析。

用户在语法上有性别之分


当一条信息涉及某个用户、与某个用户有关或直接针对某个用户时,应将用户名作为参数传递给信息。 因此,那些必须使用或希望使用适当的性别相关语法的语言可以做到这样。 即使用户名并不打算出现在消息中,也应该这样做,比如“在用户的对话页中通知他/她”,這在英文中最好是写成“在用户的对话页中通知{{GENDER:$1|他|她|他们}}”。

这并不意味着是鼓励您将信息的语言“性別化”:请使用性别中性的语言,只要能做到清晰准确。

…on use context inside sentences via GRAMMAR

Grammatical transformations for agglutinative language (Q171263) is also available. For example for Finnish, where it was an absolute necessity to make language files site-independent, i.e. to remove the Wikipedia references. In Finnish, "about Wikipedia" becomes "Tietoja Wikipediasta" and "you can upload it to Wikipedia" becomes "Voit tallentaa tiedoston Wikipediaan". Suffixes are added depending on how the word is used, plus minor modifications to the base. There is a long list of exceptions, but since only a few words needed to be translated, such as the site name, we didn't need to include it.

MediaWiki has grammatical transformation functions for over 20 languages. Some of these are just dictionaries for Wikimedia site names, but others have simple algorithms which will fail for all but the most common cases.

Even before MediaWiki had arbitrary grammatical transformation, it had a nominative/genitive distinction for month names. This distinction is necessary for some languages if you wish to substitute month names into sentences.

Filtering special characters in parameters and messages

The other (much simpler) issue with parameter substitution is HTML escaping. Despite being much simpler, MediaWiki does a pretty poor job of it.

Using messages in PHP

警告 警告: Make sure you always use one of the output modes mentioned below

Here is a simple example:

$out = Xml::submitButton( wfMessage( 'submit' )->text() );

wfMessage() is a global function which acts as a wrapper for the Message class, creating a Message object. This example then invokes Message method text() which fetches the text of the 'submit' message in the current language, performs certain language transformations (such as gender and plural), and returns the unescaped message text.

Here is a more complex example using a message that takes a count and supports linguistic plural handling:

$out = Xml::label( wfMessage( 'numberofpages' )->numParams( $count )->text() );

The following sections explain the code.

参数

给出类似下列的消息:

{
    "msg": "Values are $1, $2"
}

You pass parameters to messages that need them in several ways:

wfMessage( 'msg', 'param1', 'param2' )->plain();
wfMessage( 'msg' )->params( 'param1', 'param2' )->plain();
wfMessage( 'msg', [ 'param1', 'param2' ] )->plain();

The first approach is most common, use the second approach when mixing different types of parameters, and you can use the third to construct message objects dynamically from other data. There are different types of parameters:

wfMessage( 'msg' )->params( $username )->plain();
wfMessage( 'msg' )->rawParams( $link )->plain();
wfMessage( 'msg' )->plaintextParams( $userInput )->plain();

wfMessage( 'msg' )->numParams( $count )->plain();
wfMessage( 'msg' )->durationParams( $duration )->plain(); // MediaWiki 1.22+
wfMessage( 'msg' )->expiryParams( $expiry )->plain(); // MediaWiki 1.22+
wfMessage( 'msg' )->timeperiodParams( $period )->plain(); // MediaWiki 1.22+
wfMessage( 'msg' )->sizeParams( $size )->plain(); // MediaWiki 1.22+
wfMessage( 'msg' )->bitrateParams( $bitrate )->plain(); // MediaWiki 1.22+
params()
Normal message substitution parameter.
rawParams()
Substitutes the parameter after the message has been otherwise processed; this means that these parameters are not available to parser functions, nor are they escaped if escaping output format is used (see below). Make sure you escape them properly yourself.
plaintextParams()
Like rawParams(), but does escaping. It is useful when you pass user input that may contain wikitext that should not be parsed.

Each function from the second group formats the value in a specific way before the substitution. numParams() must be used if the message uses {{PLURAL:}}. In some cases you might not want to use it even though you have a number, for example a revision ID. The other functions correspond to Language functions formatDuration, formatExpiry, formatTimePeriod, formatSize and formatBitrate, and are just shorthands for calling them directly.


Language

To override the language in which you want the message, there is one method and one shortcut for the common case of using wiki content language. In the latter case you can use either a language code or a language object. The usual language fallback chains apply, so the actual message you get may be in a different language than requested, if a translation does not exist.

wfMessage( 'message-key' )->inContentLanguage();
wfMessage( 'message-key' )->inLanguage( $lang );

Output modes and escaping

The Message class, and thus the object returned by wfMessage(), has five output modes:

  • plain() - returns the message text as-is; only parameters are substituted[1]
  • text() - transforms the message text (see MessageCache::transform()) which transforms all {{}} including templates and parser functions like PLURAL and GENDER, but neither escapes nor sanitizes
  • escaped() - same as 'text', but also escapes it for use in HTML
  • parse() - parses the message text from wikitext to HTML and sanitizes (MessageCache::parse() which calls the Parser)
  • parseAsBlock() - the output is wrapped in a block level HTML element, if not already, similarly to OutputPage::addWikiMsg

Remember that Html:: functions escape everything fed into them, so use the text() format with those to avoid double escaping. Hence the most common output format is text(). Also, make sure to use parse() or parseAsBlock() if the message has wikitext in it, otherwise the wikitext will just be escaped and output as plain text.

When using wfMessage() or $this->msg(), you should always specify an output type. text() is appropriate when you're outputting it through addWikiText().

Which output mode to use

Generally speaking, the most common modes you will use are ->parse() and ->text(). You use ->parse() in most places where html markup is supported, and you use ->text() in places where the content is going to become html escaped or html markup is not supported.

Some common cases:

  • If you are putting the message in the text part (third argument) of Html::element use ->text(). You may also consider using Html::rawElement() instead and using the ->parse() mode.
  • If you are putting in text (third argument) of Html::rawElement(), you should generally use ->parse().
  • If you are putting into the attributes (second argument) of Html::rawElement() or Html::element(), use ->parse()
  • If you are manually constructing html attributes, you should use ->escaped(). However you should never manually construct html attributes
  • For $out->addWikiText() where $out is an OutputPage object use ->text() or ->plain(). However consider if you would rather use $out->addWikiMsg instead.
  • For $out->addHTML() use ->parse()

Method chaining

Most Message methods return the current object, so you can conveniently call one after another to operate on an object before finally returning its text. This is called method chaining. Here is an example:

wfMessage( 'key' )
	->params( 'apple' )
	->numParams( $numOfApples )
	->setContext( $context )
	->inContentLanguage()
	->parse()

Additional methods of printing messages

The general message function in MediaWiki is wfMessage. However, since in a message the value of magic words can depend on the context, there are various wrappers to this function, that automatically set the correct context.

OutputPage has a few methods that append directly to the generated output. The useful ones are:

$out->addWikiMsg( 'pageheader' );
$out->wrapWikiMsg( '<div class="error">\n$1\n</div>', [ 'someerrormessage', $user->getName() ] );

Both of the above parse the wikitext in the context of the current page before appending it to output buffer.

Classes extending ContextSource have a method msg that automatically sets the current context (language, current page etc.). It is therefore recommended to use $this->msg() for those classes, like special pages. Here is a non-exhaustive list of such classes:[2]

  • CategoryViewer
  • HTMLForm
  • LogEventsList
  • DifferenceEngine
  • OutputPage
  • IndexPager
  • ImageHistoryList
  • ApiBase
  • ChangesList
  • Skin
警告 警告: The QuickTemplate class and its subclasses (BaseTemplate) have a method named msg which is different from the one from ContextSource. In these classes $this->msg() will simply output the escaped text of the message.

Examples of correct usage:

wfMessage( 'key' )->numParams( 567 )->text();
$this->msg( 'key' )->numParams( 567 )->parse();

Examples of incorrect usage:

wfMessage( 'key', 345 )->parseInline(); # Number is not formatted correctly
$this->msg( 'key', 345 )->numParams( 234 )->plain() # Plural syntax is not converted in plain format

Using messages in JavaScript

This page only deals with MediaWiki core. See the specific documentation instead for the jquery.i18n module.

Getting the messages to the client

To use the messages, we need to make sure that the messages are available at client side first. This can be done using either a ResourceLoader module (most common) or an API query from JavaScript (rare).

Using a ResourceLoader module

This is the most common method of delivering messages. You should use this unless you have a good reason not to.

We are going to use ResourceLoader to make sure that the messages are available at the client side. For this, in your ResourceLoader modules, define the messages to be exported to the client side.

If you plan to use the mw.message(…).parse() to generate HTML from wikitext in interface messages, then it is important to load the mediawiki.jqueryMsg module.

Example (extension.json):

{
	"ResourceModules": {
		"ext.abuseFilter.edit": {
			"scripts": "ext.abuseFilter.edit.js",
			"messages": [
				"abusefilter-edit-syntaxok",
				"abusefilter-edit-syntaxerr",
				"abusefilter-http-error",
				"abusefilter-edit-throttle-placeholder",
				"abusefilter-edit-tag-placeholder",
				"abusefilter-edit-warn-leave",
				"unknown-error",
				"jan",
				"feb",
				"mar"
			],
			"dependencies": [
				"mediawiki.util",
				"mediawiki.api",
				"mediawiki.confirmCloseWindow",
				"jquery.textSelection",
				"jquery.spinner",
				"oojs-ui-core",
				"oojs-ui-widgets"
			]
		}
	}
}

Using an API query from JavaScript

This is not a common way of loading messages. You should only use this if there is a good reason why you can't use the ResourceLoader module method above.

You can use the following code:

MediaWiki版本:
1.27
// When: The 'mediawiki.api' module is loaded, and, the page is ready
$.when( mw.loader.using( [ 'mediawiki.api', 'mediawiki.jqueryMsg' ] ), $.ready )
    // Then: Load the messages that you need (if they are not yet loaded)
    .then( function() {
        return new mw.Api().loadMessagesIfMissing( [ 'january', 'february', 'march' ] );
    } )
    // Then: Do stuff with them
    .then( doStuff );

To get the messages in some language other than the UserLanguage language, use getMessages instead of loadMessagesIfMissing, and supply the target language as the "amlang" field of the optional second parameter, like so:

// When: The 'mediawiki.api' module is loaded. No need to wait for the page to be ready.
$.when( mw.loader.using( [ 'mediawiki.api' ] ) )
    // Then: get some messages in French (language code 'fr')
    .then( function() {
        return new mw.Api().getMessages( [ 'january', 'february', 'march' ], { amlang: 'fr' }  );
    } )
    // Then: Do stuff with them
    .then( doStuff );
// doStuff is a function that will receive as its first parameter an object that looks like so:
// { february: "février", january: "janvier", march: "mars" }

For older MediaWiki versions before 1.27, use the following:

/** @return instance of jQuery.Promise */
function loadMessages( messages ) {
	return new mw.Api().get( {
		action: 'query',
		meta: 'allmessages',
		ammessages: messages.join( '|' ),
		amlang: mw.config.get( 'wgUserLanguage' )
	} ).then( function ( data ) {
		$.each( data.query.allmessages, function ( i, message ) {
			if ( message.missing !== '' ) {
				mw.messages.set( message.name, message['*'] );
			}
		} );
	} );
}

loadMessages( [ 'january', 'february', 'march' ] ).then( doStuff );


Use of the messages

The messages defined in the above example will be available at client side and can be accessed by mw.message( 'message-key-name' ).

For example:

$( '<div>' ).text( mw.message( 'translate-msggroupselector-projects' ).text() );

Note how we use jQuery text method to escape our output properly when using mw.message text format.

If your message contains wikitext formatting, you can instead use the following:

$( '<div>' ).append( mw.message( 'translate-msggroupselector-projects' ).parseDom() );

Here we use jQuery append method to insert the DOM nodes returned by mw.message parseDom format.

In older code you might also encounter the following: (parseDom was not available until MediaWiki 1.27)

$( '<div>' ).html( mw.message( 'translate-msggroupselector-projects' ).escaped() );
$( '<div>' ).html( mw.message( 'translate-msggroupselector-projects' ).parse() );

There are other correct combinations, but whenever possible, stick to the patterns above to avoid XSS vulnerabilities and make your code easier to understand for others.

We can also pass the dynamic parameters to the message (i.e. the values for $1, $2, etc.) as shown below.

$( '<div>' ).text( mw.message( 'hello-user', username ).text() );

In the above examples, note that the message should be defined in an i18n file. If the message key is not found in any i18n file, the result will be the message key in curved angle brackets U+29FC/U+29FD (part of mathematical symbols), like '⧼message-key-foo⧽'. In older versions of MediaWiki, the message key was returned in ASCII angle brackets, like '<message-key-foo>', and this could generate invalid or fake HTML elements. In the case where the message key does not exists, the .exists() method of the returned message object will also return false instead of true.

To use a message that must not go through the parser (e.g. when passing JSON data as messages, or when the message will be used as preloaded text of a page), use:

mw.message( 'foobar' ).plain()

Format options

If you don't specify the output format, mw.message just returns a Message object. To output the message itself, you should specify an output format. The formats are mostly the same as in PHP side:

  • mw.message( 'foobar' ).plain() Returns the message text as-is; only parameters are substituted.
  • mw.message( 'foobar' ).text() Transforms the message text (all supported {{}} blocks are replaced with transformed results). See #Feature support in JavaScript for details of what is supported. For example, certain keywords ({{int:}} (but only without parameters), {{GENDER}}, {{SITENAME}} etc.) work, but tranclusion (e.g. {{MediaWiki:}}) and server-side Magic words such as {{NUMBEROFEDITS}} or {{ns:Project}} do not work,
  • mw.message( 'foobar' ).escaped() HTML escaped version of text.
  • mw.message( 'foobar' ).parse() Parses the message text from wikitext to HTML. This supports everything from text mode, as well as most links, and allow listed HTML.
  • mw.message( 'foobar' ).parseDom() Like parse(), but returns a jQuery collection instead of a HTML string.
警告 警告: If the mediawiki.jqueryMsg module is not loaded, all of the above methods behave essentially like plain() with possible escaping.
There is no equivalent of parseAsBlock. Where necessary, wrap the output in a block element yourself.

Parameters

Parameters can be specified as additional arguments to mw.message(). They can be passed as strings or as DOM nodes / jQuery collections.

Unlike in PHP, wikitext in the parameters is not parsed. Effectively, all string parameters behave like plaintextParams().

DOM/jQuery parameters can be used to achieve the equivalent of rawParams().

There is no support for other parameter formats. Instead of numParams(), you must format numbers before passing them as parameters, using mw.language.convertNumber().

$( '<div>' ).text( mw.message( 'translate-msggroupselector-view-subprojects', mw.language.convertNumber( count ) ).text() );

Feature support in JavaScript

警告 警告: Wikitext support in JS messages requires the mediawiki.jqueryMsg module to be loaded, otherwise these features will be silently ignored.

JavaScript messages only support a small subset of wikitext syntax. Supported features include:

  • Internal links (except pipe trick)
  • Explicit external links (no auto-numbered and free links)
  • The magic words SITENAME, PAGENAME, PAGENAMEE, (in MW 1.38+) SERVERNAME
  • The parser functions PLURAL, GENDER, GRAMMAR, int, ns, formatnum, lc, uc, lcfirst, ucfirst
  • HTML tags which are allowed in wikitext (HTML must be well-formed)
  • HTML entities &#039;, &quot;, &lt;, &gt;, &amp;
  • The ‎<nowiki> tag

Notable wikitext syntax that is not supported:

  • Templates
  • Non-local interwiki links
  • All other parser functions and magic words
  • Modules (for example Module:String)
  • All other XML-like tags (extension tags)
  • Bold and italic ''', '' (use ‎<b>, ‎<i> instead)
  • Lists using *, # (use ‎<ul> or ‎<ol>, ‎<li> instead)
  • Definition lists / indents using ;, : (use ‎<dl>, ‎<dt>, ‎<dd> instead)
  • Multiple paragraphs (use ‎<p> instead)
  • Self-closing HTML tags
  • Comments <!-- -->
  • Some types of nesting (e.g. {{PLURAL:$1|<strong>$1</strong>}})

The doc-jqueryMsg template can be used to document such messages, to let translators know which wikitext restrictions apply.

mw.msg

The mw.msg() function is commonly used as a shortcut for mw.message().text().

Exporting messages through ResourceLoader callbacks

If you need to process a message on the server and send the result to the client (e.g. because you need to parse the message using parsing features that aren't supported in JS), you can do that with a package files callback in your ResourceLoader module. When you do this, take care to use $context->msg(), because using wfMessage() will cause errors.

Using messages in Lua

Modules written in Lua using Scribunto run similarly to templates and have access to MediaWiki messages. The MediaWiki Lua library includes the mw.message class for processing messages. Refer to the full Lua message library documentation for the full API. Here is a simple example:

local p = {}

function p.nmembers( frame )
	local nmembersMsg = mw.message.new( 'nmembers' )
	nmembersMsg:numParams( 3 ) -- This ensures number localization
	-- Show the message in the language of the wiki. frame:preprocess expands the {{plural}} clause.
	return frame:preprocess( nmembersMsg:plain() )
end

return p

Notes about gender, grammar, plural

See also #Switches in messages…; the syntax itself is documented at Help:Magic words#Localization and related.

In general, GENDER, GRAMMAR and PLURAL magic words work identically in both PHP and JavaScript sides.

  1. You must use text, escaped, parse or parseAsBlock output formats for them to work.
  2. You need to pass the relevant parameter as normal parameter to the message.
    • The parameter is the number for PLURAL; the plain text or wikitext-escaped username for GENDER in PHP; the gender from preferences or a user object for GENDER in JavaScript (see below).
    • For enabling plural and correct number localization in PHP, you need to use numParams for the number, see also #Chaining.
    • For enabling plural and correct number localization in JavaScript, you need to use mw.language.convertNumber for the number

PLURAL syntax example

# Simple plural
'key' => '$1 crying {{PLURAL:$1|baby|babies}}'

GENDER in JavaScript

This needs explicit jqueryMsg, see #Using messages in JavaScript.

If you have a message, say, "message-key-gender-foo": "{{GENDER:$1|he|she|they}} created an article", in JavaScript, you can use it as given below:

mw.message( 'message-key-gender-foo', 'male' ).text(); // returns 'he created an article'
mw.message( 'message-key-gender-foo', 'female' ).text(); // returns 'she created an article'
mw.message( 'message-key-gender-foo', 'unknown' ).text(); // returns 'they created an article'

Instead of passing the gender directly, we can pass any "User-like" object with a gender option. For example, the current user object mw.user.

var user = mw.user; // current user
mw.message( 'message-key-gender-foo', user ).text(); // The message returned will be based on the gender of the current user.

If the gender passed is invalid or unknown, the gender neutral form will be used as defined for each language. Pass 'unknown' if you intentionally want the neutral form.

Finally, if you want to use the gender of the current user, you can pass an empty string:

// the following line illustrates the message content, you can run this snippet on developer console
mw.messages.set( 'message-key-gender-foo', '{{GENDER:$1|male|female|unknown}}' );
mw.user.options.values.gender = 'female'; // temporarily manipulate your gender preference
mw.message( 'message-key-gender-foo', '' ).text(); // return value depends on your gender preference

PLURAL in JavaScript

This needs explicit jqueryMsg, see #Using messages in JavaScript.

If you have a message, say 'message-key-plural-foo' => 'There {{PLURAL:$1|is|are}} $1 {{PLURAL:$1|item|items}}' , in JavaScript, you can use it as given below:

mw.message( 'message-key-plural-foo', count ).text();
// returns 'There is 1 item' if count = 1
// returns 'There are 6 items' if count = 6

Help with replacing deprecated wfMsg* functions

These functions were removed starting with MediaWiki 1.27 LTS.

The code using these functions often has incorrect escaping and other code quality issues, so it's also recommended to

  • replace all Xml:: functions with their Html:: equivalents, which make it easier to do the right thing;[3]
  • where possible, avoid globals and use msg() (see above);
  • replace htmlspecialchars() with ->escaped() where appropriate.
Code change Description
Instead of:
wfMsg( 'key' );

write:

wfMessage( 'key' )->text();
 
Instead of:
wfMsgExt( 'key', SOME_FORMAT, 'apple' );

write:

wfMessage( 'key', 'apple' )->SOME_FORMAT_FUNCTION();
The second parameter specifies the output mode, usually expressed as an array like array( 'escape' ) but sometimes just like 'escape': it needs to be replaced according to #Output modes and escaping, like ->escaped().
Instead of:
wfMsgExt( 'key', array( 'parse' ), 'apple' );

write:

wfMessage( 'key', 'apple' )->parseAsBlock();
Use full parsing, and wrap the output in block-level HTML tags.
Instead of:
wfMsgExt( 'key', array( 'parseinline' ), 'apple' );

write:

wfMessage( 'key', 'apple' )->parse();
Use full parsing. Parseinline is used because it is more useful when pre-building HTML. In normal use it is better to use OutputPage::(add|wrap)WikiMsg.
Instead of:
wfMsgExt( 'key', array( 'parsemag' ), 'apple', 'pear' );

write:

wfMessage( 'key', 'apple', 'pear' )->text();
Places where HTML cannot be used. {{-transformation is done.
Instead of
wfMsgHtml( 'key', 'apple' );

write:

wfMessage( 'key' )->rawParams( 'apple' )->escaped();
wfMsgHtml does not escape parameters: to get the same result you need to use rawParams; check that the parameter really is safe for HTML output. If the message is then output as HTML, you must use escaped() for security: it will escape the parameters too and that's not always wanted, although it doesn't matter e.g. when the parameter is a number.
Instead of:
wfMsgForContent( 'key' );

write:

wfMessage( 'key' )->inContentLanguage()->text();
Get a message in the wiki's content language ($wgLanguageCode ).
Instead of:
wfMsgForContentNoTrans( 'key' );

write:

wfMessage( 'key' )->inContentLanguage()->plain();
Get a message in the wiki's content language ($wgLanguageCode ) but don't transform the message.
Instead of:
wfEmptyMsg( 'key', $message = wfMsgForContent( 'key' ) );

write:

wfMessage( 'key' )->inContentLanguage()->isBlank();
Checks if the 'key' message in the wiki's content language is empty. Often, isDisabled() is a more appropriate check and should be used instead.
Instead of:
wfMsgReal( $error['message'], $error['params'] );

write:

?
There is no simple replacement, depends on parameters. Should never have been used in the first place.
Instead of:
wfMsgGetKey

write:

?
There is no simple replacement, depends on parameters. Should never have been used in the first place.


See also

Notes

  1. While using this mode to display HTML content is possible, it is recommended to use wikitext and use the parse() mode to transform it into HTML.
  2. More in general, use $this->msg() in non-static functions of IContextSource objects.
  3. For instance Xml::tags() doesn't escape.