ADF Baiscs: Define and remove named bind variable in viewObject at runtime programmatically

This post is about creating named bind variable in viewObject at run time and filter viewObject using this bind variable in WHERE Clause of ViewObject programmatically .

Defining WHERE Clause and Bind Variable name and default value -

        //Get ViewObject
        ViewObject vo = iter.getDepartments();

        //Apply desired WHERE Clause and declare bind variable name
        vo.setWhereClause("DEPARTMENT_NAME=:BindDepartmentName");

        //Define this variable as ViewObject Bind Variable , You can also set default value for this
        vo.defineNamedWhereClauseParam("BindDepartmentName", "Purchase", null);

        // Execute ViewObject to finally apply where clause
        vo.executeQuery();

Setting value of Bind Variable-

        //Setting Value of Bind Variable
        vo.setNamedWhereClauseParam("BindDepartmentName", "Finance");
        vo.executeQuery();

Getting value of Bind Variable-

        //Get value of Bind Variable
        vo.getNamedWhereClauseParam("BindDepartmentName");

Removing WHERE Clause and Bind Variable after use-

        //Remove where clause
        vo.setWhereClause(null);
        //Remove Bind Variable
        vo.removeNamedWhereClauseParam("BindDepartmentName");
        vo.executeQuery();

Cheers :) Happy Learning

Overriding default query listener ,field validation of af:query- Oracle ADF

Hello All,

this post talks about a common requirement - can we apply custom validation in af:query fields ? yes , we can do that by overriding default query listener of af:query component

What af:query is ?

see- Oracle Docs-af:query

"The query component provides the user the ability to perform a query based on a saved search or personalize saved searches. The component displays a search panel with various elements, each of which help the user to accomplish various tasks."

Follow steps to apply validation on af:query-

• Here i am taking example of Departments table of HR Schema
• First create business components for Departments table

• then create  bind variables and a view-criteria in departments view object
  
  
  
  
  
• See the view criteria is applied for LocationId, ManagerId and Department Name

• Now create a page and drop criteria with table on page- it will look like this

• Next is to select af:query on page and go to property inspector and copy text of default query listener

• Now create a managed bean and create a custom query listener for af:query
  
  
  
   
• In this custom query listener , in this example i am checking for negative Location Id and Manager Id, if there is any negative values ,custom method will show a message otherwise default queryListener will be executed
• We can get af:query's components value using 2 methods
  First One  - Using Bind Variable (getNamedWhereClauseParam)
  Second One - Using QueryDescriptor and ConjunctionCriterion
• I'm going to explain both methods - see code of custom query listener using first method, two generic methods will be used in this process to invoke expression language and to get BindingContainer of current context



    /**Method to invoke EL Expression
     * @param el
     * @param paramTypes
     * @param params
     * @return
     */
    public static Object invokeEL(String el, Class[] paramTypes, Object[] params) {
        FacesContext facesContext = FacesContext.getCurrentInstance();
        ELContext elContext = facesContext.getELContext();
        ExpressionFactory expressionFactory = facesContext.getApplication().getExpressionFactory();
        MethodExpression exp = expressionFactory.createMethodExpression(elContext, el, Object.class, paramTypes);

        return exp.invoke(elContext, params);
    }

    /**Method to get Binding Container of current page
     * @return
     */
    public BindingContainer getBindings() {
        return BindingContext.getCurrent().getCurrentBindingsEntry();
    }



• See the first method to get af:query components value and validate that



    /**Custome Query Listener- Using getNamedWhereClauseParam
     * @param queryEvent
     */
    public void customQueryListener(QueryEvent queryEvent) {
        String deptName = null;
        Integer locId = null;
        Integer mgrId = null;

        /**Get Iterator of Table*/
        DCIteratorBinding iter = (DCIteratorBinding)getBindings().get("DepartmentsView1Iterator");

        /**Get ViewObject from Iterator*/
        ViewObjectImpl vo = (ViewObjectImpl)iter.getViewObject();

        /**Get Bind Variable's Value*/
        if (vo.getNamedWhereClauseParam("LocIdBind") != null) {
            locId = Integer.parseInt(vo.getNamedWhereClauseParam("LocIdBind").toString());
        }
        if (vo.getNamedWhereClauseParam("MgrIdBind") != null) {
            mgrId = Integer.parseInt(vo.getNamedWhereClauseParam("MgrIdBind").toString());
        }
        if (vo.getNamedWhereClauseParam("DeptNmBind") != null) {
            deptName = vo.getNamedWhereClauseParam("DeptNmBind").toString();
        }

        /**Check for Negative values*/
        if ((locId != null && locId < 0) || (mgrId != null && mgrId < 0)) {
            FacesMessage msg = new FacesMessage("Id Value can not be negative");
            msg.setSeverity(FacesMessage.SEVERITY_ERROR);
            FacesContext.getCurrentInstance().addMessage(null, msg);
        } else {
            /**Execute default query listener with help of invokeEL method*/

            invokeEL("#{bindings.DepartmentsViewCriteriaQuery.processQuery}", new Class[] { QueryEvent.class },
                     new Object[] { queryEvent });
        }
    }



• And Second Method using QueryDescriptor is-



    /**Custom Query Listener-Using QueryDescriptor
     * @param queryEvent
     */
    public void customqueryProcess(QueryEvent queryEvent) {
        String deptName = null;
        Integer locId = null;
        Integer mgrId = null;

        /**Reference-Frank Nimphius Example- ADF Code Corner
       * http://www.oracle.com/technetwork/developer-tools/adf/learnmore/85-querycomponent-fieldvalidation-427197.pdf
       * */
        QueryDescriptor qd = queryEvent.getDescriptor();

        ConjunctionCriterion conCrit = qd.getConjunctionCriterion();
        //access the list of search fields
        List<Criterion> criterionList = conCrit.getCriterionList();
        //iterate over the attributes to find FromDate and ToDate
        for (Criterion criterion : criterionList) {
            AttributeDescriptor attrDescriptor = ((AttributeCriterion)criterion).getAttribute();

            if (attrDescriptor.getName().equalsIgnoreCase("DepartmentName")) {
                deptName = (String)((AttributeCriterion)criterion).getValues().get(0);

            } else {
                if (attrDescriptor.getName().equalsIgnoreCase("LocationId")) {
                    locId = (Integer)((AttributeCriterion)criterion).getValues().get(0);

                }
            }
            if (attrDescriptor.getName().equalsIgnoreCase("ManagerId")) {
                mgrId = (Integer)((AttributeCriterion)criterion).getValues().get(0);

            }
        }
        if ((locId != null && locId < 0) || (mgrId != null && mgrId < 0)) {
            FacesMessage msg = new FacesMessage("Id Value can not be negative");
            msg.setSeverity(FacesMessage.SEVERITY_ERROR);
            FacesContext.getCurrentInstance().addMessage(null, msg);
        } else {
            /**Process default query listener*/
            invokeEL("#{bindings.DepartmentsViewCriteriaQuery.processQuery}", new Class[] { QueryEvent.class },
                     new Object[] { queryEvent });
        }

    }



• Now Run your application and check it for negative values

Cheers- Download Sample App Happy Learning :-)