module Preact::Component::NativeComponentConstructor

Public Class Methods

extended(base) click to toggle source

for should_component_update we apply ruby semantics for comparing props to do so, we convert the props to ruby hashes and then compare this makes sure, that for example rubys Nil object gets handled properly

# File lib/preact/component/native_component_constructor.rb, line 7
def self.extended(base)
  component_name = base.to_s
  %x{
    base.preact_component = class extends Opal.global.Preact.Component {
      constructor(props) {
        super(props);
        if (base.$default_state_defined()) {
          this.state = base.$state().$to_n();
        } else {
          this.state = {};
        };
        this.__ruby_instance = base.$new(this);
        var defined_refs = #{base.defined_refs};
        for (var ref in defined_refs) {
          if (defined_refs[ref] != null) {
            this[ref] = function(element) {
              element = Opal.Preact.native_element_or_component_to_ruby(element);
              #{`this.__ruby_instance`.instance_exec(`element`, &`defined_refs[ref]`)}
            }
            this[ref] = this[ref].bind(this);
          } else {
            this[ref] = Opal.global.Preact.createRef();
          }
        }
      }
      static get displayName() {
        return #{component_name};
      }
      render(props, state) {
        const oper = Opal.Preact;
        oper.render_buffer.push([]);
        // console.log("react component pushed", oper.render_buffer, oper.render_buffer.toString());
        oper.active_components.push(this);
        let block_result = #{`this.__ruby_instance`.instance_exec(&`base.render_block`)};
        if (block_result && block_result !== nil) { oper.render_block_result(block_result); }
        // console.log("react component popping", oper.render_buffer, oper.render_buffer.toString());
        oper.active_components.pop();
        let result = oper.render_buffer.pop();
        return (result.length === 1) ? result[0] : result;
      }
      shouldComponentUpdate(next_props, next_state) {
        if (base.should_component_update_block) {
          return #{!!`this.__ruby_instance`.instance_exec(Preact::Component::Props.new(`{props: next_props}`), Preact::Component::State.new(`{state: next_state }`), &`base.should_component_update_block`)};
        }
        if (!Opal.Preact.props_are_equal(this.props, next_props)) { return true; }
        if (Opal.Preact.state_is_not_equal(this.state, next_state)) { return true; }
        return false;
      }
      validateProp(props, propName, componentName) {
        try { base.$validate_prop(propName, props[propName]) }
        catch (e) { return new Error(componentName + " Error: prop validation failed: " + e.message); }
        return null;
      }
    }
  }
end