pipe.md

nbd/util/pipe

pipe is a utility function that allows the chaining together of multiple functions, much in the manner of the pipelines in a shell.

(...filters)

pipe is used in order to produce a single function that will pass its own arguments to the first function in filters, take the result of that function, send it as the input to the next function in filters, and repeat the process until it finally returns the result of the last function in filters.

require(['nbd/util/pipe'], function(pipe) {
  function a( str ) {
    return str + ' dolor';
  }

  function b( str ) {
    return str + ' sit amet';
  }

  function c( str ) {
    return 'lorem ' + str;
  }

  // pipe produces a single function
  var ipso = pipe( a, b, c );
  typeof ipso === 'function';

  // Runs piped functions, taking result of one and handing to the next
  // Logs: lorem ipsum dolor sit amet
  console.log( ipso( 'ipsum' ) );
});

pipe is especially useful to produce a complex filter from a series of simple ones. It is also very useful for creating templating functions.

require(['nbd/util/pipe', 'jquery'], function(pipe, $) {
  function tmpl( data ) {
    return "<div id='"+data.id+"'>"+data.topic+" is "+data.value+"</div>";
  }

  // template is a function that will produce a jQuery wrapped DOM element
  var template = pipe( tmpl, $ );

  // As if calling $( tmpl( data ) );
  template({ id: 'hhgg', topic: 'Meaning of Life', value: 42 });
});

returns Function The resulting function that, when run, will return the output as returned by the last filter function.