package com.jarch.showcase.view.data.datatable;

import java.io.Serializable;
import javax.annotation.PostConstruct;
import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ManagedProperty;
import javax.faces.bean.ViewScoped;
import javax.faces.context.FacesContext;
import org.primefaces.event.SelectEvent;
import org.primefaces.model.LazyDataModel;
import org.primefaces.showcase.domain.Car;
import org.primefaces.showcase.service.CarService;

@ManagedBean(name="dtLazyView")
@ViewScoped
public class LazyView implements Serializable {
    
    private LazyDataModel<Car> lazyModel;
    
    private Car selectedCar;
    
    @ManagedProperty("#{carService}")
    private CarService service;
    
    @PostConstruct
    public void init() {
        lazyModel = new LazyCarDataModel(service.createCars(200));
    }

    public LazyDataModel<Car> getLazyModel() {
        return lazyModel;
    }

    public Car getSelectedCar() {
        return selectedCar;
    }

    public void setSelectedCar(Car selectedCar) {
        this.selectedCar = selectedCar;
    }
    
    public void setService(CarService service) {
        this.service = service;
    }
    
    public void onRowSelect(SelectEvent event) {
        FacesMessage msg = new FacesMessage("Car Selected", ((Car) event.getObject()).getId());
        FacesContext.getCurrentInstance().addMessage(null, msg);
    }
}

                

package com.jarch.showcase.service;

import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import javax.faces.bean.ApplicationScoped;
import javax.faces.bean.ManagedBean;
import org.primefaces.showcase.domain.Car;

@ManagedBean(name = "carService")
@ApplicationScoped
public class CarService {
    
    private final static String[] colors;
	
	private final static String[] brands;
    
    static {
		colors = new String[10];
		colors[0] = "Black";
		colors[1] = "White";
		colors[2] = "Green";
		colors[3] = "Red";
		colors[4] = "Blue";
		colors[5] = "Orange";
		colors[6] = "Silver";
		colors[7] = "Yellow";
		colors[8] = "Brown";
		colors[9] = "Maroon";
		
		brands = new String[10];
		brands[0] = "BMW";
		brands[1] = "Mercedes";
		brands[2] = "Volvo";
		brands[3] = "Audi";
		brands[4] = "Renault";
		brands[5] = "Fiat";
		brands[6] = "Volkswagen";
		brands[7] = "Honda";
		brands[8] = "Jaguar";
		brands[9] = "Ford";
	}
    
    public List<Car> createCars(int size) {
        List<Car> list = new ArrayList<Car>();
		for(int i = 0 ; i < size ; i++) {
			list.add(new Car(getRandomId(), getRandomBrand(), getRandomYear(), getRandomColor(), getRandomPrice(), getRandomSoldState()));
        }
        
        return list;
    }
    
    private String getRandomId() {
		return UUID.randomUUID().toString().substring(0, 8);
	}
    
    private int getRandomYear() {
		return (int) (Math.random() * 50 + 1960);
	}
	
	private String getRandomColor() {
		return colors[(int) (Math.random() * 10)];
	}
	
	private String getRandomBrand() {
		return brands[(int) (Math.random() * 10)];
	}
    
    public int getRandomPrice() {
		return (int) (Math.random() * 100000);
	}
    
    public boolean getRandomSoldState() {
		return (Math.random() > 0.5) ? true: false;
	}

    public List<String> getColors() {
        return Arrays.asList(colors);
    }
    
    public List<String> getBrands() {
        return Arrays.asList(brands);
    }
}
                

package com.jarch.showcase.view.data.datatable;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.primefaces.model.LazyDataModel;
import org.primefaces.model.SortOrder;
import org.primefaces.showcase.domain.Car;

/**
 * Dummy implementation of LazyDataModel that uses a list to mimic a real datasource like a database.
 */
public class LazyCarDataModel extends LazyDataModel<Car> {
    
    private List<Car> datasource;
    
    public LazyCarDataModel(List<Car> datasource) {
        this.datasource = datasource;
    }
    
    @Override
    public Car getRowData(String rowKey) {
        for(Car car : datasource) {
            if(car.getId().equals(rowKey))
                return car;
        }

        return null;
    }

    @Override
    public Object getRowKey(Car car) {
        return car.getId();
    }

    @Override
    public List<Car> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String,Object> filters) {
        List<Car> data = new ArrayList<Car>();

        //filter
        for(Car car : datasource) {
            boolean match = true;

            if (filters != null) {
                for (Iterator<String> it = filters.keySet().iterator(); it.hasNext();) {
                    try {
                        String filterProperty = it.next();
                        Object filterValue = filters.get(filterProperty);
                        String fieldValue = String.valueOf(car.getClass().getField(filterProperty).get(car));

                        if(filterValue == null || fieldValue.startsWith(filterValue.toString())) {
                            match = true;
                    }
                    else {
                            match = false;
                            break;
                        }
                    } catch(Exception e) {
                        match = false;
                    }
                }
            }

            if(match) {
                data.add(car);
            }
        }

        //sort
        if(sortField != null) {
            Collections.sort(data, new LazySorter(sortField, sortOrder));
        }

        //rowCount
        int dataSize = data.size();
        this.setRowCount(dataSize);

        //paginate
        if(dataSize > pageSize) {
            try {
                return data.subList(first, first + pageSize);
            }
            catch(IndexOutOfBoundsException e) {
                return data.subList(first, first + (dataSize % pageSize));
            }
        }
        else {
            return data;
        }
    }
}
                

package com.jarch.showcase.view.data.datatable;

import java.util.Comparator;
import org.primefaces.model.SortOrder;
import org.primefaces.showcase.domain.Car;

public class LazySorter implements Comparator<Car> {

    private String sortField;
    
    private SortOrder sortOrder;
    
    public LazySorter(String sortField, SortOrder sortOrder) {
        this.sortField = sortField;
        this.sortOrder = sortOrder;
    }

    public int compare(Car car1, Car car2) {
        try {
            Object value1 = Car.class.getField(this.sortField).get(car1);
            Object value2 = Car.class.getField(this.sortField).get(car2);

            int value = ((Comparable)value1).compareTo(value2);
            
            return SortOrder.ASCENDING.equals(sortOrder) ? value : -1 * value;
        }
        catch(Exception e) {
            throw new RuntimeException();
        }
    }
}