sending notifications and emails are very important features of a facebook app. now i’m going to show how you will send notifications and emails to users.

there are two types of notifications: user-to-user and application-to-user

• a user-to-user notification is sent on behalf of one user to one or more other users
• application-to-user notifications are sent on an application’s behalf and do not require an active session.

case 1: suppose you have an application question/answer type. let user  ‘x’ sent a question to user ‘y’. so how will you notify user ‘y’ that he received a question. you can send a notification to user ‘y’ from user ‘x’ and also you could send an email to user ‘y’ from user ‘x’.

solution: for sending notification you could write this code

/*------- sends a notification or request to a set of users. notifications are items sent by an application to a user's notifications page in response to some sort of user activity within an application ----------*/
// $facebook->api_client->notifications_send(ids, notificationmessage, notificationtype);

$facebook->api_client->notifications_send('654321890', "you've received a msg from <fb:name uid='7464635353' />", 'user_to_user');

this notification is sent from user to user, that’s why you’ve to mention notification type as ‘user_to_user’

another imortant thing is that, you could send same notifications to more than one users as a single api call. just specify the ids as a comman separated list like

$facebook->api_client->notifications_send('654321890,656565654, 49393939', "msg", 'user_to_user');

case 2: let you also want to send an email to user ‘y’ from user ‘x’ in the situation of case 1.

solution: you could only send emails to the users, who have both authorized your application and granted it the email extended permission. so how will you ask the user for accepting extended permission for email. here is the way. write the below code in your view page or layout:

<fb:prompt-permission perms="email">Would you like to receive email from our application?</fb:prompt-permission>

this will render this link in your view page:

when user will click this link, a dialog box will open and show user a message  to accept receive emails permission. if user accept this permission, then this link will not shown to that user in future.

here is the api call that you have to use to send email:

//$facebook->api_client->notifications_sendEmail('recipients', 'mail_subject', "tex", 'fbml');
$facebook->api_client->notifications_sendEmail('73737373', 'you received a question', "", "hi user <fb:name uid='47363633' /> has sent you a message");

remember the parameters:

• recipients: a comma-separated list of recipient IDs. you can email up to 100 people at a time.
• subject: the subject of the email message. as of 10/28/2008, the subject will accept a limited set of fbml tags, including names, and tags related to internationalization.
• text: the plain text version of the email content. you must include a non-empty value for at least one of either the fbml or text parameters. the fbml input takes precedence, but if the given fbml value is invalid or cannot be rendered, then the text will be used instead. there is currently no character limit on the length of either the text or fbml body.
• fbml: the fbml version of the email. you must include a non-empty value for at least one of either the fbml or text parameters. the fbml parameter is a stripped-down set of fbml  that allows only html/fbml tags that result in text, links, linebreaks, as well as tags related to internationalization.

references:

• http://wiki.developers.facebook.com/index.php/Notifications.sendEmail
• http://wiki.developers.facebook.com/index.php/Notifications.send
• http://wiki.developers.facebook.com/index.php/Fb:prompt-permission

for 1 of my facebook application, i was  needed a custom friends selector. the purpose was, i’ve a page from where i’ve to select multiple friends and then i’ll submit those selected friend ids using ajax call without refreshing the page.

then i searched the documentation of fbml. in facebook component, there are 2 types of friends selector

1. http://wiki.developers.facebook.com/index.php/Fb:multi-friend-selector
2. http://wiki.developers.facebook.com/index.php/Fb:multi-friend-selector_(condensed)

but both of these are totally controlled by facebook and these components are used to send invitation or request to friends. i need a component like figure 2. the fbml code for the second component is below:

<fb:request-form method=”post” action=”http://yourdomain.com/submit.php” content=”Select Friends” type=”gifts” invite=”true”>
<div class=”clearfix” style=”padding-bottom: 10px;”>
<fb:multi-friend-selector condensed=”true” selected_rows=”0? style=”width: 220px;” />
</div>
<fb:request-form-submit />
</fb:request-form>

but I was needed a component that would be fully controlled by me. so,  I developed a friends selection component and I’m sharing it.

here is the outlook of my component:

download custom friends selector for facebook application

there are 3 parts in this code:

1. first part is css
2. second part is javascript
3. third part is html + php

so changed the file extension to .php

Here is the first part:

<style>

div.scroll {
height: 160px;
width: 200px;
overflow: auto;
border: 1px solid #666;
padding: 8px;
}

#listwords{
border: 1px solid #BDBABD;
margin-top: 5px;
margin-left: 10px;
}

#listwords ul{
list-style: none;
margin-top: -3px;
cursor: pointer;
}

#listwords span{
color: olive;
text-decoration: none;
}

.itemselect{
background-color: #e2dfaf;
color: #650202;
}

.itemmouseover{
background-color: #FFEEBB;
color: BLACK;
}

.itemnormal{
color: BLACK;
font-family: arial;
font-size: 12px;
}

this is the css code for the outlook of my component. here in the top you’ll see a bold part. this is a very important code that creates scroll bar when list is overflow than it’s height.

now the second part and 3rd part:

<script type=”text/javascript”>
//javascript part
/*————————- Friends selection —————–*/
var friendsSelectedIds =   ”; //this is string
//send this variable to php
</code></code>

function toggleSelect(id){
var liBox   =   document.getElementById(’li’ + id);
var chkBox  =   document.getElementById(’chk’ + id);

liBox.toggleClassName(’itemselect’);
if (chkBox.getChecked()){
friendsSelectedIds  =   friendsSelectedIds.replace(id + ‘,’, ”);
chkBox.setChecked(false);
}
else{
chkBox.setChecked(true);
friendsSelectedIds += id + ‘,’;
}

return false;
}
/*============== END ====================*/

function sendFriendIds(){
if (friendsSelectedIds.length == 0){
new Dialog().showMessage(’Select friends’, ‘Please select friends!’);
return false;
}

//submit form using ajax call
var ajax                = new Ajax();
ajax.responseType       = Ajax.FBML;

ajax.ondone        = function(data){
//task u will do
}

ajax.onerror = function(){
new Dialog(Dialog.DIALOG_POP).showMessage(’Error’, ‘Loading error! Please try again!’, button_confirm = ‘Okay’);
}

var queryParams = {”ids” : friendsSelectedIds};
ajax.post(’http://yourdomain.com/submit.php’ , queryParams);

}
</script>

<!– html Part –>
<form name=’ffriends’ method=”POST” action=”" onsubmit=”return false”>
<div class=”scroll” id=”listwords”>
<?php $i=0; ?>
<ul style=’margin-left: -44px’>
<?php foreach($friends as $item){ ?>
<li id=”li<?=$item['uid']?>” class=’itemnormal’ onclick=”toggleSelect(<?=$item['uid']?>)”>
<input id=”chk<?=$item['uid']?>” type=”checkbox” /> <fb:name uid=”<?=$item['uid']?>” linked=”false” />
</li>
<?php } ?>
</ul>
</div>
<input style=”margin-left: 10px;” class=”inputsubmit” type=”Submit” value=”Send Question” onclick=”sendFriendIds()” />
</form>