是否可以查看修改后的实体上的特定属性是否发生了变化？ [英] Is it possible to see if a specific property changed on a modified entity?

问题描述

保存某个实体时，如果该实体的批准属性已更改，我想发送通知电子邮件。

When saving a certain entity I want to send a notification email if the Approved property of this entity has changed.

            if (changedEntity.Entity is Option)
            {
                // Pseudo
                if changedEntity.Entity.Approved changed {
                     send notification()
                }
            }

有某种方法可以做到这一点吗？还是可以将 CurrentValues 与 OriginalValues 进行比较？

Is there a certain way to do this? Or can it be done by comparing the CurrentValues against the OriginalValues?

推荐答案

如果知道要监视的特定实体，则可以使用 EntityAspect.propertyChanged 事件（请参阅： http://breeze.github.io/doc-js/api-docs /classes/EntityAspect.html#event_propertyChanged ）像这样：

If you know the specific entity that you want to 'watch', you can use the EntityAspect.propertyChanged event (see: http://breeze.github.io/doc-js/api-docs/classes/EntityAspect.html#event_propertyChanged) like this:

// assume order is an order entity attached to an EntityManager.
myEntity.entityAspect.propertyChanged.subscribe(function(propertyChangedArgs) {
    // this code will be executed anytime a property value changes on the 'myEntity' entity.
   if ( propertyChangedArgs.propertyName === "Approved") {
      // perform your logic here.
   }
});

或者，如果您想观看每个实体的特定属性，则可以使用 EntityManger.entityChanged 事件（请参阅： http://breeze.github.io/doc-js/api-docs/classes/EntityManager.html#event_entityChanged ）

Or if you want to watch a specific property on every entity, you can perform a similar test using the EntityManger.entityChanged event (see: http://breeze.github.io/doc-js/api-docs/classes/EntityManager.html#event_entityChanged)

  myEntityManager.entityChanged.subscribe(function (args) {
    // entity will be the entity that was just changed;
    var entity = args.entity;
    // entityAction will be the type of change that occured.
    var entityAction = args.entityAction;
    if (entityAction == breeze.EntityAction.PropertyChange) {
       var propChangArgs = args.args;
       if (propChangeArgs.propertyName === "Approved") {
          // perform your logic here  
       }
    }

  });

更多详细信息可以在这里找到： http://breeze.github.io/doc-js/lap-changetracking.html

More detail can be found here: http://breeze.github.io/doc-js/lap-changetracking.html

这篇关于是否可以查看修改后的实体上的特定属性是否发生了变化？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！