Wednesday, 6 June 2012

ZK MVVM CRUD - Part 3



Previous Part 2



In Part 2, we slightly change the retrieve of  objects by adding constructor. Now we will move forward. Let us take a look on the output as follows
image
Apart from the listing the records, we also have two search parameters such as Practice name and Show only active or inactive practices. So what we are going to do with this ? Well, if the list is big, then user has to move to particular page to locate the desired practice, instead of that we will filter the practice as soon as user starts typing the first few characters of the practice name. And also, by default we will show all the active (soft delete) records. If the user want to see all the records including deactivated, then on click of check box, we will also do that.
So here are the conditions
Case 1:
If no character present in the Practice name filter text area and also Show only active is unchecked, then let us show all the records from the DB.

Case 2:
If some characters are typed in the practice name filter and check box is  unchecked, then show all active and inactive records for the practice whose first characters are matched with the filter text

Case 3:
If no character in practice name filter text area and check box is checked, then we will show all the active practices only.

Case 4:
If both the search parameters contains values, then we will retrieve the records accordingly.

And also, we are going to Apply new ZK Bind Annotation such as @NotifyChange and @Command. Please refer here for examples in this subject. 
And also very important, we are not going hit the database for each character is typed or check box is checked or unchecked. First time we will hit the DB to bring the records and then we will do all the filter locally.
Step 1:
From the View, we need to pass the value of Practice name text area and Check box state (checked or unchecked)  to the View Model to filter the record. So we will write the following getter and setter method.
private String practiceStartWith;
private boolean showOnlyActive;

public String getPracticeStartWith() {
        return practiceStartWith;
    }
    public void setPracticeStartWith(String practiceStartWith) {
        this.practiceStartWith = practiceStartWith;
    }
    public boolean isShowOnlyActive() {
        return showOnlyActive;
    }
    public void setShowOnlyActive(boolean showOnlyActive) {
        this.showOnlyActive = showOnlyActive;
    }

Step 2:

Here is the modified PracticeVM.Java
package UIVMs;

import domain.Practice;
import java.util.ArrayList;
import java.util.List;
import org.zkoss.bind.annotation.Command;
import org.zkoss.bind.annotation.NotifyChange;
import DomainDAO.practiceDAO;

public class PracticeListVM {

    private List<Practice> AllPracticeInDB = null;
    private List<Practice> filteredPractices = null;

    private String practiceStartWith;
    private boolean showOnlyActive = true;

    public String getPracticeStartWith() {
        return practiceStartWith;
    }

    public void setPracticeStartWith(String practiceStartWith) {
        this.practiceStartWith = practiceStartWith;
    }

    public boolean isShowOnlyActive() {
        return showOnlyActive;
    }

    public void setShowOnlyActive(boolean pActive) {
        this.showOnlyActive = pActive;
    }

    public List<Practice> getprlist() {
        if (AllPracticeInDB == null) {
            filteredPractices = new ArrayList<Practice>();
            AllPracticeInDB = new practiceDAO().getListingItems();
            setShowOnlyActive(true);
            for (Practice item : AllPracticeInDB) {
                if (item.getIsActive() == 1)
                    filteredPractices.add(item);
            }
        }

        return filteredPractices;
    }

    @NotifyChange("prlist")
    @Command
    public void doFilter() {

        filteredPractices.clear();

        /* if no filter characters and check box is un checked. Then get all */
        /* 0 and 0 */

        if ((practiceStartWith == null || "".equals(practiceStartWith))
                && (showOnlyActive == false)) {
            filteredPractices.addAll(AllPracticeInDB);

        }

        /*
         * if there are filter characters and check box is un checked. Then get
         * filtered by filter text
         */
        /* 1 and 0 */

        if ((practiceStartWith != null && !practiceStartWith.equals(""))
                && (showOnlyActive == false)) {
            for (Practice item : AllPracticeInDB) {
                if (item.getPracticeName().toLowerCase()
                        .indexOf(practiceStartWith.toLowerCase()) == 0)
                    filteredPractices.add(item);
            }
        }

        /*
         * if no filter characters and check box is checked. Then get only
         * active practices
         */
        /* 0 and 1 */

        if ((practiceStartWith == null || "".equals(practiceStartWith))
                && (showOnlyActive == true)) {
            for (Practice item : AllPracticeInDB) {
                if (item.getIsActive() == 1)
                    filteredPractices.add(item);
            }
        }

        /*
         * Both Contains values i.e filter contains some text and check box is
         * checked
         */
        /* 1 and 1 */

        if ((practiceStartWith != null && !practiceStartWith.equals(""))
                && (showOnlyActive == true)) {
            for (Practice item : AllPracticeInDB) {
                if (item.getPracticeName().toLowerCase()
                        .indexOf(practiceStartWith.toLowerCase()) == 0)
                    if (item.getIsActive() == 1)
                        filteredPractices.add(item);
            }

        }

    }
}


Step 3:


Here is the modified practiceList.zul

<?page title="Practice List" contentType="text/html;charset=UTF-8"?>
<zk>

    <window apply="org.zkoss.bind.BindComposer"
        viewModel="@id('vm') @init('UIVMs.PracticeListVM')">
        <div>
            <button label="Add Practice" />
        </div>
        <separator />
        <groupbox height="40px">
            <label value="Practice Name" />
            <space />
            <space />
            <textbox width="250px"
                value="@bind(vm.practiceStartWith)"
                onChange="@command('doFilter')" instant="true" />
            <button id="gobutton" label="Go" />
            <space spacing="20px" />
            <checkbox id="activechk" label="Show only active"
                checked="@bind(vm.showOnlyActive)" onCheck="@command('doFilter')" />
            <space spacing="20px" />
        </groupbox>
        <separator />
        <listbox id="PracticeList" model="@load(vm.prlist)">
            <listhead sizable="true">
                <listheader label="Practice Name" sort="auto" />
                <listheader label="City" sort="auto" />
                <listheader label="State" sort="auto" />
                <listheader label="Zip Code" sort="auto" />
            </listhead>
            <template name="model" var="p1">
                <listitem>
                    <listcell label="@load(p1.practiceName)" />
                    <listcell label="@load(p1.city)" />
                    <listcell label="@load(p1.state)" />
                    <listcell label="@load(p1.zipCode)" />
                </listitem>
            </template>

        </listbox>
    </window>
</zk>



Step 4:


Now we can run and play around both practice name filter and check box.
The following is the execution flow

1. An Instance will be created for our PracticeListVM
2. Since we declared true value initially for showonlyactive, and also we bind our checkbox with showactiveonly, so first set method of showonlyactive will take place.
3. Then our getprList  will take place because we bind our list to this get method.






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