readline-literal

Install

npm install --save readline-literal

Some information

As of version 1.3 questions that are identical only get answered once.

There was a bug in before version 1.3 where the template tag could only be used once. This is now fixed.

Example 1

//Notice the call right after the require.
const rll = require('readline-literal')();

rll`Hello ${'who? '}!`.then((result)=>{
    //You will be prompted with "who? "
    //result is the interpolated string with all of your input.
    console.log(result);
}, (err) => {
    console.log(err)
});

Example 2 - compile

src.json

{
    "val": "${'thing? '}"
}

Using the fs-promise module:

const rll = require('readline-literal')();
const fsp = require('fs-promise');


fsp.readFile('src.json', 'utf8').then((text)=>{
    return rll.compile(text);
})
.then((result)=>{
    // result =
    // '{
    //     "val": "Something you wrote."
    // }'
    console.log(result)
})
.catch((err)=>console.log(err));

Example 3 - Custom Query

const rll = require('readline-literal')();
const list = new rll.Query((answer)=>{
    return answer.split(',').map((item)=>{
        return '- ' + item.trim();
    }).join('\n');
});

rll`Items
${list.ask('Items: ')}
`.then((result)=>{
    console.log(result);
}, (err) => {
    console.log(err)
});
/*Result equals:
Items
- one
- two
*/

About

readline-literal takes a javascript string literal. The values of the literal are used to create questions for readline output in the command-line.

API

createReadlineLiteral(undefined || options) -> readlineLiteral function

The module readline-literal is a function you should call to get a readlineLiteral function.

createReadlineLiteral is the function you get when importing this module.

createReadlineLiteral can be passed an options object.

The options object can have these fields:

###options.interface = (An custom instance of readline)

When set this instance of readline will be used instead of the internal one.

options.map(answer)

If set options.map will run on every answer so you can change answers as they are input.

Return the change from options.map.

readlineLiteral(template literal) -> Promise

Process a template literal, and use it's interpolated values as questions to readline.

Call readlineLiteral as a javascript template tag.

The promise returned resolves to the interpolated string.

Template values

There are two types of values you can put in the template literal.

1. The values in the template literal passed to readlineLiteral can be a string that is turned into a question.
2. The values can also be an array of length 2 with the value at index zero being the string that is turned into a question, and the value at index 1 being a default value.

So you can do this for no default:

rll`Hello ${'who? '}!`.then((result)=>{console.log(result)});

or this to have a default value:

rll`Hello ${['who? ', 'world']}!`.then((result)=>{console.log(result)});

readlineLiteral.compile(text) -> Promise

Compile some text that looks like a template literal, and start readline right away.

Warning

readlineLiteral will quit right away (on Unix) if there is a Control+c key sequence input.

If a readline process is quit early then the Promise returned by readlineLiteral will be rejected with a value of null.