如何在Primefaces lazy DataTable上禁用排序？

Question

我有一个带有懒惰数据模型和分页的datatable。当我单击“搜索”按钮时，我想禁用默认排序，当我单击“显示”按钮时，我想再次启用默认排序。所以我没有把“sortby”放在我的xhtml文件中，而是在我的backing bean中动态地设置它。

一切都正常工作，直到我点击标题在降序和升序之间翻转排序顺序。这意味着“搜索”按钮将禁用排序，而“显示”按钮将正确启用排序，如果我没有单击标题。但是，当我单击标题，然后单击“搜索”按钮时，在LazyDataModel的加载功能中，参数sortfield的值为“date”，datatable将按日期排序，尽管“date”列显然没有着色！！

这是我的DataTable：

<h:form id="contents-form">
...
    <p:dataTable id="tbl" widgetVar="tbl" var="msg" value="#{homeController.messagesModel}" lazy="true"
                 currentPageReportTemplate="سطر {startRecord}-{endRecord} از {totalRecords}"
                 paginatorTemplate="{CurrentPageReport}  {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}"
                 paginator="true" rows="10" rowsPerPageTemplate="5,10,15"
                 emptyMessage="هیچ پیامکی وجود ندارد."
                 selection="#{homeController.selectedMessages}" rowSelectMode="checkbox"
                 rowKey="#{msg.id}" filteredValue="#{homeController.filteredMessage}"
                 editable="true" editMode="cell"
                 style="width:100%" dir="rtl">

        <f:facet name="header">
            <p:commandButton value="خروجی" action="#{homeController.prepareExport}" icon="fa fa-save"
                             update="export-dlg-box" oncomplete="PF('exportDlgBox').show()"/>
            <p:commandButton value="واژگان" action="#{homeController.showListTermsChart}"
                             icon="fa fa-bar-chart" update="contents-form chart-form msgs"
                             oncomplete="PF('chartDlgBox').show()"/>
        </f:facet>

        <p:ajax event="cellEdit" listener="#{homeController.onCellEdit}" oncomplete="updateDescFilter()"/>

        <p:column selectionMode="multiple" style="width:16px;text-align:center"/>

        <p:column headerText="فرستنده" style="width:100px" filterBy="#{msg.sender.number}"
                  sortBy="#{msg.sender.number}">
            <p:commandLink action="#{homeController.setPhoneNumToShow(msg.sender)}" update="phone-form"
                           oncomplete="PF('phoneDlgBox').show()" styleClass="simple-command-link">
                <h:outputText value="#{msg.sender.number}"/>
            </p:commandLink>
        </p:column>

        <p:column headerText="گیرنده" style="width:100px" filterBy="#{msg.receiver.number}"
                  sortBy="#{msg.receiver.number}">
            <p:commandLink action="#{homeController.setPhoneNumToShow(msg.receiver)}" update="phone-form"
                           oncomplete="PF('phoneDlgBox').show()" styleClass="simple-command-link">
                <h:outputText value="#{msg.receiver.number}"/>
            </p:commandLink>
        </p:column>

        <p:column headerText="متن" sortBy="#{msg.text}">
            <h:outputText value="#{msg.getTrimmedText()}"/>
        </p:column>

        <p:column headerText="زمان" style="width:100px" filterBy="#{msg.date}" sortBy="#{msg.date}">
            <f:facet name="filter">
                <p:calendar pattern="yyyy-MM-dd">
                    <p:ajax event="dateSelect" oncomplete="PF('tbl').filter()" update="tbl"/>
                </p:calendar>
            </f:facet>
            <h:outputText value="#{msg.getJalaliDate()}"/>
        </p:column>

        <p:column headerText="منبع" style="width:70px" filterBy="#{msg.source}" sortBy="#{msg.source}">
            <f:facet name="filter">
                <p:selectOneMenu onchange="PF('tbl').filter()" style="width:30px; direction:ltr">
                    <f:selectItem itemLabel="همه" itemValue="#{null}" noSelectionOption="true"/>
                    <f:selectItems value="#{homeController.sources}" var="source"
                                   itemValue="#{source}" itemLabel="#{source}"/>
                </p:selectOneMenu>
            </f:facet>
            <h:outputText value="#{msg.source}"/>
        </p:column>

        <p:column headerText="توضیح" style="width:70px" filterBy="#{msg.description}"
                  sortBy="#{msg.description}">
            <f:facet name="filter">
                <p:selectOneMenu id="desc-filter-select" onchange="PF('tbl').filter()"
                                 style="width:30px; direction:ltr">
                    <f:selectItem itemLabel="همه" itemValue="#{null}" noSelectionOption="true"/>
                    <f:selectItems value="#{homeController.descriptions}" var="desc"
                                   itemValue="#{desc}" itemLabel="#{desc}"/>
                </p:selectOneMenu>
            </f:facet>
            <p:cellEditor>
                <f:facet name="output"><h:outputText value="#{msg.description}"/></f:facet>
                <f:facet name="input"> <p:inputText id="desc-input" value="#{msg.description}"
                                                    style="width:85%"/></f:facet>
            </p:cellEditor>
        </p:column>

        <p:column headerText="جزئیات" style="width:40px">
            <p:commandLink action="#{homeController.setMessageToShow(msg)}" ajax="true"
                           update="img-dlg-box" oncomplete="PF('imgDlgBox').show()">
                <i class="fa fa-blue fa-desktop"/>
            </p:commandLink>
        </p:column>

        <p:column headerText="مشاهده گفتگو" style="width:40px">
            <p:commandLink action="#{homeController.showConversation(msg.sender, msg.receiver)}"
                           ajax="true" update="conv-dlg-box" oncomplete="PF('convDlgBox').show()">
                <i class="fa fa-blue fa-wechat"/>
            </p:commandLink>
        </p:column>
    </p:dataTable>
</h:form>

我的“搜索”按钮：

<p:commandButton value="جست‌وجو" action="#{homeController.search}" update=":contents-form:tbl msgs"
                                     icon="fa fa-search"/>

我的“显示”按钮：

<p:commandButton value="نمایش" icon="fa fa-desktop" action="#{homeController.loadArchive}"
                 update="contents-form msgs"/>

public void search() {
    if (this.selectedArchive == null) {
        FacesContext.getCurrentInstance().addMessage(null,
                new FacesMessage(FacesMessage.SEVERITY_ERROR, "خطا!", "لطفا یک مجموعه را انتخاب کنید"));
        return;
    }

    if ((this.textQuery != null && !this.textQuery.equals(""))
            || (this.selectedNodes != null && this.selectedNodes.length > 0)) {
        logger.info(String.format("searching '%s' in archive %d ...", this.textQuery, this.selectedArchive.getId()));
        List<String> selectedWords = this.getSelectedWords(this.selectedNodes);
        searchText(this.textQuery, selectedWords);
    } else {
        FacesContext.getCurrentInstance().addMessage(null,
                new FacesMessage(FacesMessage.SEVERITY_ERROR, "خطا!", "برای جست‌وجو هیچ متنی وارد نشده و هیچ واژه‌ای انتخاب نشده است."));
        return;
    }

    extractChoices();

    // Disable default sorting:
    DataTable table = (DataTable) FacesContext.getCurrentInstance().getViewRoot().findComponent(":contents-form:tbl");
    table.setValueExpression("sortBy", null);
    table.setValueExpression("sortOrder", null);
}

public void loadArchive() {
    if (this.selectedArchive == null) {
        FacesContext.getCurrentInstance().addMessage(null,
                new FacesMessage(FacesMessage.SEVERITY_ERROR, "خطا!", "لطفا یک مجموعه را انتخاب کنید"));
        return;
    }
    this.messagesModel = new LazyMessageModel(this.selectedArchive, true, this.messageService);

    extractChoices();

    // Enable default sorting:
    FacesContext context = FacesContext.getCurrentInstance();
    ExpressionFactory ef = context.getApplication().getExpressionFactory();
    DataTable table = (DataTable) context.getViewRoot().findComponent(":contents-form:tbl");
    ValueExpression sortVe = ef.createValueExpression(context.getELContext(), "#{msg.date}", Message.class);
    table.setValueExpression("sortBy", sortVe);
    table.setSortOrder("descending");

    logger.info(String.format("archive %d loaded", (this.selectedArchive.getId())));
}

null

Answer 1

我终于找到了一个干净的解决办法！单击“Search”按钮后，除了设置sortbynull外，还必须重置表：

public void search() {
    // Do something ...
    DataTable table = (DataTable) FacesContext.getCurrentInstance().getViewRoot().findComponent(":contents-form:tbl");
    table.reset();
    table.setValueExpression("sortBy", null);
}