Vaadin 14 Error: cannot infer type arguments for com.vaadin.flow.data.rende

General
1

I’m trying to iterate over a HashMap to display the content in Vaadin14 Grid to look like this:

that’s the java class:

public class MyClass extends VerticalLayout {

    // Dummy Data
    LocalDate date1 = LocalDate.now();
    LocalDate date2 = LocalDate.now();
    LocalDate date3 = LocalDate.now();
    Boolean[] isPresent1 = {true, false, false, true, true, false, false, true, true};
    Boolean[] isPresent2 = {true, false, false, true, true, false, false, true, true};
    Boolean[] isPresent3 = {true, false, false, true, true, false, false, true, true};

    Map<LocalDate, Boolean[]> trainingsMap = new HashMap<>();

    Grid<Map.Entry<LocalDate, Boolean[]>> grid = new Grid<>();

    Icon icon;

    public MyClass() {
        // in reality data come from Spring Data - Repository - Service
        trainingsMap.put(date1, isPresent1);
        trainingsMap.put(date2, isPresent2);
        trainingsMap.put(date3, isPresent3);

        for (Map.Entry<LocalDate, Boolean[]> map : trainingsMap.entrySet()) {
            grid.addColumn(new ComponentRenderer<Component, Map<LocalDate, Boolean[]>>(createIsPresent(map.getValue())));
                   // .setHeaderRenderer(new LocalDateTimeRenderer<>(map.getKey(), "dd/MM HH:mm:ss"))); // 
        }

        grid.setItems(trainingsMap.entrySet());
        add(grid);
    }

    private Component createIsPresent(Boolean[] isPresent) {
        for (Boolean b : isPresent) {
            if (b) {
                icon = UIUtils.createPrimaryIcon(VaadinIcon.CHECK);
            }
        }
        return icon;
    }

}

Error: Cannot resolve constructor com.vaadin.flow.data.renderer.ComponentRenderer<>

Is this possible at all or am I doing something fundamentally wrong?

2

Have you tried it with the arguments Component, Map<LocalDate, Boolean> ?

i.e.

        for (Map.Entry<LocalDate, Boolean[]> map : trainingsMap.entrySet()) {
            grid.addColumn(new ComponentRenderer<Comnponent, Map<LocalDate, Boolean[]>>(createIsPresent(map.getValue()))
                    .setHeaderRenderer(new LocalDateTimeRenderer<>(map.getKey(), "dd/MM HH:mm:ss")));
        }

S.

3

Thanks Stuart,
I make some changes in code (including your recommendation) but now this error:

Error: Cannot resolve constructor com.vaadin.flow.data.renderer.ComponentRenderer<>

4

post you code :slight_smile:

5

Stuart Robinson:

post you code :slight_smile:


package com.ui.views.menu;

import com.ui.MainLayout;
import com.ui.util.UIUtils;
import com.vaadin.flow.component.Component;
import com.vaadin.flow.component.grid.Grid;
import com.vaadin.flow.component.icon.Icon;
import com.vaadin.flow.component.icon.VaadinIcon;
import com.vaadin.flow.component.orderedlayout.VerticalLayout;
import com.vaadin.flow.data.renderer.ComponentRenderer;
import com.vaadin.flow.data.renderer.LocalDateTimeRenderer;
import com.vaadin.flow.router.PageTitle;
import com.vaadin.flow.router.Route;

import java.time.LocalDate;
import java.util.HashMap;
import java.util.Map;

@Route(value = "erwachseneListe", layout = MainLayout.class)
@PageTitle("erwachseneListe")

//@Secured(Role.ADMIN)

public class ErwachseneListe extends VerticalLayout {

    // Dummy Data
    LocalDate date1 = LocalDate.now();
    LocalDate date2 = LocalDate.now();
    LocalDate date3 = LocalDate.now();
    Boolean[] isPresent1 = {true, false, false, true, true, false, false, true, true};
    Boolean[] isPresent2 = {true, false, false, true, true, false, false, true, true};
    Boolean[] isPresent3 = {true, false, false, true, true, false, false, true, true};

    Map<LocalDate, Boolean[]> trainingsMap = new HashMap<>();

    Grid<Map.Entry<LocalDate, Boolean[]>> grid = new Grid<>();

    Icon icon;

    public ErwachseneListe() {
        // in reality data come from Spring Data - Repository - Service
        trainingsMap.put(date1, isPresent1);
        trainingsMap.put(date2, isPresent2);
        trainingsMap.put(date3, isPresent3);

        for (Map.Entry<LocalDate, Boolean[]> map : trainingsMap.entrySet()) {
            grid.addColumn(new ComponentRenderer<Component, Map<LocalDate, Boolean[]>>(createIsPresent(map.getValue())));
                   // .setHeaderRenderer(new LocalDateTimeRenderer<>(map.getKey(), "dd/MM HH:mm:ss"))); //
        }

        grid.setItems(trainingsMap.entrySet());
        add(grid);
    }

    private Component createIsPresent(Boolean[] isPresent) {
        for (Boolean b : isPresent) {
            if (b) {
                icon = UIUtils.createPrimaryIcon(VaadinIcon.CHECK);
            }
        }
        return icon;
    }

}
6

Ok, it needs to look like this…

for (Map.Entry<LocalDate, Boolean[]> map : trainingsMap.entrySet()) {
    grid1.addColumn(new ComponentRenderer<Component, Map.Entry<LocalDate, Boolean[]>>(entry -> createIsPresent(entry.getValue())));
	// .setHeaderRenderer(new LocalDateTimeRenderer<>(map.getKey(), "dd/MM HH:mm:ss"))); //
}

Stuart

7

Thanks Stuart, maybe is possible to put a HashMap into a non Bean grid but I think is not possible to inserted also the “Person” in the first column, so I will try another way (Polymer 3) to do this.

8

You could use a ValueProvider and pass the ‘person’ object and return person.getUsername();

Stuart.

9

try and you will see what is not possible to have Grid<Person> and Grid<Map.Entry<LocalDate, Boolean[]>> in the same view.

10

Could you structure your data like this…

 Map.Entry<Person, Map.Entry<LocalDate, Boolean[]>>>

 Grid<Map.Entry<Person, Map.Entry<LocalDate, Boolean[]>>> grid = new Grid<>();

Stuart

11

I try but it doesn’t work to show the data like above.

Did you try to execute the cod?