simpleWheneverJs

A javascript class that allows you to watch a value. This is a simple version which means there are some restriction when using.

API

SimpleWhenever(callback)

Please pass in a function with returning a boolean value. When you change value, this callback will be called. And it's return value will be translate to current status of the Whenever instance. (true for SimpleWhenever.status = 'resolve' and false for SimpleWhenever.status = 'reject').This call back will be SimpleWhenever.judge

yes(callback,once)

add callback to whenever, and will be execute whenever the SimpleWhenever.judge return true. If the SimpleWhenever.status == 'resolve', callback will execute right away.If once equals true, this callback will execute only once.

no(callback,once)

similar to yes but will execute when SimpleWhenever.judge return false or SimpleWhenever.status == 'reject'.

change(value)

change Whenever value.This will call SimpleWhenever.judge, and execute yes functions or no functions according to the return value.

usage


var w = new SimpleWhenever(function(value){
  return value == 1;
});
w.yes(function(){
  console.log('yes once');
},true);
w.yes(function(){
  console.log('yesyes');
});
w.no(function(){
  console.log('no once');
},true);
w.no(function(){
  console.log('nono');
});
w.change(1);
//output: yesyes
//output: yes once
//explain: once functions will execute later
w.yes(function(){
  console.log('yesyesyes once');
},true);
//output: yesyesyes once
//explain: any functions add to yes will execute right away if matches value.
w.change(2);
//output: nono
//output: no once
//explain: once functions will execute later than forever one
w.change(1);
//output: yesyes
//explain: once functions will remove after execution
w.change(2);
//output: nono
w.no(function(){
  console.log('nonono once');
},true);
//output: nonono once
//explain: any functions add to no will execute right away if do not matches value.
w.change(1);
//output: yesyes
w.change(2);
//output: nono

ahcheqiu / simpleWheneverJs