具有自定義多對多關系，帶有參數的關系表的Grails

Question

我有以下域：評論，Secuser和評級。

我希望每個評論可由SecUser +1或-1評分一次。 在相關評論（針對領域討論）的視圖中，我希望有一個按鈕可以向上或向下投票並刷新視圖。 我到目前為止的代碼：注釋視圖：

<tbody>
    <g:each in="${comments}" var="comm">
        <tr>
            <td>${comm.comment}</td>
            <td>${comm.commentBy}</td>
            <td><g:formatDate format="dd.MM.yyyy HH:mm" date="${comm.createDate}"/> </td>
            <td><button type="button" class="btn btn-default btn-lg" onclick="${remoteFunction(action: 'ratePositiveComment', update: 'content', params:[commentID:"${comm.id}"])}"><span class="glyphicon glyphicon-thumbs-up" aria-hidden="false" style="float:right">${comm.numberPositiveRatings}</span></button>
                &nbsp;
                <button type="button" class="btn btn-default btn-lg" onclick="${remoteFunction(action: 'rateNegativeComment', update: 'content', params:[commentID:"${comm.id}"])}"><span class="glyphicon glyphicon-thumbs-down" aria-hidden="false" onclick="addRating(-1, ${comm.id})" style="float:right">${comm.numberNegativeRatings}</span></button>
            </td>
        </tr>
    </g:each>
</tbody>

評論控制器：

class Comments {
    static belongsTo = Discussion
    Discussion discussion
    SecUser commentBy
    String comment
    Date createDate = new Date()
    static hasMany = [commRatings : Rating]

    public long getNumberPositiveRatings() {
    return  Rating.countByCommentRatedAndRate(this, 1);
    }

    public long getNumberNegativeRatings() {
        return  Rating.countByCommentRatedAndRate(this, -1);
    }

    List raters() {
        return commRatings.collect{it.ratingUser}
    }

    List addToPosRatingUser(SecUser user) {
        Rating.positiveRating(user, this)
        //return raters()
    }

    List addToNegRatingUser(SecUser user) {
        Rating.negativeRating(user, this)
       // return raters()
    }

評級域：

class Rating {
    static belongsTo = Comments
    int rate
    SecUser ratingUser
    Comments commentRated

    static Rating positiveRating(ratingUser, commentRated) {
        def m = Rating.findByRatingUserAndCommentRated(ratingUser, commentRated)
        if (!m) {
            m = new Rating()
            ratingUser?.addToRating(m)
            commentRated?.addToRating(m)
            m.rate = 1;
            m.save()
        }
        return m
    }

    static Rating negativeRating(ratingUser, commentRated) {
        def m = Rating.findByRatingUserAndCommentRated(ratingUser, commentRated)
        if (!m) {
            m = new Rating()
            ratingUser?.addToRating(m)
            commentRated?.addToRating(m)
            m.rate = -1;
            m.save()
        }
        return m
    }
}

在域SecUser（Spring安全插件）中，我添加了：

class SecUser {

    transient springSecurityService

    String username
    String password
    String userEmail
    boolean enabled = true
    boolean accountExpired
    boolean accountLocked
    boolean passwordExpired

    static hasMany = [ratings:Rating]

    List ratedComments() {
        return ratings.collect{it.commentRated}
    }

    List addPosCommentRating(Comments comm) {
        Rating.positiveRating(this, comm)
        return ratedComments()
    }

    List addNegCommentRating(Comments comm) {
        Rating.negativeRating(this, comm)
        return ratedComments()
    }

CommentsController是腳手架，唯一添加的功能是：

def ratePositiveComment() {
    def rater = SecUser.findById(springSecurityService.currentUser.id);
    if(rater!=null) {
        Comments comm = Comments.get(params.commentID);
        comm.addToPosRatingUser(rater);
        comm.save();
    }
}


def rateNegativeComment() {
    def rater = SecUser.findById(springSecurityService.currentUser.id);
    if(rater!=null) {
        Comments comm = Comments.get(params.commentID);
        comm.addToNegRatingUser(rater);
        comm.save();
    }
}

我得到的錯誤代碼是：

No signature of method: ForumProject.SecUser.addToRating() is applicable for argument types: (ForumProject.Rating) values: [ForumProject.Rating : (unsaved)]
Possible solutions: addToRatings(java.lang.Object). Stacktrace follows:
Message: No signature of method: ForumProject.SecUser.addToRating() is applicable for argument types: (ForumProject.Rating) values: [ForumProject.Rating : (unsaved)]
Possible solutions: addToRatings(java.lang.Object)

Answer 1

addTo （和removeFrom ）方法是從hasMany映射中的名稱派生的。 如果您已經聲明

static hasMany = [rating:Rating]

那么addTo方法將是addToRating並且您的代碼將是正確的。 現在，您只需要更改對addToRatings的調用即可。

ps這很不好：

def rater = SecUser.findById(springSecurityService.currentUser.id);

springSecurityService.currentUser已經是您想要的，用於登錄時用於創建Authentication的SecUser ，它是通過查詢而不是從某些緩存從數據庫中檢索的。 但是您在獲得id后將其丟棄，因此可以使用效率低下的動態查找器再次加載它。 始終使用get而不是findById 。 所以你的代碼應該只是

def rater = springSecurityService.currentUser