documented events and option

Author: fieg

docs/events.md

@@ -63,6 +63,14 @@ Triggered when the user has hit the scroll threshold for the next page due to sc
 | :--- | :--- | :--- |
 | distance | int | The distance to the scroll threshold in pixels |
 
+### top
+
+Triggered when the user has hit the top of the scroll area for the previous page due to scrolling or resizing.
+
+| property | type | description                            |
+| :--- | :--- |:---------------------------------------|
+| distance | int | The distance to the scroll top in pixels |
+
 ### next
 
 Triggered right after the `hit` event. Indicating that the next page will be loaded.
@@ -93,6 +101,36 @@ Trigger when loading and appending the next page is completed.
 | :--- | :--- | :--- |
 | pageIndex | int | The page index of the next page (the page that is finished loading) |
 
+### prev
+
+Triggered right after the `top` event. Indicating that the previous page will be loaded.
+
+| property | type | description |
+| :--- | :--- | :--- |
+| pageIndex | int | The page index of the next page (the page that is about to be loaded) |
+
+> pageIndex is zero indexed. This means the index starts at 0 on the first page.
+
+For example to notify the user about loading the next page, you can do:
+
+```js
+ias.on('prev', function(event) {
+  // pageIndex is 0-indexed, so we add 1
+  alert(`Page ${event.pageIndex+1} is loading...`);
+});
+ias.on('preved', function(event) {
+    alert(`Page ${event.pageIndex+1} is loaded and prepended to the page.`);
+});
+```
+
+### preved
+
+Trigger when loading and prepending the previous page is completed.
+
+| property | type | description |
+| :--- | :--- | :--- |
+| pageIndex | int | The page index of the next page (the page that is finished loading) |
+
 ### load
 
 This event is triggered before the next page is requested from the server.
@@ -158,18 +196,49 @@ This event is triggered after the items have been appended.
 | items | array | Array of items that have been appended |
 | parent | Element | The element to which the items have been appended |
 
+### prepend
+
+This event is triggered before the items are about to be prepended.
+
+| property | type | description                                      |
+| :--- | :--- |:-------------------------------------------------|
+| items | array | Array of items that will be prepended            |
+| parent | Element | The element to which the items will be prepended |
+| prependFn | function | Function used to append items to the container   |
+
+See [src/append.js](../src/append.js) for the default append function.
+
+### prepended
+
+This event is triggered after the items have been prepended.
+
+| property | type | description                                        |
+| :--- | :--- |:---------------------------------------------------|
+| items | array | Array of items that have been prepended            |
+| parent | Element | The element to which the items have been prepended |
+
 ### last
 
 Triggered when the last page is appended.
 
 ```javascript
 ias.on('last', () => {
-  console.log('Users has reached the last page');
+  console.log('User has reached the last page');
 })
 ```
 
 [Read more on how we can inform the user about reaching the last page](advanced/last-page-message.md)
 
+### first
+
+Triggered when the last page is appended.
+
+```javascript
+ias.on('first', () => {
+  console.log('User has reached the first page');
+})
+```
+
 ### page
 
 Triggered when the user scrolls past a page break. The event provides information about the page in view.

docs/options.md

@@ -44,6 +44,24 @@ let ias = new InfiniteAjaxScroll(/*..*/, {
 })
 ```
 
+## prev
+
+**Type:** `string`<br>
+**Default:** `undefined`<br>
+**Required:** no
+
+Selector of the previous link. The `href` attribute will be used for the url of the previous page. Only a single element should match this selector.
+
+```html
+<a href="/page/1" class="pager__prev">Prev</a>
+```
+
+```javascript
+let ias = new InfiniteAjaxScroll(/*..*/, {
+  prev: '.pager__prev'
+})
+```
+
 ## pagination
 
 **Type:** `boolean|string|Element`<br>