如何重写ApplicationTagLib的标准行为＃createLink和g：link？ [英] How to override standard behavior of ApplicationTagLib#createLink and g:link?
问题描述
g：createLink 和 g：链接在很多页面上。 最近我决定在url映射中做大的改动 - 介绍前面的路径元素。
- 目前我有：
/ $ controller / $ action？/ $ id？ -
$ <$> $ $ $ $ $ $ $ $ $ $ $ $ $ b
很容易更改urlMappings，但我无法弄清楚如何轻松更改链接在应用程序中的构建方式。
基本上，我不想浏览每个网页并更改链接。但想在一个地方做到这一点。
问题
如何覆盖ApplicationTagLib＃createLink功能，以便grails将使用此实现需要更改使用这个标签（或函数）的页面？
任何帮助大大appriciated！
我无法用OOP解决这个问题。我的意思是我无法找到如何覆盖闭包。我尝试了几种方法，但没有成功。并且表示您无法覆盖关闭，您只能将其替换为新的（请纠正我，如果我错了）。
但是（！）我能够通过复制粘贴ApplicationTagLib的源代码来解决任务#createLink方法。
我认为这是一个残酷的解决方案，但经过8个小时与这个简单的任务作斗争 - 这是可以接受的。
因此，最后我需要做的是 - 定义这个类，grails会立即使用它进行链接生成（对于所有视图，不需要更改它们的代码）：
import java .text.SimpleDateFormat;
导入groovy.time。*;
import java.text。*;
导入org.codehaus.groovy.grails.commons.GrailsControllerClass
导入org.codehaus.groovy.grails.plugins.web.taglib.ApplicationTagLib;
import org.codehaus.groovy.grails.web.mapping.UrlCreator
import org.codehaus.groovy.grails.commons.ControllerArtefactHandler
import org.springframework.web.context.request.RequestContextHolder
类OverrideTagLib扩展ApplicationTagLib {
def createLink = {attrs - >
//获取regionId参数的值
def regionId = regionIdFinderService.currentRegionId
// add cutsom regionId参数
if（attrs）{
if（ attrs.params）
attrs.params.put（regionId，regionId）;
else {
attrs.params = [regionId：regionId];
$ process
def writer = getOut（）
//更喜欢URI属性
if（attrs.uri） {
作家<< handleAbsolute（attrs）
writer<< attrs.uri.toString（）
}
else {
//偏好URL属性
def urlAttrs = attrs
if（attrs.url instanceof Map）{
urlAttrs = attrs.remove（'url'）。clone（）
}
else if（attrs.url）{
urlAttrs = attrs.remove（'url'）。toString （）
}
if（urlAttrs instanceof String）{
if（useJsessionId）{
writer<< response.encodeURL（urlAttrs）
}
else {
writer<< urlAttrs
}
}
else {
def controller = urlAttrs.containsKey（controller）？ urlAttrs.remove（controller）？。toString（）：controllerName
def action = urlAttrs.remove（action）?. toString（）
if（controller&！action）{
GrailsControllerClass controllerClass = grailsApplication.getArtefactByLogicalPropertyName（ControllerArtefactHandler.TYPE，controller）
String defaultAction = controllerClass？.getDefaultAction（）
if（controllerClass？.hasProperty（defaultAction））{
action = defaultAction
def id = urlAttrs.remove（id）
def frag = urlAttrs.remove（'fragment'）?. toString（）
def params = urlAttrs.params&& urlAttrs.params instanceof Map？ urlAttrs.remove（'params'）：[：]
def mappingName = urlAttrs.remove（'mapping'）
if（mappingName！= null）{
params.mappingName = mappingName
if（request ['flowExecutionKey']）{
params。execution= request ['flowExecutionKey']
}
if（urlAttrs。事件）{
params。_ eventId= urlAttrs.remove（'event'）
}
def url
if（id！= null）params.id = id
def urlMappings = applicationContext.getBean（grailsUrlMappingsHolder）
UrlCreator mapping = urlMappings.getReverseMapping（控制器，动作，参数）
//不能在绝对链接中使用jsessionid
if（useJsessionId&！attrs.absolute）{
url = mapping.create URL（控制器，动作，参数，request.characterEncoding，frag）
def base = attrs.remove（'base'）
if（base）writer< base
writer<< response.encodeURL（url）
}
else {
url = mapping.createRelativeURL（controller，action，params，request.characterEncoding，frag）
writer<< handleAbsolute（attrs）
writer<<网址
}
}
}
}
}
Background:
I have grails 1.3.7 application which uses g:createLink and g:link on many pages.
Recently I decided to make big change in url mappings - introduce preceding path element.
- Currently I have:
/$controller/$action?/$id? - But want to have:
/$regionId/$controller/$action?/$id?
It was easy to change urlMappings, but I can't figure out how to easily change the behavior how links are built throught the application.
Basically, I don't want to go through each page and change links. But want to do this in one place.
Question How to override ApplicationTagLib#createLink functionality so grails will use this implementation without the need of changes pages which use this tag (or function)?
Any help greatly appriciated!
I was unable to solve this problem in terms of OOP. I mean I can't find way how to override closure. I tried several approaches, but with no success. And documentation says that you can't override closure, you can only replace it with new implementation (please correct me if I wrong).
But (!) I was able to solve task by copy-pasting source code of ApplicationTagLib#createLink method. I think this is brutal solution, but after 8 hours of fighting with this simple task - it's acceptable.
So finally all I need to do - is define this class, grails will immediately use it for link generation (for all views, no need to change their code):
import java.text.SimpleDateFormat;
import groovy.time.*;
import java.text.*;
import org.codehaus.groovy.grails.commons.GrailsControllerClass
import org.codehaus.groovy.grails.plugins.web.taglib.ApplicationTagLib;
import org.codehaus.groovy.grails.web.mapping.UrlCreator
import org.codehaus.groovy.grails.commons.ControllerArtefactHandler
import org.springframework.web.context.request.RequestContextHolder
class OverrideTagLib extends ApplicationTagLib {
def createLink = { attrs ->
// get value for regionId parameter
def regionId = regionIdFinderService.currentRegionId
// add cutsom regionId parameter
if (attrs) {
if (attrs.params)
attrs.params.put("regionId", regionId);
else {
attrs.params = ["regionId":regionId];
}
}
// process
def writer = getOut()
// prefer URI attribute
if (attrs.uri) {
writer << handleAbsolute(attrs)
writer << attrs.uri.toString()
}
else {
// prefer a URL attribute
def urlAttrs = attrs
if (attrs.url instanceof Map) {
urlAttrs = attrs.remove('url').clone()
}
else if (attrs.url) {
urlAttrs = attrs.remove('url').toString()
}
if (urlAttrs instanceof String) {
if (useJsessionId) {
writer << response.encodeURL(urlAttrs)
}
else {
writer << urlAttrs
}
}
else {
def controller = urlAttrs.containsKey("controller") ? urlAttrs.remove("controller")?.toString() : controllerName
def action = urlAttrs.remove("action")?.toString()
if (controller && !action) {
GrailsControllerClass controllerClass = grailsApplication.getArtefactByLogicalPropertyName(ControllerArtefactHandler.TYPE, controller)
String defaultAction = controllerClass?.getDefaultAction()
if (controllerClass?.hasProperty(defaultAction)) {
action = defaultAction
}
}
def id = urlAttrs.remove("id")
def frag = urlAttrs.remove('fragment')?.toString()
def params = urlAttrs.params && urlAttrs.params instanceof Map ? urlAttrs.remove('params') : [:]
def mappingName = urlAttrs.remove('mapping')
if (mappingName != null) {
params.mappingName = mappingName
}
if (request['flowExecutionKey']) {
params."execution" = request['flowExecutionKey']
}
if (urlAttrs.event) {
params."_eventId" = urlAttrs.remove('event')
}
def url
if (id != null) params.id = id
def urlMappings = applicationContext.getBean("grailsUrlMappingsHolder")
UrlCreator mapping = urlMappings.getReverseMapping(controller,action,params)
// cannot use jsessionid with absolute links
if (useJsessionId && !attrs.absolute) {
url = mapping.createURL(controller, action, params, request.characterEncoding, frag)
def base = attrs.remove('base')
if (base) writer << base
writer << response.encodeURL(url)
}
else {
url = mapping.createRelativeURL(controller, action, params, request.characterEncoding, frag)
writer << handleAbsolute(attrs)
writer << url
}
}
}
}
}
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