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/*
* JGrapes Event Driven Framework
* Copyright (C) 2017-2022 Michael N. Lipp
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License
* for more details.
*
* You should have received a copy of the GNU Affero General Public License along
* with this program; if not, see ,
Locale> LOCALE_LIST = new DefaultMultiValueConverter<>(
ArrayList::new, Converters.LANGUAGE);
private String cookieName = LanguageSelector.class.getName();
private long cookieMaxAge = Duration.ofDays(365).toSeconds();
private SameSiteAttribute cookieSameSite = SameSiteAttribute.LAX;
/**
* Creates a new language selector component with its channel set to
* itself and the scope set to "/". The handler's priority
* is set to 990.
*/
public LanguageSelector() {
this("/");
}
/**
* Creates a new language selector component with its channel set to
* itself and the scope set to the given value. The handler's priority
* is set to 990.
*
* @param scope the scope
*/
public LanguageSelector(String scope) {
this(Channel.SELF, scope);
}
/**
* Creates a new language selector component with its channel set
* to the given channel and the scope to "/". The handler's priority
* is set to 990.
*
* @param componentChannel the component channel
*/
public LanguageSelector(Channel componentChannel) {
this(componentChannel, "/");
}
/**
* Creates a new language selector component with its channel set
* to the given channel and the scope to the given scope. The
* handler's priority is set to 990.
*
* @param componentChannel the component channel
* @param scope the scope
*/
@SuppressWarnings("PMD.AvoidLiteralsInIfCondition")
public LanguageSelector(Channel componentChannel, String scope) {
this(componentChannel, scope, 990);
}
/**
* Creates a new language selector component with its channel set
* to the given channel and the scope to the given scope. The
* handler's priority is set to the given value.
*
* @param componentChannel the component channel
* @param scope the scope
* @param priority the priority
*/
@SuppressWarnings("PMD.AvoidLiteralsInIfCondition")
public LanguageSelector(Channel componentChannel, String scope,
int priority) {
super(componentChannel);
if ("/".equals(scope) || !scope.endsWith("/")) {
path = scope;
} else {
path = scope.substring(0, scope.length() - 1);
}
String pattern;
if ("/".equals(path)) {
pattern = "/**";
} else {
pattern = path + "," + path + "/**";
}
RequestHandler.Evaluator.add(this, "onRequest", pattern, priority);
}
/**
* Sets the name of the cookie used to store the locale.
*
* @param cookieName the cookie name to use
* @return the locale selector for easy chaining
*/
public LanguageSelector setCookieName(String cookieName) {
this.cookieName = cookieName;
return this;
}
/**
* Returns the cookie name. Defaults to the class name.
*
* @return the cookie name
*/
public String cookieName() {
return cookieName;
}
/**
* Sets the max age of the cookie used to store the preferences.
* Defaults to one year.
*
* @param maxAge the max age
* @return the language selector
* @see HttpCookie#setMaxAge(long)
*/
public LanguageSelector setCookieMaxAge(Duration maxAge) {
cookieMaxAge = maxAge.toSeconds();
return this;
}
/**
* Returns the max age of the cookie used to store the preferences.
*
* @return the duration
*/
public Duration cookieMaxAge() {
return Duration.ofSeconds(cookieMaxAge);
}
/**
* Sets the same site attribute for the locale cookie defaults to
* `Lax`.
*
* @param attribute the attribute
* @return the language selector
*/
public LanguageSelector setSameSiteAttribute(SameSiteAttribute attribute) {
cookieSameSite = attribute;
return this;
}
/**
* Returns the value of the same site attribute.
*
* @return the same site attribute
*/
public SameSiteAttribute sameSiteAttribute() {
return cookieSameSite;
}
/**
* Associates the event with a {@link Selection} object
* using `Selection.class` as association identifier.
* Does nothing if the request has already been fulfilled.
*
* @param event the event
*/
@SuppressWarnings({ "PMD.DataflowAnomalyAnalysis", "PMD.EmptyCatchBlock" })
@RequestHandler(dynamic = true)
public void onRequest(Request.In event) {
if (event.fulfilled()) {
return;
}
@SuppressWarnings("PMD.AccessorClassGeneration")
final Selection selection
= (Selection) Session.from(event).computeIfAbsent(Selection.class,
newKey -> new Selection(cookieName, path, cookieMaxAge,
cookieSameSite));
selection.setCurrentEvent(event);
event.setAssociated(Selection.class, selection);
if (selection.isExplicitlySet()) {
return;
}
// Try to get locale from cookies
final HttpRequest request = event.httpRequest();
Optional localeNames = request.findValue(
HttpField.COOKIE, Converters.COOKIE_LIST)
.flatMap(cookieList -> cookieList.valueForName(cookieName));
if (localeNames.isPresent()) {
try {
List cookieLocales = LOCALE_LIST
.fromFieldValue(localeNames.get());
if (!cookieLocales.isEmpty()) {
Collections.reverse(cookieLocales);
cookieLocales.stream().forEach(selection::prefer);
return;
}
} catch (ParseException e) {
// Unusable
}
}
// Last resport: Accept-Language header field
Optional>> accepted = request.findValue(
HttpField.ACCEPT_LANGUAGE, Converters.LANGUAGE_LIST);
if (accepted.isPresent()) {
Locale[] locales = accepted.get().stream()
.sorted(ParameterizedValue.WEIGHT_COMPARATOR)
.map(ParameterizedValue::value).toArray(Locale[]::new);
selection.updateFallbacks(locales);
}
}
/**
* Handles a procotol switch by associating the language selection
* with the channel.
*
* @param event the event
* @param channel the channel
*/
@Handler(priority = 1000)
public void onProtocolSwitchAccepted(
ProtocolSwitchAccepted event, IOSubchannel channel) {
event.requestEvent().associated(Selection.class)
.ifPresent(
selection -> channel.setAssociated(Selection.class, selection));
}
/**
* Convenience method to retrieve a locale from an associator.
*
* @param assoc the associator
* @return the locale
*/
public static Locale associatedLocale(Associator assoc) {
return assoc.associated(Selection.class)
.map(sel -> sel.get()[0]).orElse(Locale.getDefault());
}
/**
* Represents a locale selection.
*/
@SuppressWarnings({ "serial", "PMD.DataflowAnomalyAnalysis" })
public static final class Selection implements Serializable {
private transient WeakReference currentEvent;
private final String cookieName;
private final String cookiePath;
private final long cookieMaxAge;
private final SameSiteAttribute cookieSameSite;
private boolean explicitlySet;
private Locale[] locales;
@ConstructorProperties({ "cookieName", "cookiePath", "cookieMaxAge",
"cookieSameSite" })
private Selection(String cookieName, String cookiePath,
long cookieMaxAge, SameSiteAttribute cookieSameSite) {
this.cookieName = cookieName;
this.cookiePath = cookiePath;
this.cookieMaxAge = cookieMaxAge;
this.cookieSameSite = cookieSameSite;
this.currentEvent = new WeakReference<>(null);
explicitlySet = false;
locales = new Locale[] { Locale.getDefault() };
}
/**
* Gets the cookie name.
*
* @return the cookieName
*/
public String getCookieName() {
return cookieName;
}
/**
* Gets the cookie path.
*
* @return the cookiePath
*/
public String getCookiePath() {
return cookiePath;
}
/**
* Gets the cookie max age.
*
* @return the cookie max age
*/
public long getCookieMaxAge() {
return cookieMaxAge;
}
/**
* Gets the cookie same site.
*
* @return the cookie same site
*/
public SameSiteAttribute getCookieSameSite() {
return cookieSameSite;
}
/**
* Checks if is explicitly set.
*
* @return the explicitlySet
*/
public boolean isExplicitlySet() {
return explicitlySet;
}
/**
*
* @param locales
*/
@SuppressWarnings("PMD.UseVarargs")
private void updateFallbacks(Locale[] locales) {
if (explicitlySet) {
return;
}
this.locales = Arrays.copyOf(locales, locales.length);
}
/**
* @param currentEvent the currentEvent to set
*/
private Selection setCurrentEvent(Request.In currentEvent) {
this.currentEvent = new WeakReference<>(currentEvent);
return this;
}
/**
* Return the current locale.
*
* @return the value;
*/
public Locale[] get() {
return Arrays.copyOf(locales, locales.length);
}
/**
* Updates the current locale.
*
* @param locale the locale
* @return the selection for easy chaining
*/
public Selection prefer(Locale locale) {
explicitlySet = true;
List list = new ArrayList<>(Arrays.asList(locales));
list.remove(locale);
list.add(0, locale);
this.locales = list.toArray(new Locale[0]);
Request.In req = currentEvent.get();
if (req != null) {
req.httpRequest().response().ifPresent(resp -> {
resp.computeIfAbsent(HttpField.SET_COOKIE,
() -> new CookieList(cookieSameSite))
.value().add(getCookie());
});
}
return this;
}
/**
* Returns a cookie that reflects the current selection.
*
* @return the cookie
*/
public HttpCookie getCookie() {
HttpCookie localesCookie = new HttpCookie(cookieName,
LOCALE_LIST.asFieldValue(Arrays.asList(locales)));
localesCookie.setPath(cookiePath);
localesCookie.setMaxAge(cookieMaxAge);
return localesCookie;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
StringBuilder builder = new StringBuilder(50);
builder.append("Selection [");
if (locales != null) {
builder.append("locales=").append(Arrays.toString(locales))
.append(", ");
}
builder.append("explicitlySet=").append(explicitlySet).append(']');
return builder.toString();
}
}
}