like option in a website using codeigniter - codeigniter

Question

I have a problem like this. I am creating a website using codeigniter. In it, users can ask questions and "like" them. All questions should be shown in the website by descending Order by the amount of like. If the first questions has 20 like and the second one has 18 and then, a person likes the second question ,then it has 19 likes it should stay in same place if it got 21 likes it should come to the top.
How can i do this?
I search internet so many times but i couldn't able to find out something suitable.
This is my question table.

Answer 1

In your view you have something like that i guess:
<input type="button" class="likeAction" data-questid="<?=$question->id?>" value="Like">
In jquery, when a like button is cliked, read the value of the data(questid) and you should start an ajax query to the likeQuestion method.
I don't know your code so I just write as i do it...
In your controller :
public function likeQuestion($quest_id){
$json = (object) []; //init an object, easier to use with json
$json->result = "error";
$res = $this->question_model->like($quest_id);
if($res){
$json->result = "success";
//read the number of like of the question
$json->num_like = $this->question_model->countLikeNumber($quest_id);
}
header("Content-type:application/json");
echo json_encode($json);
}
In your model :
public function like($quest_id){
$this->db->set('likes', 'likes+1', FALSE); //the false is important here
$this->db->where('id', $quest_id);
$this->db->update('question');
}
public function countLikeNumber($quest_id){
$this->db->select('*');
$this->db->from('question');
$this->db->where("id", $quest_id);
$query = $this->db->get();
return $query->num_rows();
}

Answer 2

I'll assume that you want to send your [adding like] request via ajax, and then ordering your list according the number of likes for each question, and I'll cover basically your front-end code reading the comments, so:
Your view should be like this:
<ul class="questions">
<li id="question_item_<?= $id ?>">
...
<span id="likes_<?= $id ?>"><?= $likesNum ?></span>
<button class="likeBtn" data-id="<?= $id ?>" >Like</button>
</li>
<li id="question_item_<?= $id ?>">
...
<span id="likes_<?= $id ?>"><?= $likesNum ?></span>
<button class="likeBtn" data-id="<?= $id ?>" >Like</button>
</li>
...
</ul>
Your Ajax Call:
$('.likeBtn').click(function(){
var $clicked = $(this),
questionID = $clicked.data('id'),
likesNum = $('li#question_item_' + questionID).find('span').text;
$.ajax({
url: 'PATH_TO_YOUR_CONTROLLER_METHOD_addingLike',
data: {'question_id': questionID},
dataType: 'json',
success: function(returnedData){
if(returnedData.status === 'success'){
$('li#question_item_' + questionID).find('span').text(parseInt(likesNum ) + 1);
reorderQuestions(returnedData.ids);
}
},
error: function(error){
console.log(error.resposeText);
}
});
});
/* Reordering your list at the front-end base,
* preventing server resources highly consumptions
*/
function reorderQuestions(ids){
var newUL = $('<ul class="questions">');
$each(ids, function(index, id){
newUL.append($('li#question_item_' + id));
});
$('ul.questions')replaceWith(newUL);
}
Your Controller Should behave like this:
public function addingLike($question_id){
# Increasing the number of like for question holding the specific id,
# Fetching all your questions ids ordered by the number of its likes
# Return a json object ['status': success, 'ids': [array_of_ids_ordered_by_likes]]
}