html - Updating value which depends on changing of another value, and vice versa -

i have kind of problem. can't find solution on web. have value depends on modification of value. , vice versa. code

<div class="panel-body">         <div class="row">             <label class="col-lg-2 label-margin"> fondo bucket 1 (eur)</label>             <div class="col-lg-1 right-col-margin">{{::fondo.fnd1}}</div> ---> input             <label class="col-lg-2 label-margin"> fondo bucket 2 (eur)</label>             <div class="col-lg-7 right-col-margin">{{::fondo.fnd2}}</div> ---> input         </div>             <div class="row">             <label class="col-lg-2 label-margin"> fondo bucket 1 (div)</label>              <div class="col-lg-1 right-col-margin">{{::fondo.fnd1div}}</div> ---> input             <label class="col-lg-2 label-margin"> fondo bucket 2 (div)</label>             <div class="col-lg-7 right-col-margin">{{::fondo.fnd2div}}</div> ---> input         </div>         <div class="row">             <label class="col-lg-2 label-margin"> bucket dh </label>             <div class="col-lg-1 right-col-margin">{{::fondo.bktdh}}</div>             <label class="col-lg-2 label-margin"> cambio </label>             <div class="col-lg-7 right-col-margin">{{::fondo.cambio}}</div>         </div>     </div> 

my wish being able edit fields fondo.fnd1, fondo.fnd2, fondo.fnd1div , fondo.fnd2div, but... if edit fondo.fnd1 , fondo.fnd2 new value of fondo.fnd1div must division between fondo.fnd1 , fondo.cambio , new value of fondo.fnd2div must division between fondo.fnd2 , fondo.cambio (i can modify 1 of these 2 fields). instead, if modify fondo.fnd1div , fondo.fnd2div new value of fondo.fnd1 must multiplication between fondo.fnd1div , cambio, , new value of fondo.fnd2div must multiplication of fondo.fnd2 , cambio. need immediate update , avoid "tragic" loop. know must use ng-change, don't know how use it. thank in advance.

there many different event listeners available in angular. in particular, there 4 main listeners can used in scenario, , each operates differently.

ng-keyup

this event used when want fire function in response user releases key. differs ng-keypress, fires when key pressed, fires continually if key held down.

ng-blur

this event used when want detect if focused input on form "blurred", or in other words, if focus changes 1 input another. fire once entire input interaction.

ng-change

this event fires whenever new value committed model. fire when change occurs model, , not fire when conditions true, such input form value being invalid or null.

note of these listeners fire under specific conditions on input fields, , none of them fire due programmatic changes model value. therefore, cannot stuck in loop changing value causes event fire causes change. happen other frameworks, changed dom directly.