Zend framework caching pagination results for different queries - php

Using Zend Paginator and the paginator cache works fine, but the same cached pages are returned for everything. Ie. I first look at a list of articles, when i go to view the categories the articles list is returned. How can I tell the paginator which result set i am looking for?
Also, how can I clear the paginated results without re-querying the paginator. Ie. I am updated a news article therefore the pagination needs to be cleared.
Thanks

Zend_Paginator uses two methods to define cache ID: _getCacheId and _getCacheInternalId. Second function is calculating cache ID based on two parameters: the number of items per page and special hash of the adapter object. The first function (_getCacheId) is calculating cache ID using result from _getCacheInternalId and current page.
So, if you are using two different paginator objects with 3 same internal parameters: adapter, current page number and the number of items per page, then your cache ID will be the same for these two objects.
So the only way I see is to define you own paginator class inherited from Zend_Paginator and to re-define one of these two internal functions to add a salt to cache ID.
Something like this:
class My_Paginator extends Zend_Paginator {
protected $_cacheSalt = '';
public static function factory($data, $adapter = self::INTERNAL_ADAPTER, array $prefixPaths = null) {
$paginator = parent::factory($data, $adapter, $prefixPaths);
return new self($paginator->getAdapter());
}
public function setCacheSalt($salt) {
$this->_cacheSalt = $salt;
return $this;
}
public function getCacheSalt() {
return $this->_cacheSalt;
}
protected function _getCacheId($page = null) {
$cacheSalt = $this->getCacheSalt();
if ($cacheSalt != '') {
$cacheSalt = '_' . $cacheSalt;
}
return parent::_getCacheId($page) . $cacheSalt;
}
}
$articlesPaginator = My_Paginator::factory($articlesSelect, 'DbSelect');
$articlesPaginator->setCacheSalt('articles');
$categoriesSelect = My_Paginator::factory($categoriesSelect, 'DbSelect');
$articlesPaginator->setCacheSalt('categories');

Related

Eloquent Relationship with a conditional scope

I'm working on a Fantasy sports app. The models I am working with are FantasyPlayer, PlayerGame, TeamGame
FantasyPlayer can have many PlayerGame and can have many TeamGame
public function PlayerGame()
{
return $this->hasMany('App\Models\PlayerGame','player_id','player_id');
}
public function TeamGame()
{
return $this->hasMany('App\Models\FantasyData\TeamGame','team','fantasy_player_key');
}
When I load the data I use eager loading currently:
FantasyPlayer::with(['PlayerGame', 'TeamGame'])->take(1)->get();
It is becoming tedious to load both relationships and then which are loaded. Ideally, I want to have the model handle this logic for. So I would be able to do something like this:
FantasyPlayer::with(['FantasyGame'])->take(1)->get();
Then my FantasyGame scope would contain either the PlayerGame or the TeamGame record I need based on an a FantasyPlayer value for the position. Something like this is what I want... but it doesn't work for me:
public function scopeFantasyGame($query)
{
if($this->position == "DEF"){
return $this->TeamGame();
}
else{
return $this->PlayerGame();
}
}
Does anyone know way I could use eager loading and have the FantasyGame return the correct relationship based on a FantasyPlayer position attribute?:
FantasyPlayer::with(['FantasyGame'])->take(1)->get();
#1
You can't eager load relationships conditionally based on the result elements, this because the eager loading happens before you retrieve the records, that's why this won't work:
# FantasyPlayer.php
public function scopeFantasyGame($query)
{
if($this->position == "DEF") // <--- Laravel doens't retrieve the records yet,
{ // so this won't work
//
}
else
{
//
}
}
#2
Local Query scopes are used to constraint queries, in your case you want to load relationships with this scope, not its general purpose but sure you could do it:
# FantasyPlayer.php
public function scopeFantasyGame($query)
{
return $query->with(['PlayerGame', 'TeamGame']);
}
Then use it like this:
# YourController.php
public function myFunction($query)
{
$fantasyPlayers = FantasyPlayer::fantasyGame()->get();
}
#3
But then, if you want to always eager load the relationships, why use a query scope and not just tell laravel to load your desired relationships by default? You could do specify it in your model (check the Eager Loading By Default of this section of the docs):
# FantasyPlayer.php
protected $with = ['PlayerGame', 'TeamGame'];
Update
If you want to retrieve elements that always have a given relationship, you have two paths. For the first one, you could use a query scope to only load those elements:
# FantasyPlayer.php
public function scopeHasFantasyGame($query)
{
return $query
->has('PlayerGame')
->has('TeamGame');
}
Then:
# YourController.php
public function myFunction($query)
{
$fantasyPlayers = FantasyPlayer::hasFantasyGame()->get();
}
The second option would be to retrieve the elements, then filter the collection based on the existence of the relationship (using the Map() function):
# YourController.php
public function myFunction($query)
{
$fantasyPlayers = FantasyPlayer::all()
->map(function ($fantasyPlayer) {
return $fantasyPlayer->PlayerGame()->exists()
&& $fantasyPlayer->TeamGame()->exists();
});
}

Implementing a S.O.L.I.D Domain Object Model in the following project

I have the following example in which I tend to use a couple of classes, to create a simple web app.
The file hierarchy seems like this.
> cupid
- libs
- request
- router
- database
- view
- bootstrap.php
- index.php
The index.php just calls the bootstrap.php which in turn contains something like this:
// bootstrap.php
namespace cupid
use request, router, database, view;
spl_autoload_register(function($class){ /* autoload */ });
$request = new view;
$response = new response;
$router = new router;
$database = new database;
$router->get('/blog/{id}', function($id) use ($database, $view) {
$article = $database->select("SELECT blog, content FROM foo WHERE id = ?",[$id]);
$view->layout('blogPage', ['article'=>$article]);
});
As you can probably tell, my problem is this line:
$article = $database->select("SELECT blog, content FROM foo WHERE id = ?", [$id]);
Which I don't want to use, and instead try a " Domain Object Model " approach.
Now, given that I will add another folder called domain, with blog.php
> cupid
- domain
- Blog.php
- libs
...
And fill blog.php with properties mapping table rows, and getter and setters ..
namespace App\Domain;
class Blog {
private $id, $title, $content, $author;
public function getTitle(){
return $this->title;
}
public function setTitle($title){
$this->title = $title;
}
...
}
My question is: Assuming my understanding of DOM is so far correct, and that I have a CRUD/ORM class, or a PDO wrapper to query the database;
"How can I tie together, i.e. the blog model with the PDO wrapper to fetch a blog inside my bootstrap file?"..
As far as a Domain Object you basically already have written one, your blog object. To qualify as a domain model all a class must to is to provide a representation along with any of the functionality of a concept within your problem space.
The more interesting problem here and the one you appear to be struggling with is how to persist a domain model. Keeping with the tenet of the single responsibility principle your Blog class should deal with being a blog post and doing the things that a blog post can do, not storing one. For that you would introduce the concept of a repository of blog posts that would deal with storing and retrieving objects of this type. Below is a simple implementation of how this can be done.
class BlogRepository {
public function __construct(\cupid\database $db){
$this->db = $db;
}
public function findById($id){
$blogData = $this->db->select("select * from blog where id = ?", [$id]);
if ($blogData){
return $this->createBlogFromArray($blogData);
}
return null;
}
public function findAllByTag($tag){...}
public function save(Blog $blog) {...}
private function createBlogFromArray(array $array){
$blog = new Blog();
$blog->setId($blogData["id"]);
$blog->setTitle($blogData["title"]);
$blog->setContent($blogData["content"]);
$blog->setAuthor($blogData["author"]);
return $blog;
}
}
Then your controller should look something like this.
$router->get('/blog/{id}', function($id) use ($blogRepository, $view) {
$article = $blogRepository->findById($id);
if ($article) {
$view->layout('blogPage', ['article'=>$article]);
} else {
$view->setError("404");
}
});
To truly be SOLID the above class should be a database specific implementation of a BlogRepository interface to adhere to IoC. A factory should also probably be supplied to BlogRepository to actually create the blog objects from data retrieved from the store.
In my opinion one of the great benefits of doing this is you have a single place where you can implement and maintain all of your blog related interactions with the database.
Other Advantages to this method
Implementing caching for your domain objects would be trivial
Switching to a different data source (from flat files, blogger api, Document Database Server,PostgresSQL etc.) could be done easily.
You can alternatively use a type aware ORM for a more general solution to this same problem. Basically this Repository class is nothing more than a ORM for a single class.
The important thing here is that you are not talking directly to the database and leaving sql scattered throughout your code. This creates a maintenance nightmare and couples your code to the schema of your database.
Personally I always tend to stick the database operations in a database class which does all the heavy lifting of initialising the class, opening the connection etc. It also has generic query-wrappers to which I pass the SQL-statements which contains the normal placeholders for the bound variables, plus an array of the variables to be bound (or the variable number of parameters approach if thats suits you better). If you want to bind each param individually and not use the $stmt->execute(array()); You just pass in the types with the value in a data structure of your choosing, multi dim array, dictionary, JSON, whatever suits your needs and you find easy to work with.
The model class it self (Blog in your case) then subclasses the Database. Then you have a few choices to make. Do you want to use the constructor to create only new objects? Do you want it to only load based on IDs? Or a mix of both? Something like:
function __construct(id = null, title = null, ingress = null, body = null) {
if(id){
$row = $this->getRow("SELECT * FROM blog WHERE id = :id",id); // Get a single row from the result
$this->title = $row->title;
$this->ingress = $row->ingress;
$this->body = $row->body;
... etc
} else if(!empty(title,ingress,body)){
$this->title = title;
... etc
}
}
Maybe neither? You can skip the constructor and use the new(title, ingress, body), save() and a load(id) methods if thats your preference.
Of course, the query part can be generalised even further if you just configure some class members and let the Database-superclass do the query building based on what you send in or set as member-variables. For example:
class Database {
$columns = []; // Array for storing the column names, could also be a dictionary that also stores the values
$idcolumn = "id"; // Generic id column name typically used, can be overridden in subclass
...
// Function for loading the object in a generic way based on configured data
function load($id){
if(!$this->db) $this->connect(); // Make sure we are connected
$query = "SELECT "; // Init the query to base string
foreach($this->columns as $column){
if($query !== "SELECT ") $query .= ", "; // See if we need comma before column name
$query .= $column; // Add column name to query
}
$query .= " FROM " . $this->tablename . " WHERE " . $this->idcolumn . " = :" . $this->idcolumn . ";";
$arg = ["col"=>$this->idcolumn,"value"=>$id,"type"=>PDO::PARAM_INT];
$row = $this->getRow($query,[$arg]); // Do the query and get the row pass in the type of the variable along with the variable, in this case an integer based ID
foreach($row as $column => $value){
$this->$column = $value; // Assign the values from $row to $this
}
}
...
function getRow($query,$args){
$statement = $this->query($query,$args); // Use the main generic query to return the result as a PDOStatement
$result = $statement->fetch(); // Get the first row
return $result;
}
...
function query($query,$args){
...
$stmt = $this->db->prepare($query);
foreach($args as $arg){
$stmt->bindParam(":".$arg["col"],$arg["value"],$arg["type"]);
}
$stmt->execute();
return $stmt;
}
...
}
Now as you see the load($id), getrow($query,$args) and query($query,$args) is completely generic. ´getrow()´is just a wrapper on query() that gets the first row, you may want to have several different wrappers that to or interpret your statement result in different ways. You may also even want to add object specific wrappers to your models if they cannot be made generic. Now the model, in your case Blog could look like:
class Blog extends Database {
$title;
$ingress;
$body;
...
function __construct($id = null){
$this->columns = ["title","ingress","body","id",...];
$this->idcolumn = "articleid"; // override parent id name
...
if($id) $this->load($id);
}
...
}
Use it as so: $blog = new Blog(123); to load a specific blog, or $blog = new Blog(); $blog->title = "title"; ... $blog->save(); if you want a new.
"How can I tie together, i.e. the blog model with the PDO wrapper to fetch a blog inside my bootstrap file?"..
To tie the two together, you could use an object-relational mapper (ORM). ORM libraries are built just for glueing your PHP classes to database rows. There are a couple of ORM libraries for PHP around. Also, most ORMs have a built in database abstraction layer, which means that you can simply switch the database vendor without any hassle.
Considerations when using an ORM:
While introducing a ORM also introduces some bloat (and some learning), it may not be worthwhile investing the time for simply a single Blog object. Although, if your blog entries also have an author, one or multiple categories and/or associated files, an ORM may soon help you reading/writing the database. Judging from your posted code, an ORM will pay off when extending the application in the future.
Update: Example using Doctrine 2
You may have a look at the querying section of the official Doctrine documentation to see the different options you have for read access. Reconsider the example you gave:
// current implementation
$article = $database->select("SELECT blog, content FROM foo WHERE id = ?",[$id]);
// possible implementation using Doctrine
$article = $em->getRepository(Blog::class)->find($id);
However, ideally you define your own repository to separate your business logic from Doctrines API like the following example illustrates:
use Doctrine\ORM\EntityRepository;
interface BlogRepositoryInterface {
public function findById($id);
public function findByAuthor($author);
}
class BlogRepsitory implements BlogRepositoryInterface {
/** #var EntityRepository */
private $repo;
public function __construct(EntityRepository $repo) {
$this->repo = $repo;
}
public function findById($id) {
return $this->repo->find($id);
}
public function findByAuthor($author) {
return $this->repo->findBy(['author' => $author]);
}
}
I hope the example illustrates how easily you can separate your business domain models and logic from the underlying library and how powerful ORMs can come into play.

PHP OOP: Good practice for fetching from database with object constructors

I have two database tables Players and Units. Respectively I also have two classes in PHP that look pretty identically in the base.
class Player {
private $id;
private $name;
// a bunch of other properties
public function __construct($id){
// fetch info from database with $id and populate properties
}
}
 
class Unit {
private $id;
private $name;
// a bunch of other properties
public function __construct($id){
// fetch info from database with $id and populate properties
}
}
But one player can have multiple units, so I implemented the method loadUnits() in the Player class
public function loadUnits(){
$units = array();
foreach($db->prepare('SELECT id FROM units WHERE owner = ?')->execute([$this->id])->fetchAll() as $unit){
$units[] = new Unit($unit['id']);
}
return $units;
}
The problem is that constructing Unit X number of times will make X number of calls to the database and this is really something I don't like. I would like to ask what are the good practices and how is this done in reality? Thanks!
Instead of just selecting the id in loadUnits and then issuing another query for the properties per id, I recommend getting all unit properties with a single query and passing those properties to the constructor of Unit
//don't just get the id's, get the actual unit properties
public function loadUnits(){
$units = array();
foreach($db->prepare('SELECT <all properties> FROM units WHERE owner = ?')->execute([$this->id])->fetchAll() as $properties){
$units[] = new Unit($properties['id'],$properties);
}
return $units;
}
class Unit {
private $id;
private $name;
// a bunch of other properties
//make the unit properties an optional parameter and use it
//instead of querying the db if available
public function __construct($id,$properties=null){
if(is_null($properties)) {
// fetch info from database with $id and populate properties
}
else {
// populate via $properties
}
}
}
I have a similar problem in one of my projects. Calling Room->computeDoors() will run a query to find what Doors are attached to the Rooms, then for each of them it has to run a query to find out what the Door's properties are... and then it has to query each room to find out what the door is connected to!
Problem solved: Memcache. Store as much as you can in cache, that way the data's already there to be used no matter how many times you need it, even across pageloads/AJAX calls, or even across users! Just make sure to invalidate or update the cache when you update the object's state.
You can solve this bei either using an ORM like Doctrine or Eloquent.
In Doctrine you define the relations between your entities, it will automatically generate the SQL and tables, it will generate proxies containing findBy() methods, give notes about wrong relations or missing values.
Doctrine has implemented different fetching methods and caching for example persistence of entities and lazy loading. You define your model and Doctrine takes care of everything else the most stable and fastest way.
If you want to implement your own, you should cache the results locally in the instance.
private $units;
protected function loadUnits(){
$units = array();
foreach($db->prepare('SELECT id FROM units WHERE owner = ?')->execute([$this->id])->fetchAll() as $unit){
$units[] = new Unit($unit['id']);
}
$this->setUnits($units);
return $this;
}
public function setUnits($units) {
assert(is_array($units));
$this->units = $units;
return $this;
}
public function getUnits() {
// this if needs improvement to fit your needs
if (!is_array($this->units)) {
$this->loadUnits();
}
return $this->units;
}

Zend MVC: one call from controller to model or more calls for differents results?

i need differents results from a model but i don't understand if it is correct make a single call and leave to model all the work or make more calls and collect the result to pass to the view when tables aren't joined or when i need fetch one row from a table and differents rows from others.
First example (more calls, collect and send to view):
CONTROLLER
// call functions of model
$modelName = new Application_Model_DbTable_ModelName();
$rs1 = $modelName->getTest($var);
$rs2 = $modelName->getTest2($var2);
// collect data
$pippo = $rs1->pippo;
if ($rs2->pluto == 'test') {
$pluto = 'ok';
} else {
$pluto = 'ko';
}
// send to view
$this->view->pippo = $pippo;
$this->view->pluto = $pluto;
MODEL
public function getTest($var) {
...
select from db...
return $result;
...
}
public function getTest2($var) {
...
select from db...
return $result;
...
}
Second example (one call, model collect all data, return to controller and send to view):
CONTROLLER
// call one function of model
$modelName = new Application_Model_DbTable_ModelName();
$rs = $modelName->getTest($var);
MODEL
public function getTest($var) {
...
select from db...
if ($result > 0) {
call other function
call other function
collect data
return $result;
...
}
Thanks
There's no one correct answer to this question, but in general, you should endeavor to keep your business logic in one place. Think of it as, "thin controller, thick model." I.e., keep the controllers as small and simple as possible and put all the business logic in the models.
There seems to be a few questions here:
But if i don't need to interact with db and i need only a simply
function is better put that function in model? For example:
CONTROLLER:
public function printAction() {
$data = $this->getRequest()->getPost();
$label = "blablabla";
$this->view->label = $label;
}
first, in the context of Zend Framework this particular example doesn't make much sense. The whole point of the controller is to populate the view template. However, I do get the idea. I would point you to Action Helpers and View helpers as a means to address your concerns. You can always add a utility class to your library for those pieces of code that don't seem to fit anywhere else.
Action Helpers typically are employed to encapsulate controller code that may be repetitive or reusable. They can be as simple or as complex as required, here is a simple example:
class Controller_Action_Helper_Login extends Zend_Controller_Action_Helper_Abstract
{
/**
* #return \Application_Form_Login
*/
public function direct()
{
$form = new Application_Form_Login();
$form->setAction('/index/login');
return $form;
}
}
//add the helper path to the stack in the application.ini
resources.frontController.actionhelperpaths.Controller_Action_Helper = APPLICATION_PATH "/../library/Controller/Action/Helper"
//the helper is called in the controller
$this->_helper->login();
a View helper does the same thing for the view templates:
class Zend_View_Helper_PadId extends Zend_View_Helper_Abstract
{
/**
* add leading zeros to value
* #param type $id
* #return string
*/
public function padId($id)
{
return str_pad($id, 5, 0, STR_PAD_LEFT);
}
}
//in this example the helper path is added to the stack from the boostrap.php
protected function _initView()
{
//Initialize view
$view = new Zend_View();
//add custom view helper path
$view->addHelperPath('/../library/View/Helper');
//truncated for brevity
$viewRenderer = Zend_Controller_Action_HelperBroker::getStaticHelper(
'ViewRenderer');
$viewRenderer->setView($view);
//Return it, so that it can be stored by the bootstrap
return $view;
}
//and to use the helper in the view template
//any.phtml
<?php echo $this->padId($this->id) ?>
i need differents results from a model but i don't understand if it is
correct make a single call and leave to model all the work or make
more calls and collect the result to pass to the view when tables
aren't joined or when i need fetch one row from a table and differents
rows from others.
This question is more about structure then about correctness.
You can interact with your database table models in Action and View helpers for simple/repetitive queries if you need to, however most developers might frown on this approach as being difficult to maintain or just ugly.
Many people seem to favor Doctrine or Propel to help them manage their database needs.
At this point I like to roll my own and currently favor domain models and data mappers, not an end all be all pattern, but seems to be appropriate to your question.
This is not a simple suggestion to implement for the first time, however i found two articles helpful to get started:
http://phpmaster.com/building-a-domain-model/
http://phpmaster.com/integrating-the-data-mappers/
and if you really want to get into it try:
http://survivethedeepend.com/
I hope this answers at least a part of your questions.

PHP: Get id from database, send to other function to get content?

I hope the title was descriptive enough, i wasn't sure how to name it.
Let's say i have the following code:
Class Movie_model {
public method getMoviesByDate($date) {
// Connects to db
// Gets movie IDs from a specific date
// Loop through movie IDs
// On each ID, call getMovieById() and store the result in an array
// When all IDs has looped, return array with movies returned from getMovieById().
}
public function getMovieById($id) {
// Get movie by specified ID
// Also get movie genres from another method
// Oh, and it gets movie from another method as well.
}
}
I always want to get the same result when getting a movie (I always want the result from getMovieById().
I hope you get my point. I will have many other functions like getMoviesByDate(), i will also have getMoviesByGenre() for example, and i want that to return the same movie info as getMovieById() as well.
It it "ok" to do it this way? I know this puts more load on the server and increases load time, but is there any other, better way that i don't know of?
EDIT: I clarified the code in getMoviesByDate() a bit. Also, getMovieByDate() is just an example. As i said, i will be calling methods like getMoviesByGenre() also.
EDIT: I'm currently running 48 database queries on the frontpage of my project, and the frontpage is still far from finished, so that number would at least triple when i'm done. Almost all queries take around 0.0002, but as the database keeps growing that number will rise dramatically i'm guessing. I need to change something.
I don't think it's good to work like this in this particular case. The function getMoviesByDate would return an amount of "n" movies (or movie ids) from a single query. For each id in this query you would have a separate query to get the movie by the specified ID.
This would mean if the first function would return 200 movies, you would run the getMovieById() function (and the query inside it) 200 times. A better practice (IMO) would be to just get all the info you require in the getMoviesByDate() function and return it as a collection.
It doesn't seem very logical to have getMoviesByDate() and getMoviesById() methods on a Movie class.
An alternative would be to have some sort of MovieManager class that does all of the retrieving, and returns Movie objects.
class MovieManager {
public function getMoviesByDate($date) {
// get movies by date, build an array of Movie objects and return
}
public function getMoviesByGenre($genre) {
// get movies by genre, build an array of Movie objects and return
}
public function getMovieById($id) {
// get movie by id, return Movie object
}
}
Your Movie class would just have properties and methods specific to a single movie:
class Movie {
public id;
public name;
public releaseDate;
}
It's OK to have separate methods for getting by date, genre etc etc, but you must ensure that you are not calling for the same records multiple times - in that case you will want a single query that could join the various tables you need.
Edit - after you have clarified your question:
The idea of getting movie IDs by date, then running them all through getMovieById() is bad! The movie data should be pulled when getting by date, so you don't have to hit the database again.
You can modified your getMovieById function. You can pass date as a parameter, the function should return the movies by their id and filtered by date.
To keep track which records you've already loaded into RAM previously you can use a base class for your models which saves the id's of the records already loaded and a reference to object the model object in the RAM.
class ModelBase {
/* contains the id of the current record, null if new record */
protected $id;
// keep track of records already loaded
static $loaded_records = Array();
public function __construct(Array $attr_values) {
// assign $attr_values to this classes attributes
// save this instance in class variable to reuse this object
if($attr_values['id'] != null) {
self::$loaded_records[get_called_class()][$attr_values['id']] = $this;
}
}
public static function getConcurrentInstance(Array $attr_values) {
$called_class = get_called_class();
if(isset(self::$loaded_records[$called_class][$attr_values['id']])) {
// this record was already loaded into RAM
$record = self::$loaded_records[$called_class][$attr_values['id']];
// you may need to update certain fields of $record
// from the data in $attr_values, because the data in the RAM may
// be old data.
} else {
// create the model with the given values
$record = new $called_class($attr_values);
}
return $record;
}
// provides basic methods to update records in ram to database etc.
public function save() {
// create query to save this record to database ...
}
}
Your movie model could look something like this.
Class MovieModel extends ModelBase {
// additional attributes
protected $title;
protected $date;
// more attributes ...
public static function getMoviesByDate($date) {
// fetches records from database
// calls getConcurrentInstance() to return an instance of MovieModel() for every record
}
public static function getMovieById($id) {
// fetches record from database
// calls getConcurrentInstance() to return an instance of MovieModel()
}
}
Other things you could do do decrease the load on the DB:
Only connect once to the database per request. There are also possibilities to share a connection to a database between multiple requests.
Index thefields in your database which get searched often.
only fetch the records you need
Prevent to load the same record twice (if it didn't change)

Categories