我的问题是:我想创建一个grails域实例,定义它拥有的另一个域的’Many’实例.我在
Google Code Project中有实际的来源,但下面应该说明问题.
- class Person {
- String name
- static hasMany[skills:Skill]
- static constraints = {
- id (visible:false)
- skills (nullable:false,blank:false)
- }
- }
- class Skill {
- String name
- String description
- static constraints = {
- id (visible:false)
- name (nullable:false,blank:false)
- description (nullable:false,blank:false)
- }
- }
如果您为两个控制器使用此模型和def脚手架,那么您最终会得到一个不起作用的表单;
我自己试图让这个工作计算出技能为复选框,看起来像这样;
但是当我拯救志愿者时,技能无效!
- def save = {
- log.info "Saving: " + params.toString()
- def skills = params.skills
- log.info "Skills: " + skills
- def volunteerInstance = new Volunteer(params)
- log.info volunteerInstance
- if (volunteerInstance.save(flush: true)) {
- flash.message = "${message(code: 'default.created.message',args: [message(code: 'volunteer.label',default: 'Volunteer'),volunteerInstance.id])}"
- redirect(action: "show",id: volunteerInstance.id)
- log.info volunteerInstance
- }
- else {
- render(view: "create",model: [volunteerInstance: volunteerInstance])
- }
- }
- 2010-05-10 21:06:41,494 [http-8080-3] INFO bumbumtrain.VolunteerController - Saving: ["skills":["1","2"],"name":"Ian","_skills":["",""],"create":"Create","action":"save","controller":"volunteer"]
- 2010-05-10 21:06:41,495 [http-8080-3] INFO bumbumtrain.VolunteerController - Skills: [1,2]
- 2010-05-10 21:06:41,508 [http-8080-3] INFO bumbumtrain.VolunteerController - Volunteer[ id: null | Name: Ian | Skills [Skill[ id: 1 | Name: Carpenter ],Skill[ id: 2 | Name: Sound Engineer ] ]]
请注意,在最终日志行中,已选择了正确的技能,并且这些技能是对象实例的一部分.当志愿者被保存时,“技能”被忽略并且没有被提交到数据库,尽管内存版本明确地创建了项目.是不是可以在施工时通过技能?这一定有办法吗?我需要一个表单来允许一个人注册,但我想规范化数据,以便我以后可以添加更多技能.
如果您认为这应该“正常工作”,那么指向实际示例的链接将非常棒.
如果我使用HTML Select那么它工作正常!如下面的Make页面;
- <tr class="prop">
- <td valign="top" class="name">
- <label for="skills"><g:message code="volunteer.skills.label" default="Skills" /></label>
- </td>
- <td valign="top" class="value ${hasErrors(bean: volunteerInstance,field: 'skills','errors')}">
- <g:select name="skills" from="${uk.co.bumbumtrain.Skill.list()}" multiple="yes" optionKey="id" size="5" value="${volunteerInstance?.skills}" />
- </td>
- </tr>
但我需要它来处理像这样的复选框;
- <tr class="prop">
- <td valign="top" class="name">
- <label for="skills"><g:message code="volunteer.skills.label" default="Skills" /></label>
- </td>
- <td valign="top" class="value ${hasErrors(bean: volunteerInstance,'errors')}">
- <g:each in="${skillInstanceList}" status="i" var="skillInstance">
- <label for="${skillInstance?.name}"><g:message code="${skillInstance?.name}.label" default="${skillInstance?.name}" /></label>
- <g:checkBox name="skills" value="${skillInstance?.id.toString()}"/>
- </g:each>
- </td>
- </tr>
日志输出完全相同!使用两种形式的格式,可以使用“技能”变量中正确引用的技能创建志愿者实例.保存时,后者失败并显示空引用异常,如此问题顶部所示.
希望这是有道理的,提前谢谢!
GAV
解决方法
替换你的create.gsp< g:复选框...>代码:
- <g:checkBox name="skill_${skillInstance.id}"/>
然后在你的控制器的保存动作中,替换def志愿者实例=新的志愿者(params):
- def volunteerInstance = new Volunteer(name: params.name)
- params.each {
- if (it.key.startsWith("skill_"))
- volunteerInstance.skills << Skill.get((it.key - "skill_") as Integer)
- }
应该管用. (代码未经测试)