如何使用curring有条件地将数据传递给函数

Question

I'm somewhat new to functional programming. Here is my current paradigm from my React app. I have a generic component into which I'm passing a function which can optionally take a placeholder argument.

<TableColumn field="effectiveDate" format={dateFormatter} sortable>Start Date</TableColumn>
<TableColumn field="endDate" format={dateFormatter("No End Date")} sortable>End Date</TableColumn> 

I believe I need to use currying to acheive my goal (which I'll speak to shortly). That being the case, I've defined dateFormatter like this:

export function dateFormatter(placeholder?: string) {
  return function (date: string) {
    const attributes: any = { value: date };
    if (placeholder) {
      attributes.placeholder = placeholder;
    }
    return <ShortDate {...attributes} />;
  };
}

Then, when I actually render my table, I loop through each record and get the value like this:

getRecordValue(record: any, column: React.ReactElement<TableColumnProps>) {
    const { format, field } = column.props;
    const cell = field ? record[field] : "";
    if (format) {
      return format()(cell, record);
    }
    return cell;
}

I want to have a single dateFormatter function, but be able to optionally pass a placeholder and defer execution. How can I do this?

Answer 1

just use props. Check if the parrent has passed certain props, in your case is format .

class App extends React.component{
  render(){
     <CustomComponent  format={dateFormatter("No End Date")}/>
  }
}

class CustomComponent extends React.component{
  constructor(props){
    super(props)
  }

  render(){
     <div>
       Your content maybe
       { this.props.format && this.props.format }
     </div>
  }
}