关于以编程方式删除和应用 ADF 查看条件以查看对象的查询

问题描述

我有几个关于查看标准的问题

1. 删除一些应用的视图条件后，我是否需要执行查询 在应用相同或新的查看标准之前？
2. 此外，在应用每个视图条件后，是否需要执行查询？
3. 如果我想应用的第一个查看条件是使用 testVO.applyViewCriteria(vc); 应用的，我之前是否需要删除不需要的查看条件，还是会applyViewCriteria(vc) 删除所有现有的查看条件？

我在下面的代码中试图做的是删除任何应用的视图标准，然后应用我想要应用的新视图标准。

    testVO.getViewCriteriaManager().removeApplyViewCriteriaName("findByvc1");
    testVO.getViewCriteriaManager().removeApplyViewCriteriaName("findByvc2");
    testVO.getViewCriteriaManager().removeApplyViewCriteriaName("findByvc3");
    //testVO.executeQuery();
    
    ViewCriteria vc = testVO.getViewCriteriaManager().getViewCriteria("findByvc1");
    VariableValueManager vm = testVO.ensureVariableManager();
    vm.setvariableValue("vc1Var",123);
    testVO.applyViewCriteria(vc);
    //testVO.executeQuery();
    ViewCriteria vc1 = testVO.getViewCriteriaManager().getViewCriteria("findByvc3");
    vm.setvariableValue("vc3Var","test");
    testVO.applyViewCriteria(vc1,true);
    testVO.executeQuery();

解决方法

这是我讨论如何在 Oracle ADF 中以编程方式应用视图条件的文章：https://cedricleruth.com/how-to-apply-a-viewcriteria-programmatically-in-adf/ 代码提取：

/**
 * Apply view criteria named MyViewCriteria to it's ViewObject
 * by getting it through the binding iterator MyViewObjectIterator
 */
public void applyViewCriteriaOnViewObjectByIteratorName(String MyViewCriteriaName,String MyViewObjectIteratorName) {
    try {
        //Get The viewObject from the iterator define in the current binding context
        ViewObject vo = this.getViewObjectFromIteratorName(MyViewObjectIteratorName)
        //Get all it's ViewCriteria using the ViewCriteriaManager of the ViewObject
        ViewCriteriaManager vcm = vo.getViewCriteriaManager();
        //Get the specified View Criteria
        ViewCriteria vc = vcm.getViewCriteria(MyViewCriteriaName);
        //Apply the ViewCriteria to the ViewObject
        vo.applyViewCriteria(vc);
        //Note: If you need to apply this view criteria on top of already applied view criteria
        //without removing them you can add the following boolean parameter : 
        //vo.applyViewCriteria(vc,true);
        
        //That's all you need if the iterator is set to be refresh after this
        //If not you can force the ViewObject to execute by uncommenting the following :
        //vo.executeQuery(); 
    } catch (NullPointerException e) {
        //Log and warn for null
        //Often occur when there is an error in the provided attributes 
        //(MyViewCriteriaName,MyViewObjectIteratorName)
    } catch (Exception e) {
        //Log and warn for other exceptions - Should never be needed
}
    
/**
 * Useful function to get ViewObject from IteratorName
 * The iterator need to have a least one binding define in the current page
 * In this gist it's a private but i advice setting it as a public static in an utility class available for the whole Controller
 */
 private ViewObject getViewObjectFromIteratorName(String MyViewObjectIteratorName) {
    ViewObject vo = null;
    try {
        DCBindingContainer bindings = (DCBindingContainer) BindingContext.getCurrent().getCurrentBindingsEntry();
        DCIteratorBinding iterator = bindings.findIteratorBinding(MyViewObjectIteratorName);
        vo = iterator.getViewObject();      
    } catch (NullPointerException e) {
        //Log and warn for null
        //Often occur when there is an error in the provided attributes 
        //or if the iterator doesn't have a least one binding define in the current page
    }
    return vo;
 }

回答您的问题：

1. 如果您的 vo 已设置为刷新，则不需要 executeQuery()。例如，如果您在迭代器上有一个 ppr。如果不是，您需要执行查询来强制刷新您的迭代器。
2. 您不需要在每个 applyViewCriteria 之后执行查询，尤其是当您使用辅助布尔参数为 true 时，它​​“在已应用的视图标准之上应用此视图标准”。它们都将作为层相互应用，并在您最后执行查询时进行设置。
3. 如果您没有将次要布尔参数添加为 true，您的视图标准将是唯一应用的标准，所有其他标准都将被自动删除。