React props - 如果另一个prop为null/empty,则在prop上设置isRequired

Question

我有一个组件<Button>.
如果组件没有this.props.children,我想将prop设置ariaLabel为isRequired,否则可以是可选的.我怎么做？

ariaLabel 道具不需要:

<Button>Add to bag</Button>

---

ariaLabel 必须要求道具:

<Button ariaLabel="Add to bag" icon={ favorite } />

---

if this.props.children和this.props.ariaLabel是空的,它会抛出一个错误,说this.props.ariaLabel是的isRequired

<Button icon={ favorite } />

---

propTypes:

Button.propTypes = {
    /** icon inside Button. */
    icon: React.PropTypes.object,
    /** Content inside button */
    children: React.PropTypes.node,
    /** Aria-label to screen readers */
    ariaLabel: React.PropTypes.string, /*isRequired if children is empty */
};

谢谢

Answer 1

你不需要另一个库,'prop-types'提供了这个开箱即用的功能.请参阅https://facebook.github.io/react/docs/typechecking-with-proptypes.html

例:

import PropTypes from 'prop-types';

//.......    

ExampleComponent.propTypes = {
    showDelete: PropTypes.bool,
    handleDelete: function(props, propName, componentName) {
        if ((props['showDelete'] == true && (props[propName] == undefined || typeof(props[propName]) != 'function'))) {
            return new Error('Please provide a handleDelete function!');
        }
    },

}

Answer 2

这可能正是您所需要的:https://github.com/thejameskyle/react-required-if

在您的情况下,您的propTypes将是:

import requiredIf from 'react-required-if';

Button.propTypes = {
    /** icon inside Button. */
    icon: React.PropTypes.object,
    /** Content inside button */
    children: React.PropTypes.node,
    /** Aria-label to screen readers */
    ariaLabel: requiredIf(React.PropTypes.string, props => !props.children), /*isRequired if children is empty */
};

Answer 3

要添加到上述@chickenchilli的答案中，您可以将其抽象为一个更方便的辅助函数，如下所示：

conditionalPropType.js

export default function conditionalPropType(condition, message) {
  if(typeof condition !== 'function') throw "Wrong argument type 'condition' supplied to 'conditionalPropType'";
  return function(props, propName, componentName) {
    if (condition(props, propName, componentName)) {
      return new Error(`Invalid prop '${propName}' '${props[propName]}' supplied to '${componentName}'. ${message}`);
    }
  }
}

MyComponent.js

import PropTypes from 'prop-types';
import conditionalPropType from './conditionalPropType';

[...]

MyComponent.propTypes = {
  conditionProp: PropTypes.bool,
  dependentProp: conditionalPropType(props => (props.condition && typeof(props.someProp) !== 'boolean'), "'dependentProp' must be boolean if 'conditionProp' is true"),
};