How i can echo php code to codeigniter view - php

Question

I want to filter data when user select click on the button all data is filtered correctly but tag not work properly.It will show two size but i will need one.
Here is pic of error:
And here is my model:
$result=NULL;
$this->db->select('*');
$this->db->from('sales');
$query = $this->db->get();
if($query->num_rows()>0)
{
foreach($query->result() as $all_prod)
{
$prod_size=NULL;
$make_option=NULL;
$flag=false;
$i=0;
$prod_size=$all_prod->sizes;
if (strpos($prod_size, ',') !== false)
{
$flag=true;
}
else
{
$flag=false;
}
$result.='<div class="col-lg-4 men-one">
<img src='.base_url($all_prod->img).' class="img-responsive">
<div class="row">
<p class="col-lg-10" style="margin-top:5px;">'.($all_prod->description).'
</p>
<span class="btn btn-light glyphicon glyphicon-heart col-lg-1"style="color:#C9302C"></span>
</div>
<div class="row">
<p class="col-lg-3 text-center">Rs:'.($all_prod->sale_price).'
</p>
<p class="col-lg-3 text-center"><strike>'. ($all_prod->orignal_price).'</strike>
</p>
<?php
if('.$flag.'=='.false.')
{
?>
<form class="col-lg-5">
<select class="size_color">
<option>Size</option>
<option>'.$prod_size.'</option>
</select>
</form>
<?php
}
else
{
if('.$flag.'=='.true.')
{
?>
<form class="col-lg-5">
<select class="size_color">
<option>Size</option>
<?php
while('.$prod_size.'['.$i.']!='.NULL.')
{
if('.$prod_size.'['.$i.']!='.",".')
{
'.$make_option.'='.$make_option.'
.'.$prod_size.'['.$i.'];
}
else
{
if('.$prod_size.'['.$i.']=='.",".')
{
?>
<option>'.$make_option.'</option>
<?php
'.$make_option.'='.NULL.';
}
}
'.$i.'='.$i.'+1;
if('.$prod_size.'['.$i.']=='.NULL.')
{
?>
<option>'.$make_option.'</option>
<?php
'.$make_option.'=NULL;
'.$flag.'='.false.';
}
}
?>
</select>
</form>
<?php
}
}
?>
</div>
<button class="btn btn-danger col-lg-12" onclick="add_to_cart(id='.$all_prod->id.')">ADD TO CART</button>
</div>';
}
echo $result;
}
else
{
return false;
}
Thanks In Advance help me i spend too much time tried all possible method that i know but i'm not successful.