然后我们就在项目文件里找到同名文件开始困难晦涩地学习
<?phpdefined ( 'BASEPATH' ) or exit ( 'No direct script access allowed' );class Doing extends CI_Controller { function __construct() { parent::__construct(); //调用doing_model模型 $this->load->model("doing_model"); $this->load->model("topic_model"); } function index() { $navtitle = "问答动态"; $type = 'atentto'; //获取第三分段的参数，无参数便是默认界面 $recivetype = $this->uri->segment ( 3 ); if ($recivetype) { $type = $recivetype; } if (!$this->user['uid']) { $type = 'all'; } $navtitletable = array( 'all' => '问答动态', 'my' => '我的动态', 'atentto' => '关注的动态' //default ); $navtitle = $navtitletable[$type]; //分页设置 $page = max(1, intval($this->uri->segment ( 4 ))); $pagesize = $this->setting['list_default']; $startindex = ($page - 1) $pagesize; $doinglist = $this->doing_model->list_by_type($type, $this->user['uid'], $startindex, $pagesize); $rownum = $this->doing_model->rownum_by_type($type, $this->user['uid']); $departstr = page($rownum, $pagesize, $page, "doing/default/$type"); if ($type == 'atentto') { $recommendsize = $rownum ? 3 : 6; $recommandusers = $this->doing_model->recommend_user($recommendsize); } $userarticle=$this->topic_model->get_user_articles(0,5); include template('doing'); }}?>
代码不是很长，但是这背后引申出好几个文件，还是很须要一番韶光来学习的。先一段一段地剖析语句吧。从下面这段代码里我们可以知道，这个页面的架构调用了model里面的“doing-model”业务模型
function __construct() { parent::__construct(); //调用doing_model模型 $this->load->model("doing_model"); $this->load->model("topic_model");}
然后接着看index函数里的语句
$navtitle = "问答动态";$type = 'atentto';//获取第三分段的参数，无参数便是默认界面$recivetype = $this->uri->segment ( 3 );if ($recivetype) { $type = $recivetype;}if (!$this->user['uid']) { $type = 'all';}$navtitletable = array( 'all' => '问答动态', 'my' => '我的动态', 'atentto' => '关注的动态' //default);$navtitle = $navtitletable[$type];
这一段紧张的浸染是确定type的属性，由上面三张网页图可知，不同type情形下呈现的动态的数量是不同的，type关系到下面动态数据的筛选。在确定type属性这里我们用到的核心语句是
$this->uri->segment ( );
这行语句来自CI框架URI类中的一个函数
紧张目的便是从URI中得到我们想要的一个字段，从index后面的“/”从1开始计数，以是$this->uri->segment ( 3 )便是index后面的第三段
像default界面没有3段，以是返回null值，type还是一开始默认设置的“atentto”，然后便是页面分页的设置，这一部分是所有项目的公共部分，与我们本日谈论的问题无关，以是我们连续往下看
//type对应动态类型$doinglist = $this->doing_model->list_by_type($type, $this->user['uid'], $startindex, $pagesize);$rownum = $this->doing_model->rownum_by_type($type, $this->user['uid']);
我们可以创造，这里有两个变量分别调用了doing_model里面的两个函数，以是我们就在doing_model文件里搜索函数名，就能分别得到两个函数，list_by_type函数很长，在这里只截取一部分，不妨碍理解
function list_by_type($searchtype = 'all', $uid = 0, $start = 0, $limit = 20) { $doinglist = array (); $sql = ""; $uid = intval ( $uid ); switch ($searchtype) { case 'all' : $sql .= "select from " . $this->db->dbprefix . "doing where action in(1,2,3,6,9,11)"; break; case 'my' : $sql .= "select from " . $this->db->dbprefix . "doing where authorid=$uid "; break; case 'atentto' : $sql .= "select d. from " . $this->db->dbprefix . "doing as d," . $this->db->dbprefix . "user_attention as u where d.authorid=u.uid and u.followerid=$uid and action in(1,2,3,6,9,11)"; break; }
可以创造，不同的type使得我们在数据库里检索数据的条件也会不同，因而得到的结果也不同，以是涌现了上图三种情形的动态页面。当然，我们也可以在mysql里面找到同名数据表，对应上面代码的查询条件，加深我们对付数据库里各个数据表含义、数据字段的理解。
//list_by_type函数续$sql .= " ORDER BY createtime DESC LIMIT $start,$limit";$query = $this->db->query ( $sql );foreach ( $query->result_array () as $doing ) { $doing ['doing_time'] = tdate ( $doing ['createtime'] );//显示几天前的操作 $doing ['user'] = $this->get_by_uid ( $doing ['authorid'] ); $doing ['avatar'] = get_avatar_dir ( $doing ['authorid'] ); $doing ['actiondesc'] = $this->actiontable [$doing ['action']]; $doing ['followerlist'] = $this->get_follower ( $doing ['questionid'] ); if ($doing ['refer_authorid']) { $doing ['refer_avatar'] = get_avatar_dir ( $doing ['refer_authorid'] ); } switch ($doing ['action']) { case '1' : // 提出了问题 $doing ['question'] = $this->getquestionbyqid ( $doing ['questionid'] ); $doing ['category'] = $this->get_cat_bycid ( $doing ['question'] ['cid'] ); $doing ['categoryname'] = $doing ['category'] ['name']; $doing ['cid'] = $doing ['category'] ['id']; $doing ['title'] = $doing ['question'] ['title']; $doing ['hidden'] = $doing ['question'] ['hidden']; $doing ['views'] = $doing ['question'] ['views']; $doing ['answers'] = $doing ['question'] ['answers']; $doing ['attentions'] = $doing ['question'] ['attentions']; $doing ['content'] = $doing ['question'] ['title']; $doing ['image'] = getfirstimg ( $doing ['question'] ['description'] ); $doing ['description'] = cutstr ( checkwordsglobal ( strip_tags ( $doing ['question'] ['description'] ) ), 240, '...' ); $doing ['url'] = urlmap ( 'question/view/' . $doing ['questionid'], 2 ); break; case '2' : / other code /}
利用CI框架的$this->db->query ( $sql )语句，访问我们前面查询好的数据集的数据，再进行遍历，通过doing-model模型设定的多个其他的函数，提取出数据库里的我们须要的数据及数据格式，然后根据各条数据的“action”对应的值，匹配动态不同的操作，末了输出结果，达到我们书写动态信息的目的。
list_by_type函数查找动态对应的用户的数据，rownum_by_type查找的是动态对应的问题的数据
//末了的部分//页面封装$departstr = page($rownum, $pagesize, $page, "doing/default/$type");if ($type == 'atentto') { $recommendsize = $rownum ? 3 : 6; $recommandusers = $this->doing_model->recommend_user($recommendsize);}//侧边栏的实现$userarticle=$this->topic_model->get_user_articles(0,5);//template为抽象模板，用于通过filename调用，大概是实现静态网页的模板include template('doing');
以上便是笔者艰涩的学习过程，希望笔者这些浅近的理解能对你有所帮助。如有缺点理解，也希望各位读者能悉心指出，感激。
