Adding "precondition" option

README.md

@@ -82,6 +82,7 @@ Ouibounce offers a few options, such as:
 - [Aggressive mode](#aggressive-mode)
 - [Timer](#set-a-min-time-before-ouibounce-fires)
 - [Delay](#delay)
+- [Precondition](#precondition)
 - [Callback](#callback)
 - [Cookie expiration](#cookie-expiration)
 - [Cookie domain](#cookie-domain)
@@ -125,6 +126,19 @@ _Example:_
 ouibounce(document.getElementById('ouibounce-modal'), { delay: 100 });
 ```
 
+##### Precondition
+You can add a precondition, which is a function that will run once Ouibounce has been triggered, by using the `precondition` option.
+The precondition allow you to prevent Ouibouce to show the modal if you don't want to.
+
+_Example:_    
+```js
+ouibounce(document.getElementById('ouibounce-modal'), { precondition: function() { 
+    console.log('Should Ouibounce be fired?'); }
+    return true; // Ouibounce is not fired if false
+});
+```
+
+
 ##### Callback
 You can add a callback, which is a function that will run once Ouibounce has been triggered, by using the `callback` option.
 

build/ouibounce.js

@@ -24,7 +24,8 @@ return function ouibounce(el, custom_config) {
     cookieName   = config.cookieName ? config.cookieName : 'viewedOuibounceModal',
     sitewide     = config.sitewide === true ? ';path=/' : '',
     _delayTimer  = null,
-    _html        = document.documentElement;
+    _html        = document.documentElement,
+    preConditionCallback = config.precondition;
 
   function setDefault(_property, _default) {
     return typeof _property === 'undefined' ? _default : _property;
@@ -96,6 +97,8 @@ return function ouibounce(el, custom_config) {
   function fire() {
     if (isDisabled()) { return; }
 
+    if (preConditionCallback && typeof preConditionCallback === 'function' && !preConditionCallback()) { return; }
+
     if (el) { el.style.display = 'block'; }
 
     callback();

source/ouibounce.js

@@ -12,7 +12,8 @@ function ouibounce(el, custom_config) {
     cookieName   = config.cookieName ? config.cookieName : 'viewedOuibounceModal',
     sitewide     = config.sitewide === true ? ';path=/' : '',
     _delayTimer  = null,
-    _html        = document.documentElement;
+    _html        = document.documentElement,
+    preConditionCallback = config.precondition;
 
   function setDefault(_property, _default) {
     return typeof _property === 'undefined' ? _default : _property;
@@ -84,6 +85,8 @@ function ouibounce(el, custom_config) {
   function fire() {
     if (isDisabled()) { return; }
 
+    if (preConditionCallback && typeof preConditionCallback === 'function' && !preConditionCallback()) { return; }
+
     if (el) { el.style.display = 'block'; }
 
     callback();