react-select-option

react-select-option

Usage

Importing this library yields an object with two keys, Select and Option, roughly corresponding to the HTML <select> and <option>.

Styling

Styling of this component can be done through Javascript or CSS. However, Javascript styles are currently required to style the select container as well as the options container style.

Much of the rendering is done through a series of functional rendering delegates, which are functions that the Select component calls every time it needs to know how to render parts of the Select, such as each <Option>. These delegates are provided with arguments passed in to it by the component indicating the current state of the component.

The delegate for the <select> displaying child should be provided as a function to the displayingChildRenderer prop of the Select. This is provided three arguments, in this order:

child, the Option node to render isExpanded, whether the component is in an expanded state isFocused, whether the select is focused

Each <Select.Option> also takes a functional rendering delegate as its child. This delegate is provided with three options,

isHovering, whether we are hovering over an element without having selected it, whether with the keyboard or the mouse isActive, whether the mouse is currently down on the element, causing an active state to be produced isSelected, whether the element is the currently selected one

There may be efficiency concerns here, but in this first iteration there are no overly serious inefficiencies. When the component first mounts each <Option> renders, but after that an <Option> renders only when it is involved in a state change. For example, if you hover from one element to another, the leaving element re-renders and the entering element re-renders.

Currently, the displayingChildRenderer is the most inefficient of the bunch, and re-renders each time the menu is opened and closed, which might perhaps be fixed shortly.

Hastily Inserted Example

<Select.Select onChange={this.handleChange}
               onOptionHover={this.handleHover}
               value={this.state.value}
               displayingChildRenderer={
                (child, isExpanded, isFocused) => {
                  return <div style={{border: `4px solid ${isFocused ? '#f88' : '#555'}`}}>{child}</div>;
                }
              }
               style={{
                optionsContainerStyle: {
                  border: '1px solid #f0f'
                }
               }}>
  {exampleConstants.data.map((d, i) => {
    return <Select.Option value={d.value} label={d.label} key={d.value}>
      {(hover, active, selected) => {
        return <div className={`${exampleConstants.SELECT_CLASS_PREFIX}-${i}${selected ? '-selected' : ''}`}>
          {d.label +
          (hover ? exampleConstants.HOVERING_SYMBOL : '') +
          (active ? exampleConstants.ACTIVE_SYMBOL : '') +
          (selected ? exampleConstants.SELECTED_SYMBOL : '')}
        </div>;
      }}
    </Select.Option>;
  })}
</Select.Select>

Releasing

To release, run npm run build, npm version <type>, and then npm publish ./.

Tests

To run tests, use npm run nightwatch. You should have a Selenium server running and the example running on port 8000, which you can do by running npm run start.