jwebmp-core

name: jwebmp-core description: Strongly-typed HTML/CSS/JS component model for Java — the heart of JWebMP. Provides typed HTML elements, CSS builder, server-driven events, dual rendering (HTML/JSON), CRTP fluent API, and page configurators. Use when working with JWebMP Core features, HTML component creation, CSS styling, event handling, page configuration, or any JWebMP page/component development tasks. metadata: short-description: JWebMP Core framework development

JWebMP Core

Comprehensive guide for working with JWebMP Core — the strongly-typed HTML/CSS/JS component model for Java.

Core Concepts

Dual Rendering Modes

Every JWebMP component serves dual purposes:

• toString(true) renders as HTML with all queued CSS/JS
• toString() renders as JSON for AJAX/API responses

Component Hierarchy (CRTP Pattern)

JWebMP uses an 11-layer CRTP (Curiously Recurring Template Pattern) chain:

ComponentBase → ComponentHierarchyBase → ComponentHTMLBase →
ComponentHTMLAttributeBase → ComponentHTMLOptionsBase → ComponentStyleBase →
ComponentThemeBase → ComponentDataBindingBase → ComponentDependencyBase →
ComponentFeatureBase → ComponentEventBase → Component → Your subclass

Quick Start

Creating a Simple Page

Page<?> page = new Page<>();
Div<?, ?, ?> container = new Div<>();
container.add(new Paragraph<>().setText("Welcome to JWebMP"));
page.getBody().add(container);

String html = page.toString(true);  // Full HTML
String json = page.toString();      // JSON representation

Serving with Vert.x (Optional)

@PageConfiguration(url = "/")
public class HomePage extends Page<HomePage> {
    public HomePage() {
        getBody().add(new H1<>().setText("Hello from JWebMP"));
    }
}

Register in module-info.java:

provides com.jwebmp.core.services.IPage with my.app.HomePage;

Event Handling

Events must be named classes (no lambdas/anonymous inner classes):

public class ButtonClickEvent extends OnClickAdapter {
    public ButtonClickEvent(Component component) {
        super(component);
    }

    @Override
    public void onClick(AjaxCall<?> call, AjaxResponse<?> response) {
        response.addComponent(new Paragraph<>().setText("Clicked!"));
    }
}

// Attach to component
button.addEvent(new ButtonClickEvent(button));

CSS Styling

Div<?, ?, ?> styled = new Div<>();
styled.getCss()
      .getBackground().setBackgroundColor$(ColourNames.AliceBlue);
styled.getCss()
      .getBorder().setBorderWidth(new MeasurementCSSImpl(1, MeasurementTypes.Pixels));
styled.getCss()
      .getFont().setFontSize(new MeasurementCSSImpl(14, MeasurementTypes.Pixels));

Feature System

Features must be named classes:

public class TooltipFeature extends Feature<TooltipOptions, TooltipFeature> {
    public TooltipFeature(IComponentHierarchyBase<?, ?> component) {
        super("tooltip", component);
        getOptions().setPlacement("top");
    }

    @Override
    protected void assignFunctionalityToComponent() {
        addQuery(getComponent().asBase().getJQueryID() + "tooltip(" + getOptions() + ");");
    }
}

HTML Elements

All HTML5 elements available as typed classes:

Common Elements

• Div, Span, Paragraph (flow content)
• H1–H6 (headings)
• Table, TableRow, TableHeaderCell, TableDataCell
• Form, Input* (22 typed input variants)
• Select, Option, OptionGroup
• List (ul/ol), ListItem
• Link, Image, Button

Semantic Elements

• Header, Footer, Nav, Section, Article, Aside

Input Types

• InputTextType, InputEmailType, InputNumberType, InputDateType
• InputFileType, InputCheckBoxType, InputRadioType
• And 15+ more specialized input types

Page Configuration

IPageConfigurator SPI

public class AnalyticsConfigurator implements IPageConfigurator<AnalyticsConfigurator> {
    @Override
    public IPage<?> configure(IPage<?> page) {
        page.addJavaScriptReference(new JavascriptReference("analytics", 1.0, "analytics.js"));
        return page;
    }

    @Override
    public Integer sortOrder() {
        return 500;  // After core configurators
    }
}

Register via module-info.java:

provides com.jwebmp.core.services.IPageConfigurator with my.app.AnalyticsConfigurator;

Render-Ordering SPIs

• RenderBeforeLinks / RenderAfterLinks — CSS insertion points
• RenderBeforeScripts / RenderAfterScripts — Script insertion points
• RenderBeforeDynamicScripts / RenderAfterDynamicScripts — Dynamic script points

Event System

Available Event Adapters (50+)

• OnClickAdapter, OnChangeAdapter, OnSubmitAdapter
• OnDragAdapter, OnDropAdapter
• OnKeyDownAdapter, OnKeyUpAdapter, OnKeyPressAdapter
• OnMouseEnterAdapter, OnMouseLeaveAdapter
• OnFocusAdapter, OnBlurAdapter
• And 40+ more event types

Event Service SPIs

Each event type has a corresponding ServiceLoader SPI:

• IOnClickService, IOnChangeService, IOnSubmitService, etc.

CSS Builder Packages

JPMS Module

module com.jwebmp.core {
    requires transitive com.jwebmp.client;
    requires transitive com.guicedee.client;
    requires transitive com.guicedee.vertx;
    requires transitive com.fasterxml.jackson.databind;

    exports com.jwebmp.core;
    exports com.jwebmp.core.base;
    exports com.jwebmp.core.base.html;
    exports com.jwebmp.core.base.html.inputs;
    exports com.jwebmp.core.events.*;
    exports com.jwebmp.core.htmlbuilder.css.*;

    uses IPage;
    uses IPageConfigurator;
    uses IEventConfigurator;
}

Common Patterns

Building a Form

Form<?, ?> form = new Form<>();
form.add(new Label<>().setText("Name:"));
form.add(new InputTextType<>().setName("name").setRequired(true));
form.add(new Label<>().setText("Email:"));
form.add(new InputEmailType<>().setName("email").setRequired(true));
form.add(new Button<>().setText("Submit"));
form.addEvent(new FormSubmitEvent(form));

Building a Table

Table<?, ?, ?, ?> table = new Table<>();
TableHeaderGroup<?, ?> header = new TableHeaderGroup<>();
TableRow<?, ?> headerRow = new TableRow<>();
headerRow.add(new TableHeaderCell<>().setText("Name"));
headerRow.add(new TableHeaderCell<>().setText("Email"));
header.add(headerRow);
table.add(header);

TableBodyGroup<?, ?> body = new TableBodyGroup<>();
for (User user : users) {
    TableRow<?, ?> row = new TableRow<>();
    row.add(new TableDataCell<>().setText(user.getName()));
    row.add(new TableDataCell<>().setText(user.getEmail()));
    body.add(row);
}
table.add(body);

AJAX Pipeline

public class AjaxHandler extends OnClickAdapter {
    @Override
    public void onClick(AjaxCall<?> call, AjaxResponse<?> response) {
        // Access request data
        String param = call.getParameters().get("key");

        // Modify DOM
        response.addComponent(new Div<>().setText("New content"));

        // Add reactions
        response.addReaction(new AjaxResponseReaction<>(ReactionType.REDIRECT, "/newpage"));
    }
}

Important Constraints

1. Events must be named classes — No anonymous inner classes or lambdas
2. Features must be named classes — Framework uses class identity for deduplication
3. Child constraints enforced at compile time — Type-safe component hierarchy
4. Page configurators are optional — Pages work without any configurators

Installation

<dependency>
  <groupId>com.jwebmp.core</groupId>
  <artifactId>core</artifactId>
</dependency>

Version managed by JWebMP BOM.

Key Classes

• Page — Top-level HTML page
• Component — Base for all HTML elements
• Feature — Wraps JS library with typed options
• Event — Server-driven event handler
• CSSComponent — CSS-only component (no HTML tag)
• DataAdapter — Bridges server data to JSON
• ContentSecurityPolicy — CSP header builder

References

• Module: com.jwebmp.core
• Java: 25+
• Dependencies: JWebMP Client, GuicedEE, Vert.x 5, Jackson
• License: Apache 2.0