Lite Renderer Add-on

[EXPERIMENTAL] A Renderer for Vaadin Flow that uses a component instance as template, intended for use as an alternative to LitRenderer.

grid.addColumn(LiteRenderer.<Person>of(
    new Button("Update", ev->handleUpdate(LiteRenderer.getItem(ev, Item.class))),
    new Button("Update", ev->handleRemove(LiteRenderer.getItem(ev, Item.class)));

Instead of:

grid.addColumn(LitRenderer.<Person>of(
     "<button @click=\"${handleUpdate}\">Update</button>" +
     "<button @click=\"${handleRemove}\">Remove</button>")
    .withFunction("handleUpdate", person -> { ... })
    .withFunction("handleRemove", person -> { ... })        
)

Features

• Use component instances as template, instead of the HTML approach used by LitRenderer.
• The component is rewritten as a lit template.

Online demo

Online demo here

Download release

Available in Vaadin Directory

Maven install

Add the following dependencies in your pom.xml file:

<dependency>
   <groupId>com.flowingcode.vaadin.addons</groupId>
   <artifactId>lite-renderer-addon</artifactId>
   <version>X.Y.Z</version>
</dependency>

Release versions are available from Maven Central repository. For SNAPSHOT versions see here.

Building and running demo

• git clone repository
• mvn clean install jetty:run

To see the demo, navigate to http://localhost:8080/

Release notes

See here

Issue tracking

The issues for this add-on are tracked on its github.com page. All bug reports and feature requests are appreciated.

Contributions

Contributions are welcome. There are two primary ways you can contribute: by reporting issues or by submitting code changes through pull requests. To ensure a smooth and effective process for everyone, please follow the guidelines below for the type of contribution you are making.

1. Reporting Bugs and Requesting Features

Creating an issue is a highly valuable contribution. If you've found a bug or have an idea for a new feature, this is the place to start.

• Before creating an issue, please check the existing issues to see if your topic is already being discussed.
• If not, create a new issue, choosing the right option: "Bug Report" or "Feature Request". Try to keep the scope minimal but as detailed as possible.

A Note on Bug Reports

Please complete all the requested fields to the best of your ability. Each piece of information, like the environment versions and a clear description, helps us understand the context of the issue.

While all details are important, the minimal, reproducible example is the most critical part of your report. It's essential because it removes ambiguity and allows our team to observe the problem firsthand, exactly as you are experiencing it.

2. Contributing Code via Pull Requests

As a first step, please refer to our Development Conventions page to find information about Conventional Commits & Code Style requirements.

Then, follow these steps for creating a contribution:

• Fork this project.
• Create an issue to this project about the contribution (bug or feature) if there is no such issue about it already. Try to keep the scope minimal.
• Develop and test the fix or functionality carefully. Only include minimum amount of code needed to fix the issue.
• For commit message, use Conventional Commits to describe your change.
• Send a pull request for the original project.
• Comment on the original issue that you have implemented a fix for it.

License & Author

This add-on is distributed under Apache License 2.0. For license terms, see LICENSE.txt.

Lite Renderer Add-On is written by Flowing Code S.A.

Developer Guide

Getting started

• Use component instances as template:

    Div template = new Div(
        new Image("${item.pictureUrl}", "Portrait of ${item.firstName} ${item.lastName}"),
        new Div("${item.firstName} ${item.lastName}"),
        new Div("${item.profession}"));

    comboBox.setRenderer(LiteRenderer.<Person>of(template)
        .withProperty("pictureUrl", Person::pictureUrl)
        .withProperty("firstName", Person::firstName)
        .withProperty("lastName", Person::lastName)
        .withProperty("profession", Person::profession));

• withAttribute and withListener are fluent methods that allow setting attributes and listeners:

    Div div = new Div("${item.firstName} ${item.lastName}");
    grid.addColumn(LiteRenderer.<Person>of(div)
        .withProperty("firstName", Person::firstName)
        .withProperty("lastName", Person::lastName)
        .withProperty("age", Person::age)
        .withAttribute(div, "tooltip", "Age: ${item.age}")
        .withAttribute(div, "style", person-> "color: "+ (person.age()<18?"red":"blue"))
        .withListener(div, "click", item -> {
          Notification.show(item.firstName() + " " + item.lastName() + " Clicked!");
        }
    ));

• Wrapping a component with LiteComponent allows fluent setters for attributes, properties, and listeners, removing the need for variables.

    Div div = new Div("${item.firstName} ${item.lastName}");
    grid.addColumn(LiteRenderer.<Person>of(div)
        .withProperty("firstName", Person::firstName)
        .withProperty("lastName", Person::lastName)
        .withProperty("age", Person::age)
        .withAttribute(div, "tooltip", "Age: ${item.age}")
        .withAttribute(div, "style", person-> "color: "+ (person.age()<18?"red":"blue"))
        .withListener(div, "click", item -> {
          Notification.show(item.firstName() + " " + item.lastName() + " Clicked!");
        }
    ));

• Listeners can also receive more data in addition to the item:

    TextField tf = new TextField();
    grid.addColumn(LiteRenderer.<Person>of(tf).withListener(tf, "change", (item, args) -> {
              Notification.show(item.firstName()
              + " " + item.lastName()
              + " says: " + args.getString(0));
    }, "event.target.value"));

• The click event of a template Button is called when the button is clicked. Within the event listener, LiteRenderer.getItem(ev, Person.class) returns the current item:

    grid.addColumn(LiteRenderer.<Person>of(new Button("Click", ev->{
      var item = LiteRenderer.getItem(ev, Person.class);
      Notification.show(item.firstName() + " " + item.lastName() + " Clicked!");
    })));

• Flow Viritin components enable more fluent method chaining:

    grid.addColumn(LiteRenderer.<Person>of(
            VSpan.of("${item.firstName} ${item.lastName}")
                 .withStyle("color", "${item.color}"))
         .withProperty("color", person->person.age()<18?"red":"blue")
         .withProperty("firstName", Person::firstName)
         .withProperty("lastName", Person::lastName));