STRING-D

NodeJS String Variable Parser

Create parsable strings using template formats by argument mapping.

Similar to printf but supports nesting and exclusive recursions

Installing

Via NPM:

npm install stringd

Usage

import stringd from 'stringd';
stringd('Hello :{name}', {name: 'World'});
// Hello World
stringd(':{last}, :{first} :{last}', {last: 'Doe', first: 'John'});
// Doe, John Doe

API

stringd(template, object[, ignore])

tmp: <string>
props: <object>
ignore: <string[]>
Returns: <string>

Parse the tmp string, replacing variable sections with flexibly defined values within the props object
String tags within the ignore array are skipped in the process. (used specifically to avoid repetition/recursion)

Features

Multi parse methods

Whichever is more comfortable for you would work just fine

stringd('Hello :{name}', {name: 'World'});  // Hello World
stringd('Hello %{name}', {name: 'World'});  // Hello World
stringd('Hello ${name}', {name: 'World'});  // Hello World
stringd('Hello :{name%}', {name: 'World'}); // Hello World
stringd('Hello %{name%}', {name: 'World'}); // Hello World
stringd('Hello ${name%}', {name: 'World'}); // Hello World

Nesting

assert.equal('John Davis', stringd(':{name}', {
  name: ':{first} :{last}',
  last: 'Davis',
  first: 'John',
}));

Extended, Variable Passing

assert.equal(
  'Age Difference = [32 + 25]  = [57]',
  stringd(
    stringd('Age Difference = [:{age1} + :{age2}]  = [:{add(:{age1}, :{age2})}]', {
      age1: 32,
      age2: 25,
    }),
    {add: (_, data) => data.args.reduce((a, v) => a + +v.trim(), 0)},
  ),
);

assert.equal(
  'Hello, Guys; Hello, World. How are you doing?',
  stringd(':{greet(Guys, post=How are you doing?, World)}', {
    greet: (_, names) =>
      names.args
        .map(name => `Hello, ${name.trim()}`)
        .join('; ')
        .concat('. ', names.matched.post),
  }),
);

Functional Evaluation

assert.equal(
  'Hello John Davis, you have contributed $585 in the span of 13 months',
  stringd(':{name:parsed}', {
    name: ':{first} :{last}',
    last: 'Davis',
    first: 'John',
    greeting: 'Hello :{name}',
    months: 13,
    duration: ':{months} months',
    contribution: 45,
    // Functions get the entire template object as an argument
    // so you can do advanced processing
    cash: ({contribution, months}) => contribution * months,
    'name:parsed': `:{greeting}, you have contributed $:{cash} in the span of :{duration}`,
  })
);

Forward Padding, Space

assert.equal('   10', stringd(':5{val}', {val: 10}));

End Padding, Space

assert.equal('10   ', stringd(':-5{val}', {val: 10}));

Forward Padding, Zero

assert.equal('00010', stringd(':05{val}', {val: 10}));

End Padding, Zero

assert.equal('10000', stringd(':-05{val}', {val: 10}));

Complex Nesting with exclusive recursion

Recursive nesting is unparsed at the second level, otherwise, it continues until its done parsing the entire string

assert.equal(
  'James:{name} :{name} :{data} :{data} :{all} :{name} :{data}Jack James:{data}Jack James:{data}Jack :{misc} :{data} :{all} James:{data}Jack :{misc}',
  stringd(':{name} :{misc}', {
    name: ':{first}:{data}:{last}',
    first: 'James',
    last: 'Jack',
    misc: ':{data}',
    data: ':{name} :{all}',
    all: ':{name} :{misc} :{data} :{all} :{name} :{misc}',
  })
);

Iterative processing

assert.equal('      2364', stringd(stringd('::{pad}{price}', {pad: 10}), {price: 2364}))

Precedence

stringd replaces keys in order precedence. Keys that appear first are replaced first

stringd( // str key appears first
  stringd(':{tro:{str}}', {str: 'y', 'tro:{str}': ':{tron}'}),
  { tron: 'Movie', troy: 'Dude' }
); // Dude
stringd( // str key appears later
  stringd(':{tro:{str}}', {'tro:{str}': ':{tron}', str: 'y'}),
  { tron: 'Movie', troy: 'Dude' }
); // Movie

Development

Feel free to clone, use in adherance to the license. Pull requests are very much welcome.

git clone https://github.com/miraclx/stringd.git
cd stringd
npm install
# hack on code
npm test

Testing

Tests are executed with Jest. To use it, simple run npm install, it will install
Jest and its dependencies in your project’s node_modules directory and finally npm test.

To run the tests:

npm install
npm test