JDeveloper 12.2.1.4: af:chooseDate

The new JDeveloper 12.2.1.4 has added an enhancement an a new feature to the af:chooseDate component. We are looking at both in this article.

Enhancement

The enhancement is that you can now set a default date which is shown as the selected date when the field you show the af:chooseDate for is empty. In the older JDeveloper versions, the selected date was always the current date. The image below shows the situation of how the af:chooseDate component looks like:

The af:inputText ‘Datum’ is not set and because of this, the af:chooseDate shows the current date (when I took the picture) as the selected date. Problem is, that there are use cases where you don’T want the current date to be the selected date, e.g. your use case might want to show the next Friday after the current date as the selected date. This was not easily possible.

Now, the enhancement to the af:hcooseDate component allows us to set a default date via the property ‘defaultValue’. When set to a literal value, this will be parsed as “yyyy-MM-dd hh:mm:ss” or “yyyy-MM-dd”.

I added an af:inputdate ‘Set DefaultDate’ to allow selection of a date which then will be used as the default date in the af:chooseDate for the ‘Datum’ field. The current date is marked with gray and the date set in the ‘Set Default Date’ is shown as the selected date.

As you see, the ‘Datum’ field is still empty. If you select a date like ‘12/20/2019’ you get

Sample Code

<af:inputDate label="Set Default Date:"
     Nhn ng  value="#{bindings.defaultDate1.inputValue}" id="id2"
     autoSubmit="true"/>
<af:spacer id="s1" height="10px"/>
<af:panelGroupLayout id="pgl2" layout="horizontal">
<af:inputDate label="Datum" id="id1" chooseId="cd1"/>
<af:chooseDate id="cd1"
    defaultValue="#{bindings.defaultDate1.inputValue}"
    partialTriggers="id2"/>

New Feature: “Multiple Date Selection”

The af:chooseDate component has another feature added. Now you can select multiple dates at once. This feature is very handy as you can now use one af:chooseDate to get a start date and an end date or date ranges. The image below shows the component with multiple dates selected.

The interesting thing is, that there is no implementation for this hardcoded in the component. Meaning is that we, the developers, need to implement this feature ourselves. For this ADF provides two new client events ‘load’ and ‘dateSelection’ that are triggered by the af:chooseDate component. We use these client events to implement the multi-select feature. The load event can be used to pass an array of dates to the component which are then shown as selected. This event is triggered when the component loads, as the name implies. The dateSelection event is triggered each time a user selects a date. It passes information about the keyboard state so that we can handle range selection.

To make it easier, the ADF Rich Client Demo has a sample implementation of the needed JavaScript code which I used as the base of my implementation:

/**
 * Shows a popup from an "action" type event.
 * @param {AdfActionEvent} actionEvent the event being handled
 */
var dates = [];
var minDate;
var maxDate;

function dateSelectionEventHandler(event) {
    var eventSource = event.getSource();
    var selectedDate = event.getSelectedDate();
    var modifier = event.getModifiers();

    if (modifier.indexOf(AdfRichChooseDate.MULTI_SELECTION) !=  - 1) {
        dates.push(selectedDate);
    }
    else if (modifier.indexOf(AdfRichChooseDate.RANGE_SELECTION) !=  - 1) {
        if (!minDate || (minDate.getTime() > selectedDate.getTime())) {
            minDate = selectedDate;
        }
        if (!maxDate || (maxDate.getTime() < selectedDate.getTime())) {
            maxDate = selectedDate;
        }
        var timeDiff = Math.abs(maxDate.getTime() - minDate.getTime());
        var diffDays = Math.ceil(timeDiff / (1000 * 3600 * 24)) + 1;
        dates = []
        for (var i = 0;i < diffDays;i++) {
            var selDate = new Date(minDate.getFullYear(), minDate.getMonth(), minDate.getDate() + i, 0, 0, 0, 0);
            if (!eventSource.isDisabled(selDate))
                dates.push(selDate)
        }
    }
    else if (modifier.indexOf(AdfRichChooseDate.SINGLE_SELECTION) !=  - 1) {
        minDate = null;
        maxDate = null;
        dates = []
        dates.push(selectedDate)
    }
    eventSource.setSelectedDates(dates);
}

function chooseDateLoadEventHandler(event) {
    var eventSource = event.getSource();
    eventSource.setSelectedDates(dates);
}

function processSelectedDates(event) {
    component = event.getSource();
    AdfCustomEvent.queue(component, "processSelectedDates", 
    {
        payload : dates
    },
    true);
    event.cancel();
}

There are three JavaScript funtions:

  1. dateSelectionEventHandler(event) handles the selection of one or more dates
  2. chooseDateLoadEventHandler(event) handles the inital load of hte component and allows us to set dates as selected
  3. processSelectedDates(event) is the funtion which passes the selected dates to a server event

The functions are added to the af:chooseDate compponent as client listerner

<af:chooseDate id="cd2" clientComponent="true">
    <af:clientListener type="dateSelection" 
        method="dateSelectionEventHandler"/>
    <af:clientListener type="load" method="chooseDateLoadEventHandler"/>
</af:chooseDate>

To pass the selected dates to a server event a button is used like

<af:button text="Selected Dates" id="b2">
    <af:clientListener method="processSelectedDates" type="action"/>
    <af:serverListener type="processSelectedDates"
        method="#{viewScope.ChooseDateBean.procressSelectedDates}"/>
 </af:button>

The image below shows the selected dates once the button ‘Selected Dates’ is clicked.

This JavaScript function simply passes the array of selected dates as payload from the client to the server. There the dates are just stored in a bean variable. This variable is used to show the dates in an af:outputText.

The same works for a range selection as shown below

And after the button ‘Selected Dates’ is clicked we get

The sample can be downloaded from GitHub BlogChooseDate or directly as a zip. The sample is written using JDeveloper 12.2.1.4 and doesn’t use any DB connection.

JDeveloper 12.2.1.4: af:panelTabbed

The new JDeveloper 12.2.1.4 provides some new features and enhancements. In the next couple of posts we are going to investigate some of them.

We start with the af:panelTabbed component. There is an enhancement fro this component we all waited for a long time. Vertical stacked tabs with icons and text. This sounds like a small thing, but in earlier versions of ADF vertical stacked tabs could only show icons.

We are calling tabs vertical stacked, if the tab is on the left or right side of the panel. Horizontal stacked tabs are the ones at the top or the button of the panel.

Vertical Stacked Tab with Icons and Text

As said before, in earlier versions of ADF you needed to do a workaround to get tabs on the left or right showing an icon, text or both. You needed to create an icon from the icon, Text or icon with text and add it to the af:showDetailItem. The drawback was that you couldn’t just edit the text (e.g. correcting a spelling mistake) or had to generate different such icons for different languages along with some logic to exchange the icon according to the selected language.

The new af:panelTabbed has a new property ‘verticalTabMode‘ with two modes:

  • iconOnly this mode behaves like the old versions and only shows an icon defined for the af:showDetailItem
  • iconAndText this mode shows an icon and the text defined in the text property of the af:showDetailItem
af:panelTabbed with verticalTabMode=”iconOnly’
af:panelTabbed with verticalTabMode=”iconAndText’

The images above show the af:panelTabbed with the new verticalTabMode. The sample application for this can be downloaded from GitHub BlogPanelTabbed. It does not use a DB connection and was built using JDeveloper 12.2.1.4.

JDev 12c: Multi Line Button

An interesting question came up in the JDeveloper & ADF ODC space. A user asked how to display a button which shows a long text in multiple lines.

The image above shows an af:button with a longer text. If you don’t have enough space in your layout to show such a long text in a button, you can shorten the Text. If this is not a acceptable, one solution is to break the long text into multiple lines.

Think about an af:panelSplitter which should show the same button

but the space i for the left pane in the splitter s limited. The result will be that the text of the button can’t be read. In other layouts the button might overflow the given space. his can crumble your whole page layout.

In this blog I’ll show you how to design a button which can handle this situation by showing the text in multiple lines. The green dotted rectangles shows the size of the layout container. This is for information only.

As you see in the image above, the text of the button breaks into multiple lines if the space is not wide enough to show it in one line. If we move the splitter to the right you see the effect

Solution

The solution is to create a style class for the button which we use for button which should be able to show their text in multiple lines. This style class is put into a skin to make it available to the ADF application.

.multiLineButton af|button::text {
    white-space: normal; 
}

The usage of the style class is simple as we see in the sample code for the af:panelSplitter

<af:panelSplitter id="ps1" splitterPosition="100" orientation="horizontal" dimensionsFrom="parent">
	<f:facet name="first">
	        <af:button text="This Button has a very long text to show" id="b3"/>
        </f:facet>
        <f:facet name="second">
                <af:button text="This Button has a very long text to show" id="b4"
                           styleClass="multiLineButton"/>
        </f:facet>
</af:panelSplitter>

You can download the sample BlogMultilineButton (or the zipped workspace) from GihHub. The code was developed using JDeveloper 12.2.1.3 and doesn’t use a DB connection.

Update: InputNumberSpinbox without Spin inside af:query

A user asked how to get rid of the spin buttons if the InputNumberSpinbox is used in an af:query component?

Whenever you have a number attribute in a VO and use it in a view criteria which you then use to show an af:query using this view criteria, the af:query uses an af:inputNumberSpinBox in the query panel to allow the user to enter values. The problem is, that you can’t control how the components rendered inside an af:query is rendered. There are no properties you can change which are available if you use the same component directly.

af:query with af:inputNumberSpinBox and spin buttons

Using the af:inputNumberSpinBox in the af:query has the same advantage as I mentioned in the original post.

And the same disadvantage too. In most cases, you don’t want or need the up/down buttons to select a number. Well, this can be done by adding the same style class we added to the af:numberInputSpinBox to the af:query component. The result can be seen in the below image

And we get the same behavior inside the af:query component too.

The reason this works is, that the af:query uses an af:inputNumberSpinBox in the query panel. The skin selector we used in the skin file works for the af:numberInputSpinBox too.

As you see, if you select the af:query in the skin file and hover over the spin button, it tells you which selector is used. This is the same selector we use in our skin file

I added another sample which I extended from the original one build with JDeveloper 12.2.1.1.0. This sample uses the HR DB schema and can be downloaded from GitHub BlogInputSpinBoxWithoutSpinV2

Jdev 12c: Implementing SQL IN Clause in an ADF ViewObject Query or ViewCriteria (Part 2)

In part one, showed how to implement a SQL IN clause in ADF. Now I show how to use this technique in a ViewCriteria or directly in a query of a view object.

We have to solve a couple of problems before we can really use the technique from part one in a ViewCriteria. As you know, when using a ViewCriteria, you select an operator which in turn is translated into SQL code. So, we have to find a way to create a new operator which will then be used to create the needed SQL code.

The technique to do this comes from an older post. Please look at Extending ViewCriteria to use SQL CONTAINS where I showed the basics on how to do this. The older post was designed for JDeveloper 11.1.2.1.0. Using the current JDeveloper version 12.2.1.3 give some ways for improvement of the earlier code.

The first improvement is that JDeveloper 12.2.1.3 allows us to introduce custom operators to view criteria. In the older sample, I had to use the description field of the ViewCriteria to pass information which SQL to generate. Now we can define an operator named ‘IN’ and use it in the ViewCriteria like any other default operator.

The next problem is how to generate the SQL shown in part one when the new custom operator ‘IN’ should be used. One of the big advantages of ADF is reusability. We use a base class which extends from ViewObjectImpl and use this new base class in the project.

The base class is named BaseViewObjectForSqlInClause were we implement the needed method

public String getCriteriaItemClause(ViewCriteriaItem aVCI)

which gets called for each part or item of a ViewCriteria. See the code of hte base class below.

Base Class

public class BaseViewObjectForSqlInClause extends ViewObjectImpl {
    private static ADFLogger _logger = ADFLogger.createADFLogger(BaseViewObjectForSqlInClause.class);

    // comma-separated list of custom operators. Each custom operator muast have a ',' at the end as delimeter!
    private static final String CUSTOM_OPERATORS = "IN,";

    public BaseViewObjectForSqlInClause(String string, ViewDefImpl viewDefImpl) {
        super(string, viewDefImpl);
    }

    public BaseViewObjectForSqlInClause() {
        super();
    }

    /**
     * Check if a given criteria item tries to use an 'IN' operator using a bind parameter (comma seperated list of strings).
     * Create special SQL clause for 'IN' operator
     * @param aVCI Criteria item
     * @return where clause part for the criteria item
     */
    @Override
    public String getCriteriaItemClause(ViewCriteriaItem aVCI) {
        // we only handle the SQL 'IN' operator
        String sqloperator = aVCI.getOperator();
        // add comma to operator as delimiter
        boolean customOp = CUSTOM_OPERATORS.indexOf(sqloperator.concat(",")) >= 0;
        customOp |= sqloperator.indexOf("NVL") >= 0;
        if (customOp) {
            ArrayList<ViewCriteriaItemValue> lArrayList = aVCI.getValues();
            if (lArrayList != null && !lArrayList.isEmpty()) {
                // check if the criteria item has bind parameters (only the first if of interest here as the IN clause onlyallows one parameter)
                ViewCriteriaItemValue itemValue = (ViewCriteriaItemValue) lArrayList.get(0);
                if (itemValue.getIsBindVar()) {
                    // get variable and check if null values should be ignored for bind parameters
                    Variable lBindVariable = itemValue.getBindVariable();
                    Object obj = ensureVariableManager().getVariableValue(lBindVariable.getName());
                    boolean b = aVCI.isGenerateIsNullClauseForBindVariables();
                    if (b && obj == null) {
                        // if null values for bind variables should be ignored, use the default getCriteriaItemClause
                        return super.getCriteriaItemClause(aVCI);
                    }

                    try {
                        // we only handle strings data types for bind variables
                        String val = (String) obj;
                    } catch (Exception e) {
                        // the bind variabel has the wrong type! Only Strings are allowed
                        _logger.warning("Bind variabel for SQL " + sqloperator +
                                        " clause is not of type String! -> No custom SQL clause created! (Class: " +
                                        obj.getClass() + ", Content: " + obj + ", Variable: " +
                                        lBindVariable.getName() + ", View: " + this.getName() + ")");
                        String s = ":" + lBindVariable.getName() + " = :" + lBindVariable.getName();
                        return s;
                    }

                    // only handle queries send to the db
                    if (aVCI.getViewCriteria()
                            .getRootViewCriteria()
                            .isCriteriaForQuery()) {
                        String sql_clause = null;
                        switch (sqloperator) {
                        case "IN":
                            sql_clause = createINClause(aVCI, lBindVariable);
                            break;
                        default:
                            _logger.severe("Unknown custom operator '" + sqloperator + "' found! -> do nothing!");
                            break;
                        }

                        return sql_clause;
                    } else {
                        // bind variable not set or
                        // for in memory we don't need to anything so just return '1=1'
                        return "1=1";
                    }
                }
            }
        }

        return super.getCriteriaItemClause(aVCI);
    }

    private String createINClause(ViewCriteriaItem aVCI, Variable lBindVariable) {
        // start build the sql 'IN' where clause (COLUMN is the name of the column, bindParam the name of the bind variable):
        // COLUMN IN (SELECT regexp_substr(:bindParam,'[^,]+',1,level) FROM dual CONNECT BY regexp_substr(:bindParam,'[^,]+',1,level) IS NOT NULL
        // get flagg to create an sql where clause which ignores the case of the bind parameter
        boolean upper = aVCI.isUpperColumns();
        String sql_in_clause = null;
        StringBuilder sql = new StringBuilder();
        if (upper) {
            sql.append("UPPER(");
        }
        sql.append(aVCI.getColumnNameForQuery());
        if (upper) {
            sql.append(")");
        }
        sql.append(" ").append(aVCI.getOperator());
        sql.append(" (select regexp_substr(");
        if (upper) {
            sql.append("UPPER(");
        }
        sql.append(":");
        sql.append(lBindVariable.getName());
        if (upper) {
            sql.append(")");
        }
        sql.append(",'[^,]+', 1, level) from dual connect by regexp_substr(");
        if (upper) {
            sql.append("UPPER(");
        }
        sql.append(":").append(lBindVariable.getName());
        if (upper) {
            sql.append(")");
        }
        sql.append(", '[^,]+', 1, level) is not null)");
        sql_in_clause = sql.toString();

        _logger.finest("generated SQL-IN clause: " + sql_in_clause);

        return sql_in_clause;
    }
}

Using Base Class in Project

To use the base class in all new created ViewObjects of the project, we change the models project properties

Now, whenever you create a new ViewObject, the new base class is used and the SQL IN operator can be used in the VOs view criteria.

You can change any existing ViewObject to use the BaseViewObjectForSqlInClause by changing the extends clause in the class definition by hand.

Creating a ViewCriteria Using the Custom IN Operator

All pieces are in place and using the IN operator is pretty easy. We start by creating a new ViewObject named EmployeesOfDepartmentsViewCriteria

Now we have a ViewObject based on an EntityObject for the Employees. We need to make one change. The DepartmentId is an Integer type attribute, the comma-separated list is of type String (containing numbers). This doesn’t match. We add another attribute to the ViewObject of type String which we calculate from the DepartmentId Integer attribute. We change the SQL query for this by selecting the ‘Query’ node first unselecting the checkbox ‘Calculate Department Query at Runtime (recommended)’, second select the checkbox ‘Write Custom SQL’ and third add the line ‘to_char(Employees.DEPARTMENT_ID) DEPARTMENT_ID_STR,’ to the query.

Once this new ViewObject has been created, we add a ViewCriteria to it

If you like, you can turn off the checkbox ‘Ignore Case’ as it is not needed. The numbers are always lower case.

Running the ApplicationModule in the Tester

At this stage, we can test run the application module in the Application Module Tester (see JDeveloper & ADF: Use the Application Module Tester (BC4J Tester) to Test all your BusinessLogic).

Click the binocular button to select the ViewCriteria we created and click ‘Find’

Which will open a dialog asking for the value of the bind variable

Clicking ‘OK’ will show the result as

Running the ViewCriteria on a Page

Finally, we can add the ViewCriteria to a page as af:query and test it there. I’ll spare the exact howto here and just show hte running application.

Or with different parameters and spaces

You can download the sample application from GitHub BlogSqlInClause.

The Sample was built using JDeveloper 12.2.1.3 (but it should work in all 12c versions) and uses the HR DB schema.

JDev 12.2.1.3: Multi select component table filter

In this blog article, I show how to use a multi-select component as a filter in a table. The sample is based on an older sample from Frank Nimphius (98. How-to use multi select components in table filters). The sample was built for JDev 11g R1 and R2.

It works using 12c too, but you get deprecation warnings after the migration. A user on the JDeveloper & ADF forum asked if I could provide a sample running in 12c without the deprecation warnings.

I will only show how to rewrite the bean method which is called when the user enters one or more values in the filter. The remaining part of the original sample works without a change in 12c.

To better understand what I’m talking about I show some images from the original blog:

The image above shows the sample table. Below we see the multi-select component to filter for multiple departments:

Please read the original blog entry to understand how to build the UI. The remaining part of this blog covers how to build the custom query listener method.

Custom Query Listener

In the original sample the two methods

...
Map _criteriaMap = fqd.getFilterCriteria();
...
fqd.setFilterCriteria(_criteriaMap);

are used which produce deprecation warnings in 12c

Starting from JDev 12.1.3 you can’t use the criteriaMap from the FilterableQueryDescriptor. Instead, you have to first get the ConjunctionCriterion from the FilterableQueryDescriptor and get the map of Criterion from it. The map holds the filter criteria entered by the user.

As you don’t use the criteria directly, you can’t set it back after generating the filter fro the multi-select. You work with the Criterion instead.

The new Method looks like

    /**
     * Custom Query Listener.
     * Applies af:selectMany choice values to the table filter criterion
     * @param queryEvent
     */
    public void onEmployeeTableQuery(QueryEvent queryEvent) {
        //user selected values
        ArrayList<Object> departmentIdArray = null;
        FilterableQueryDescriptor fqd = (FilterableQueryDescriptor) queryEvent.getDescriptor();

        //current criteria
        ConjunctionCriterion conjunctionCriterion = fqd.getFilterConjunctionCriterion();
        Map<String, Criterion> criterionMap = conjunctionCriterion.getCriterionMap();
        Criterion criterion = criterionMap.get("DepartmentId");

        //Translate DepartmentId array list to OR separate list of values
        StringBuffer deptIdFilterString = new StringBuffer();
        AttributeCriterion adfcriterion = null;
        // flag we set only if the DepartmentId filter is set (to reset the selection later)
        boolean flagDepIdFilter = false;
        if (criterion != null) {
            adfcriterion = (AttributeCriterion) criterion;
            Object object = adfcriterion.getValue();
            if (object != null) {
                flagDepIdFilter = true;
                departmentIdArray = (ArrayList<Object>) object;

                for (int argIndex = 0; argIndex < departmentIdArray.size(); argIndex++) {

                    //You need to know what is the underlying data type you are dealing
                    //with for the attribute. If you are on 11gR1 (11.1.1.x) then this
                    //type is jbo.domain.Number for numeric attributes.
                    //
                    //If you are on 11g R2 (11.1.2.x) this could be oracle.jbo.domain.Number,
                    //Integer or BigDecimal. If you use 11g R2, check the View Object for the
                    //attribute data type

                    if (argIndex == 0) {
                        //first argument has no OR

                        //this sample used oracle.jbo.domain.Number for the
                        //DepartmentId attribute
                        Number departmentId = (Number) departmentIdArray.get(argIndex);
                        deptIdFilterString.append(departmentId.toString());
                    } else {
                        //any subsequent argument is OR'ed together
                        deptIdFilterString.append(" OR ");
                        Number departmentId = (Number) departmentIdArray.get(argIndex);
                        deptIdFilterString.append(departmentId.toString());
                    }
                }
                //for some reasons, if in a single value select case, the
                //filter breaks and an error message is printed that the
                //String representation of the single value isn't found in
                //the list. The line below fixes the problem for filter values
                //that are positive numbers
                deptIdFilterString.append(" OR -1");
                String departmentIds = deptIdFilterString.toString();
                adfcriterion.setValue(departmentIds);
                fqd.setCurrentCriterion(adfcriterion);
            }
        }


        // preserve default query listener behavior
        //#{bindings.allEmployeesQuery.processQuery}

        FacesContext fctx = FacesContext.getCurrentInstance();
        Application application = fctx.getApplication();
        ExpressionFactory expressionFactory = application.getExpressionFactory();
        ELContext elctx = fctx.getELContext();

        MethodExpression methodExpression =
            expressionFactory.createMethodExpression(elctx, "#{bindings.allEmployeesQuery.processQuery}", Object.class,
                                                     new Class[] { QueryEvent.class });
        methodExpression.invoke(elctx, new Object[] { queryEvent });

        //restore filter selection done by the user. Note that this
        //needs to be saved as an ArrayList
        if (flagDepIdFilter) {
            adfcriterion.setValue(departmentIdArray);
            fqd.setCurrentCriterion(adfcriterion);
        }
    }

From the FilterableQueryDescriptor we get the ConjunctionCriterion and from this the map of Criterion. This map holds all filter values entered by the user in the filter of the table. We retrieve the one for the ‘DepartmentId’ and check if the value for it is not null. In this case, the criterion holds an array of the selected DepartmentId. From this array, we build a new string where we use the ‘OR’ operator to concatenate the array values.

Once this string is built, we set it back to the Criterion and execute the original query listener

You can download the sample from GtHubBlogMultiSelectComponentFilterTable for inspection and/or testing. The sample was built using JDev 12.2.1.3 and uses the HR DB schema.

JDeveloper: executeWithParams Problem: bind variable setters are not called

In one of my current bigger ADF projects (yes, there are still big ADF projects!) I had a problem with the ‘executeWithParams’ operation binding called from a bean. To understand the problem I first give a brief description.

Problem

We have a special string column in some of our VOs. For this column, there is a bind parameter which is added to the where clause of the VO. Getter and setter for this bind parameters are generated to be able to set this parameter safely. In the setter method, some checks are done and special formatting is applied to the passed value.

Now we used the VOs executeWithParams operation to create a search form. Hitting the button to execute the query gave us a wrong result. As it turned out, that the execWithParams operation passes the parameters to the VO but it doesn’t use the getter/setter methods for the parameter. The parameters are directly set into the slots by the VariableManager.

Solutions

We want to transform or convert the given parameter right in the query. This way the developer doesn’t need to think about or to remember that there should be a transformation of the parameter. A central solution is preferred. Two solutions come to mind.

Expose a method in the VO

One solution would be to create a method in the VO and expose this method in the client interface of the VO. Then this method is visible in the binding layer and you can use call the method instead of using executeWithParams.

This works OK, but if a developer uses the executeWithParams method, you’ll still don’t get the right result.

Change the behavior of the executeWithParams method

I looked for a direct hook into the executeWithParams method but did not find one 😦

However, it turned out that the executeWithParam method calls the executeQuery method of the VO. At this point, the parameters are all set. This is done in the background via the VariableManager used in VOs to keep track of the bind parameters and their different type. There are where clause parameters and parameters used in view criteria. The latter are handled differently but this is not essential for this solution. All we need to know is that the parameters are correctly set when the executeQuery method is called.

The solution is to overwrite the executeQuery method of the view object (or use a base class) and check the parameters before executing the query.

Implementing the solution

In an earlier blog “Dump VO query and it’s parameter with their values” I showed how to get to the parameters defined for a VO and dump their values. Instead of writing the values to the log file, we look for the parameter, change the value, if one is given and then execute the query with the now converted parameter.

I use reflection to check if a setter method for a parameter is defined in the VO. If this is the case, I call the setter with the value set by the user. This way the setter is called when the query is called via the executeWithParams method. The code to change the parameter has only to be written once in the setter.

Below is the code:

    @Override
    public void executeQuery() {
        _logger.info("executeQuery");
        transformHistoryParameter();
        dumpQueryAndParameters();
        super.executeQuery();
    }

    private void transformHistoryParameter() {
        VariableValueManager vm = ensureVariableManager();
        Variable[] variables = vm.getVariables();
        // check each parameter for this query
        for (Variable var : variables) {
            String varName = var.getName();
            try {
                String mName = "set" + varName;
                Class mvarType = var.getJavaType();
                Method m = this.getClass().getMethod(mName, new Class[] { mvarType });
                // check if method is a setter method
                if (isSetter(m)) {
                    Object val = vm.getVariableValue(var);
                    m.invoke(this, val);
                }
            } catch (NoSuchMethodException e) {
                // nothing to do if there is no setter defined
                return;
            } catch (IllegalAccessException | InvocationTargetException e) {
                // nothing to do if there is no setter defined
                return;
            }
        }
    }

    public boolean isGetter(Method method) {
        if (!method.getName().startsWith("get")) {
            return false;
        }
        if (method.getParameterTypes().length != 0) {
            return false;
        }
        if (void.class.equals(method.getReturnType())) {
            return false;
        }
        return true;
    }

    public boolean isSetter(Method method) {
        if (!method.getName().startsWith("set")) {
            return false;
        }
        if (method.getParameterTypes().length != 1) {
            return false;
        }
        return true;
    }

    public void dumpQueryAndParameters() {
        // get the query in it's current state
        String lQuery = getQuery();
        // Dump query
        _logger.info("---query--- " + lQuery);
        //get Valriables
        AttributeList attributeList = getNamedWhereClauseParams();
        String[] attributeNames = attributeList.getAttributeNames();
        if (attributeNames == null || attributeNames.length == 0) {
            _logger.info("--- No variables found");
        } else {
            _logger.info("---Variables:");
            for (int ii = 0; ii < attributeNames.length; ii++) {
                Object lObject = attributeList.getAttribute(ii);
                _logger.info("  --- Name: " + attributeNames[ii] + " Value: " +
                             (lObject != null ? lObject.toString() : "null"));
            }
        }
    }

Sample

The sample to see the code at work can be downloaded from GitHub BlogExecuteWithParamsProblem

It was implemented using JDeveloper 12.2.1.3 and the HR DB schema.

To make it easy, I used the HR DB schema and built a query on the EMPLOYEES table:

A forth bind variable is introduced in a view criteria

The transformation uses the pMail bind parameter and makes it uppercase.

    /**
     * Returns the bind variable value for pMail.
     * @return bind variable value for pMail
     */
    public String getpMail() {
        String val = (String) getNamedWhereClauseParam("pMail");
        _logger.info("value: " + val);
        return val;
    }

    /**
     * Sets <code>value</code> for bind variable pMail.
     * @param value value to bind as pMail
     */
    public void setpMail(String value) {
        _logger.info("value:" + value);
        String newVal = value;
        if (value != null) {
            newVal = value.toUpperCase();
            _logger.info("Value transformed to " + newVal);
        }
        setNamedWhereClauseParam("pMail", newVal);
    }

I know that it would be easy to without this code by just setting the ‘ignore case’ flag when defining the query, but this is just a sample of a change of a parameter.

The data model in the application module looks like

As you see I added a second instance of the EmployeesView and attached the view criteria to this instance. Running the application module in the tester (see JDeveloper & ADF: Use the Application Module Tester (BC4J Tester) to Test all your BusinessLogic)

We get

And the following log

Feb 08, 2019 3:05:38 PM de.hahn.blog.execwithparams.model.EmployeesViewImpl executeQuery
INFO: executeQuery
Feb 08, 2019 3:05:38 PM de.hahn.blog.execwithparams.model.EmployeesViewImpl setpMail
INFO: value:ski
Feb 08, 2019 3:05:38 PM de.hahn.blog.execwithparams.model.EmployeesViewImpl setpMail
INFO: Value transformed to SKI

Feb 08, 2019 3:05:38 PM de.hahn.blog.execwithparams.model.EmployeesViewImpl setpName
INFO: value: null
Feb 08, 2019 3:05:38 PM de.hahn.blog.execwithparams.model.EmployeesViewImpl setpDate
INFO: value: null
Feb 08, 2019 3:05:38 PM de.hahn.blog.execwithparams.model.EmployeesViewImpl dumpQueryAndParameters
INFO: —query— SELECT Employees.EMPLOYEE_ID, Employees.FIRST_NAME, Employees.LAST_NAME, Employees.EMAIL, Employees.PHONE_NUMBER, Employees.HIRE_DATE, Employees.JOB_ID, Employees.SALARY, Employees.COMMISSION_PCT, Employees.MANAGER_ID, Employees.DEPARTMENT_ID FROM EMPLOYEES Employees WHERE ( ( ( ( Employees.LAST_NAME LIKE ( :pName || ‘%’) ) OR ( :pName IS NULL ) ) AND ( ( Employees.EMAIL LIKE ( :pMail || ‘%’) ) OR ( :pMail IS NULL ) ) AND ( ( Employees.HIRE_DATE >= :pDate ) OR ( :pDate IS NULL ) ) ) )
Feb 08, 2019 3:05:38 PM de.hahn.blog.execwithparams.model.EmployeesViewImpl dumpQueryAndParameters
INFO: —Variables:
Feb 08, 2019 3:05:38 PM de.hahn.blog.execwithparams.model.EmployeesViewImpl dumpQueryAndParameters
INFO: — Name: pMail Value: SK
I
Feb 08, 2019 3:05:38 PM de.hahn.blog.execwithparams.model.EmployeesViewImpl dumpQueryAndParameters
INFO: — Name: pName Value: null
Feb 08, 2019 3:05:38 PM de.hahn.blog.execwithparams.model.EmployeesViewImpl dumpQueryAndParameters
INFO: — Name: pDate Value: null
Feb 08, 2019 3:05:38 PM de.hahn.blog.execwithparams.model.EmployeesViewImpl dumpQueryAndParameters
INFO: — Name: pSalary Value: null

We see, that executeQuery() is called, then setpMail is called and the value given in the UI is converted to uppercase. In the dump of the query, we see that the uppercase parameter is used for the query.

The same works with the other view object in the application module. Just try it out yourself. The sample has a small UI project allowing you to test it in the browser too.

JDeveloper: Creating a FULL OUTER JOIN View Object

On my todo list, I found a topic which I wanted to blog about for a long time. The problem is how to create a ViewObject, based on EntityObjects, which builds a full outer join between two tables.

For those of you who don’t know about full outer joins in SQL here is a short description from https://www.w3schools.com/sql/sql_join_full.asp:

The FULL OUTER JOIN keyword return all records when there is a match in either left (table1) or right (table2) table records.

Note: FULL OUTER JOIN can potentially return very large result-sets!

FULL OUTER JOIN Syntax:

SELECT column_name(s)
FROM table1
FULL OUTER JOIN table2 ON table1.column_name = table2.column_name;
Image to visualize a full outer join

There are not too many use cases where you need to use a full outer join, but they exist (e.g. https://searchoracle.techtarget.com/answer/Another-good-FULL-OUTER-JOIN-example or to compare two or more tables).

Problem: How can a full outer join be created in ADFbc?

I show how to create a VO based on Employees and Department EO using a full outer join on the department_id. This VO will return all departments with all their employees, departments which don’t have any employee and all employees who don’t have a department.

Following the syntax from above, we use an SQL statement like

SELECT Departments.DEPARTMENT_ID,
  Departments.DEPARTMENT_NAME,
  Employees.DEPARTMENT_ID AS DEPARTMENT_ID1,
  Employees.LAST_NAME,
  Employees.FIRST_NAME,
  Employees.EMPLOYEE_ID
  FROM DEPARTMENTS Departments
FULL OUTER JOIN EMPLOYEES Employees
ON Departments.department_id = Employees.department_id
ORDER BY Departments.department_id, Employees.last_name;

There are other SQL statements which produce the same result like

SELECT DISTINCT * FROM
  (SELECT d.department_id AS d_dept_id,
     d.DEPARTMENT_NAME,
     e.department_id AS e_dept_id,
     e.last_name last_name,
     e.FIRST_NAME
   FROM departments d
   LEFT OUTER JOIN employees e
   ON d.department_id = e.department_id
   UNION ALL
   SELECT d.department_id AS d_dept_id,
     d.DEPARTMENT_NAME,
     e.department_id AS e_dept_id,
     e.last_name,
     e.FIRST_NAME
   FROM departments d
   RIGHT OUTER JOIN employees e
   ON d.department_id = e.department_id
  )
ORDER BY d_dept_id, last_name;

The statement combines a left outer join with a right outer join. The ‘Select distinct….’ is used to eliminate duplicate rows which are returned for both joins. Anyway, the results are equal.

Solution

Now we can build the view object based on the two entity objects (Departments and Employees). We start by creating a new view object

and fill in the name as ‘DepEmpViewObj’. Make sure you select ‘Entity’ as ‘Data Source’

On the next wizard page shuttle the Departments and the Employees entities to the right

Now select the Departments entity and you get

Selecting the Employees entity you get

This we have to change as the join type is ‘inner join’ and not what we like to do. If you select the drop down menu you see

Hm, there is no ‘full outer join’ as joint type. We can’t create this type of join declaratively, we have to do this directly with a SQL statement. So, drop down the ‘Association’ field and select ‘none’

The final definition is

On the next page select the attributes

We don’t change anything in step 4 so we go to step 5. Here uncheck the ‘Calculate…’ checkbox and select the ‘Write Custom SQL’

Now we copy the SQL statement from above and copy it into the text area after deleting the current statement. Don’t forget to delete the ‘order by…’ part from the ‘Select:’ text area and add them into the ‘Order By:’ text field

We skip the steps 6,7 and 8 and add the view object to the application module in step 9

Finally, we finish the wizard and are ready to test the view object.

Running solution

Running the application module in the tester show the resulting table (only the last ~40 rows are shown)

We see departments without employees and we have one employee (see the last row) without an assigned department. All as expected.

To complete the application we add the new DepEmpViewObj onto a page as a table. Running it we get the same result as in the tester.

You can download the sample from GitHub BlogFullOuterJoin. The sample was built using JDeveloper 12.2.1.3 and uses the HR DB. The same technique can be used with other JDeveloper versions too.

JDeveloper 12.2.1.3: REST POST Sample

Lately, I got a request to build a REST POST sample using an ADF REST DataControl. Well, here we go.

First of all, we need a REST API which allows us to create data as this will be translated to REST POST call. I deliberately don’t want to use an ADF based REST service as there are samples available for this.

Looking for free REST API services which allow creating data I found “reqres’ (http://reqres.in), a free ‘hosted REST-API ready to respond to your AJAX requests’. This service can be used to test REST calls using any verb you like. It promises to be online 24/7.

Let’s start by creating a new ADF Web Application. If we would only test the REST service we could have created a custom application, but I want to show the viewController part too, so the ADF Web Application is just fine.

I don’t show how to do this here as you can see it done here ‘Why and how to write reproducible test cases’

As we don’t use the ADFModel project you can delete this empty project if you like. After creating the initial workspace, we create a new project from the gallery as a ‘Custom Project’

I named the new project ‘BRPWebService’, but you can name the project anything you like. Inside the new project we new create a ‘Web Service Data Control (SOAP/REST)’:

After selecting this, a wizard will ask which kind of ‘Web Service Data Control’ we like to create. We choose REST and now have to specify the base URL to the REST service API.

We skip the next page as there is no OWSM Policy needed to access the REST API

In step 3 we define the path we want to use after the base URL. From the web page of the service, we see a bunch of possible API endpoints.

For this test, we use the ‘api/users’ path. The whole URL now is ‘http://reqres.in/api/users’. To test the creation of data we use the POST verb, so we select the POST. To make sure the service is functional, we add the GET verb too.

After naming the methods getUsers for the GET and createUser for the POST, we need to give the wizard info about the parameters the API expects and the response we get when the call is successful. When we click on the GET verb on the web page, we get all the info we need.

All JSON code samples are available from the web page or from this blog in the appendix

We copy the response from the web page and pate it o the ‘Response Sample’ field and create a parameter ‘page’ in the parameter section of the next wizard step.

The same we do for the createUser method. Here we have to copy the request parameter JSON and the response JSON from the web page.

On the next page, we test the Web Service Data Control

This completes the creation process. We can now run the Datacontrol from inside JDeveloper by right-clicking the data control and choosing ‘Run’

Testing the getUsers method with the parameter set to 2 we receive the right answer

Now, let’s try the POST verb by trying out the createUser method. As a parameter, we pass some JSON and after executing the method we get a JSON part back telling us the new Id of the user.

Everything works. Please remember that we only use a ‘fake’ service which accepts our JSON, but will not add any data!

Sample Application

For the fun of it, I developed a ViewControler which uses the REST Data Control. It allows to ask for users by providing a page to load, or you can test the POST verb to create a ‘fake’ new user.

The final application can be downloaded from GitHub BlogRestPost. It was built using JDeveloper 12.2.1.3 without a DB connection.

After starting the app we see this UI

The service allows getting users in page mode, three users per page. So, enter 3 into the ‘Page’ filed and we get

Now, filling ‘name’ and ‘job’ field and clicking the createUser button we get

The service returns a new user with a new ID and the timestamp when the user was created.

Appendix

JSON reponse for GET api/users?page=2

{
    "page": 2,
    "per_page": 3,
    "total": 12,
    "total_pages": 4,
    "data": [
        {
            "id": 4,
            "first_name": "Eve",
            "last_name": "Holt",
            "avatar": "https://s3.amazonaws.com/uifaces/faces/twitter/marcoramires/128.jpg"
        },
        {
            "id": 5,
            "first_name": "Charles",
            "last_name": "Morris",
            "avatar": "https://s3.amazonaws.com/uifaces/faces/twitter/stephenmoon/128.jpg"
        },
        {
            "id": 6,
            "first_name": "Tracey",
            "last_name": "Ramos",
            "avatar": "https://s3.amazonaws.com/uifaces/faces/twitter/bigmancho/128.jpg"
        }
    ]
}

JSON payload and response for POST api/create

Payload
{
    "name": "morpheus",
    "job": "leader"
}

Reponse
{
    "name": "morpheus",
    "job": "leader",
    "id": "783",
    "createdAt": "2018-11-19T21:42:47.556Z"
}

JDeveloper: Task Flow with optional Parameters

In one of my current projects, I came across a wired problem concerning a task flow which uses parameters to configure the flow. To make it simple to understand the problem I made up a fictive use case.

Use Case

This is not a real use case, but an abbreviation of it just to show the problem and how to resolve it. It might not make sense in real life, but it allows to show the problem.

We like to see a form to enter some data. One of the fields the user can enter should be used to select a specific layout of the following pages. Ony Layout should be horizontal and one should be vertical.

The layout should allow showing a title with a number, a text part, and a footer part. Each of the parts is optional, only the layout must be specified.

The flow can be used at different points in different flows in the application.

Implementation

The implementation is easy. We build a task flow, build with pages, and add 5 parameters to it. This task flow looks like this:

In a router component, we check the required parameter to decide which layout to use. The ‘none’ page is used if the parameter is not ‘v’ or ‘h’.

For the layout pages, which implement the layout part, I used a af:panelGridLayout with the right number of rows and columns. Here is the vertical.jsf page

Or the source view

The other pages can be found in the sample which was built using JDeveloper 12.2.1.3. You can download the sample using the link at the end of the blog.

Now that we have the reusable task flow we need another task flow (adfc-config.xml in this case) to show how to use the use of the task flow.

We see an index page which calls the task flow using three different navigations (toPageNoParam, toPageAllParam and toPageTextOnly). The difference between the navigations are the parameters set to the task flows.

Here they are

Running the application we get the following output after filling in the form on the index page

WAIT, this doesn’t look right. The page with text only parameters displays the text in the footer section instead of the text section. If we look at the parameters defined for this task flow call we see

Yes, we added the value to the wrong parameter, ‘footer’ instead of ‘text’!

Easy change, we copy move it over to the ‘text’ parameter using copy and paste:

And we get

Great, this looks like it should be.

Problem(s)

WAIT again, in the log window we now get an error message

<oracle.adf.model> <ValueMappingXmlImpl> <parse> 
   <ADFc: /WEB-INF/adfc-config.xml: Failed to parse element input-parameter: null value found for value.>

Why’s that?

If you look closely at the parameters, you’ll notice, that the ‘footer’ value is empty, whereas the other not set values showing a ‘-’. So we add the ‘-’ to the footer parameter:

To get this output running the app:

The error message in the log window is gone 🙂

Hm, but now we see the ‘-’ for the footer value. The value for the ‘title’ parameter looks identical to the parameter ‘footer’. However, we don’t see the ‘-’ for the ‘title’ in GUI.

Solution

Looking at the XML of the task flow call shows:

Now the problem is, that JDeveloper shows a ‘-’ for a parameter which is not set in the XML representation, meaning that the parameter is not in the XML structure at all!

The ‘-’ we typed into the ‘footer’ parameter is visible as value for the parameter and thus it printed when running the application.

The final solution is to remove the ‘footer’ parameter from the XML structure:

This will get us the following display in JDeveloper

The resulting running page now looks like

And we don’t see the error message in the log.

Sample Download

You can download the final application from GitHub BlogTaskFlowParameter. The sample was built using JDeveloper 12.2.1.3.0 and doesn’t need a DB connection.