Question

我有一个内容部分，提供开始时间戳和结束时间戳选项。这两个字段用于定义应显示内容项的时间段。

我现在很难实现跳过方法，而当时间段不跨越当前时间时，不应显示/跳过内容项。

挖掘源代码并尝试为我的方法找到一个入口点，产生了以下内容处理程序

public class SkipContentHandler : Orchard.ContentManagement.Handlers.ContentHandler
{
  protected override void BuildDisplayShape(Orchard.ContentManagement.Handlers.BuildDisplayContext aContext)
  {
    if (...) // my condition to process only content shapes which need to be skipped
    {
      aContext.Shape = null; // return null shape to skip it
    }
  }
}

这有效，但有几种副作用

我必须更改BuildDisplayContext的源代码，因为Shape通常是只读的
列表形状在包含内容部分的内容项时可能会显示错误的寻呼机，因为Count()中的ContainerPartDriver.Display()来电已在BuildDisplay()之前执行
调用被跳过的内容项的网址会导致异常，因为View(null)很神奇

那么，这里的正确方法是什么，或者是否有任何模块可以完成这项工作？我找不到一个。

Answer 1

这是一项非常复杂的任务。实现正确跳过显示项目需要几个步骤：

正确创建零件

这里有一些陷阱，因为在进行添加零件视图的任务时，可能会使用Orchards日期时间编辑器与DateTime属性相关联。但这会带来很多额外的问题，但这些问题并没有真正与这个问题有关。

如果有人对如何使用Orchards日期时间编辑器感兴趣，那么我也可以发布此代码，但是现在它只会不必要地炸掉代码。

所以我们去，部分类......

public class ValidityPart : Orchard.ContentManagement.ContentPart<ValidityPartRecord>
{
  // public
    public System.DateTime? ValidFromUtc 
    { 
      get { return Retrieve(r => r.ValidFromUtc); }
      set { Store(r => r.ValidFromUtc, value); }
    }

    ...

    public System.DateTime? ValidTillUtc 
    { 
      get { return Retrieve(r => r.ValidTillUtc); }
      set { Store(r => r.ValidTillUtc, value); }
    }

    ...

    public bool IsContentItemValid()
    {
      var lUtcNow = System.DateTime.UtcNow;

      return (ValidFromUtc == null || ValidFromUtc.Value <= lUtcNow) && (ValidTillUtc == null || ValidTillUtc.Value >= lUtcNow);
    }

  ...
}

......和记录班......

public class ValidityPartRecord : Orchard.ContentManagement.Records.ContentPartRecord
{
  // valid from value as UTC to use Orchard convention (see CommonPart table) and to be compatible with projections
  // (date/time tokens work with UTC values, see https://github.com/OrchardCMS/Orchard/issues/6963 for a related issue)  
  public virtual System.DateTime? ValidFromUtc { get; set; }

  // valid from value as UTC to use Orchard convention (see CommonPart table) and to be compatible with projections
  // (date/time tokens work with UTC values, see https://github.com/OrchardCMS/Orchard/issues/6963 for a related issue)  
  public virtual System.DateTime? ValidTillUtc { get; set; }
}

创建自定义内容查询类

public class MyContentQuery : Orchard.ContentManagement.DefaultContentQuery
{ 
  // public
    public ContentQuery(Orchard.ContentManagement.IContentManager aContentManager, 
      Orchard.Data.ITransactionManager aTransactionManager, 
      Orchard.Caching.ICacheManager aCacheManager,
      Orchard.Caching.ISignals aSignals,
      Orchard.Data.IRepository<Orchard.ContentManagement.Records.ContentTypeRecord> aContentTypeRepository,
      Orchard.IWorkContextAccessor aWorkContextAccessor) 
        : base(aContentManager, aTransactionManager, aCacheManager, aSignals, aContentTypeRepository)
    {
      mWorkContextAccessor = aWorkContextAccessor;
    }

    protected override void BeforeExecuteQuery(NHibernate.ICriteria aContentItemVersionCriteria)
    {
      base.BeforeExecuteQuery(aContentItemVersionCriteria);

      // note:
      //  this method will be called each time a query for multiple items is going to be executed (e.g. content items of a container, layers, menus),
      //  this gives us the chance to add a validity criteria

      var lWorkContext = mWorkContextAccessor.GetContext();

      // exclude admin as content items should still be displayed / accessible when invalid as validity needs to be editable
      if (lWorkContext == null || !Orchard.UI.Admin.AdminFilter.IsApplied(lWorkContext.HttpContext.Request.RequestContext))
      {
        var lUtcNow = System.DateTime.UtcNow;

        // left outer join of ValidityPartRecord table as part is optional (not present on all content types)
        var ValidityPartRecordCriteria = aContentItemVersionCriteria.CreateCriteria(
          "ContentItemRecord.ValidityPartRecord", // string adopted from foreach loops in Orchard.ContentManagement.DefaultContentQuery.WithQueryHints()
          NHibernate.SqlCommand.JoinType.LeftOuterJoin 
        );

        // add validity criterion
        ValidityPartRecordCriteria.Add( 
          NHibernate.Criterion.Restrictions.And(
            NHibernate.Criterion.Restrictions.Or(
              NHibernate.Criterion.Restrictions.IsNull("ValidFromUtc"),
              NHibernate.Criterion.Restrictions.Le("ValidFromUtc", lUtcNow)
            ),
            NHibernate.Criterion.Restrictions.Or(
              NHibernate.Criterion.Restrictions.IsNull("ValidTillUtc"),
              NHibernate.Criterion.Restrictions.Ge("ValidTillUtc", lUtcNow)
            )
          )
        );
      }
    }

  // private
    Orchard.IWorkContextAccessor mWorkContextAccessor;
}

这实质上是将有效性部分字段的左连接添加到SQL查询（内容查询），并使用有效性条件扩展WHERE语句。

请注意，此步骤仅适用于描述以下问题的解决方案：https://github.com/OrchardCMS/Orchard/issues/6978

注册内容查询类

public class ContentModule : Autofac.Module
{
  protected override void Load(Autofac.ContainerBuilder aBuilder)
  {
    aBuilder.RegisterType<MyContentQuery>().As<Orchard.ContentManagement.IContentQuery>().InstancePerDependency();
  }
}

创建自定义内容管理器

public class ContentManager : Orchard.ContentManagement.DefaultContentManager
{
  // public
    public ContentManager(
      Autofac.IComponentContext aContext,
      Orchard.Data.IRepository<Orchard.ContentManagement.Records.ContentTypeRecord> aContentTypeRepository,
      Orchard.Data.IRepository<Orchard.ContentManagement.Records.ContentItemRecord> aContentItemRepository,
      Orchard.Data.IRepository<Orchard.ContentManagement.Records.ContentItemVersionRecord> aContentItemVersionRepository,
      Orchard.ContentManagement.MetaData.IContentDefinitionManager aContentDefinitionManager,
      Orchard.Caching.ICacheManager aCacheManager,
      System.Func<Orchard.ContentManagement.IContentManagerSession> aContentManagerSession,
      System.Lazy<Orchard.ContentManagement.IContentDisplay> aContentDisplay,
      System.Lazy<Orchard.Data.ITransactionManager> aTransactionManager,
      System.Lazy<System.Collections.Generic.IEnumerable<Orchard.ContentManagement.Handlers.IContentHandler>> aHandlers,
      System.Lazy<System.Collections.Generic.IEnumerable<Orchard.ContentManagement.IIdentityResolverSelector>> aIdentityResolverSelectors,
      System.Lazy<System.Collections.Generic.IEnumerable<Orchard.Data.Providers.ISqlStatementProvider>> aSqlStatementProviders,
      Orchard.Environment.Configuration.ShellSettings aShellSettings,
      Orchard.Caching.ISignals aSignals,
      Orchard.IWorkContextAccessor aWorkContextAccessor)
        : base(aContext, aContentTypeRepository, aContentItemRepository, aContentItemVersionRepository, aContentDefinitionManager, aCacheManager, aContentManagerSession,
            aContentDisplay, aTransactionManager, aHandlers, aIdentityResolverSelectors, aSqlStatementProviders, aShellSettings, aSignals)
    {
      mWorkContextAccessor = aWorkContextAccessor;
    }

    public override ContentItem Get(int aId, Orchard.ContentManagement.VersionOptions aOptions, Orchard.ContentManagement.QueryHints aHints)
    {
      var lResult = base.Get(aId, aOptions, aHints);

      if (lResult != null)
      {
        // note:
        //  the validity check is done here (after the query has been executed!) as changing base.GetManyImplementation() to 
        //  apply the validity critera directly to the query (like in ContentQuery) will not work due to a second attempt to retrieve the
        //  content item from IRepository<> (see base.GetManyImplementation(), comment "check in memory") when the query
        //  returns no data (and the query should not return data when the validity critera is false)
        //
        // http://stackoverflow.com/q/37841249/3936440

        var lWorkContext = mWorkContextAccessor.GetContext();

        // exclude admin as content items should still be displayed / accessible when invalid as validity needs to be editable
        if (lWorkContext == null || !Orchard.UI.Admin.AdminFilter.IsApplied(lWorkContext.HttpContext.Request.RequestContext))
        {
          var lValidityPart = lResult.As<ValidityPart>();
          if (lValidityPart != null)
          {
            if (lValidityPart.IsContentItemValid())
            {
              // content item is valid
            }
            else
            {
              // content item is not valid, return null (adopted from base.Get())

              lResult = null;
            }
          }
        }
      }

      return lResult;
    }

  // private
    Orchard.IWorkContextAccessor mWorkContextAccessor;
}

具有内容项时需要步骤2-4，而内容类型具有Container和Containable部分或甚至是单独处理/显示的内容项。在这里，您通常无法自定义幕后执行的内容查询。

如果使用Projection模块，则步骤2-4 不。但同样，这会带来一些其他问题，如本期所述：https://github.com/OrchardCMS/Orchard/issues/6979

如何跳过在Orchard CMS中显示内容项？

1 个答案: