I am looking for a solution in CakePhp, to store and read temporary datas :
I read some XML from others websites in order to display some news in my website, but on each page load, it does a call to the other xml websites.
Is there a way (memcached like) to save temp. data in CakePhp in order to store data for 1 hour and read temp. data to display them in my webpages ; then 1 hour after update them (with cron) ?
Thanks.
CakePHP Caching seems what you'd want.
WHICH cache you use (Redis, Memcache...etc) would be up to you though. Set your cache to last an hour, and you're all set. (read more about cache on the link above).
If you're on CakePHP 2.5+, you can use the remember method described here.
public function newest() {
$model = $this;
return Cache::remember('newest_posts', function() use ($model){
// get your data from whatever source here, and return it
return $model->getMyData();
}, 'long');
}
Basically, this just checks to see if the cache key exists, and if not, runs some code in order to populate it again.
If you're below 2.5, you can do the same basic thing, but without the remember:
public function newest() {
$result = Cache::read('newest_posts', 'long');
if (!$result) {
// get your data from whatever source here, and write it
Cache::write('newest_posts', $this->getMyData(), 'long');
}
return $result;
}
If you don't have a cache engine installed or are aren't wanting to mess w/ your own server, there are companies that you can use for cache, and you can just set your cache settings to connect to them. ObjectRocket (Redis) is the one I know offhand, but I'm sure there are plenty.
One of many awesome things about CakePHP, is that in this case, your code doesn't change regardless of Cache type/location/configuration you choose.
Related
I am trying to create a plugin that will take the value of a listbox TV and set the document's createdby field to match that TV's setting onDocFormSave. The TV populates itself automatically with all active users and output's their ID.
I have the following code for the plugin, but when I try to save any resource it simply hangs and never saves. setCreatedBy is the name of the listbox TV:
switch ($modx->event->name) {
case 'onDocFormSave':
$created_by = $resource->getTVValue('setCreatedBy')
if ($resource->get('createdby') != $created_by) {
$modx->resource->set('createdby', $created_by));
}
break;
}
Untested.
It looks like setting also has to be done on the resource, not via the Modx-class.
$resource->set('createdby', $created_by); // You also have a ) too much in your code.
Inspected the docs.
If you omit the $resource->set... and run the plugin, will it pass? I'm wondering if you might be causing a loop, i.e $resource->set triggers another onDocFormSave. Do you have access to the server error.log? It probably contains whatever is crashing.
Those on the Modx forums were able to give me a leg up.
switch ($modx->event->name) {
case 'OnDocFormSave':
$created_by = $resource->getTVValue('setCreatedBy');
if (!empty($created_by) && $resource->get('createdby') != $created_by) {
$resource->set('createdby', $created_by);
$resource->save();
}
break;}
For reference, the way I handled gathering the names and user id's of Modx users and placing them in a selectbox TV was to use the Peoples snippet in an #EVAL binding:
#EVAL return $modx->runSnippet('Peoples',array('tpl'=>'peoplesTpl','outputSeparator'=>'||','active'=>'1'));
This is a petty dirty and slow way of doing things, but a request to have this be a standard field on Modx resources has been submitted to GitHub
I'm using Live Reporting Google APIs to retrieve active users and display the data inside a mobile application. On my application I'd like to make a HTTP request to a PHP script on my server which is supposed to return the result.
However I read on Google docs that it's better not to request data using APIs more often than 30 seconds.
I prefer not to use a heavy way such as a cron job that stores the value inside my database. So I'd like to know if there's a way to cache the content of my PHP scrpit na dmake it perform an API request only when the cache expires.
Is there any similar method to do that?
Another way could be implementing a very simple cache by yourself.
$googleApiRequestUrlWithParameter; //This is the full url of you request
$googleApiResponse = NULL; //This is the response by the API
//checking if the response is present in our cache
$cacheResponse = $datacache[$googleApiRequestUrlWithParameter];
if(isset($cacheResponse)) {
//check $cacheResponse[0] for find out the age of the cached data (30s or whatever you like
if(mktime() - $cacheResponse[0] < 30) {
//if the timing is good
$googleApiResponse = $cacheResponse[1];
} else {
//otherwise remove it from your "cache"
unset($datacache[$googleApiRequestUrlWithParameter]);
}
}
//if you do no have the response
if(!isset($googleApiResponse)) {
//make the call to google api and put the response in $googleApiResponse then
$datacache[] = array($googleApiRequestUrlWithParameter => array(mktime(), $googleApiResponse)
}
If you data are related to the user session, you could store $datacahe into $_SESSION
http://www.php.net/manual/it/reserved.variables.session.php
ortherwise define $datacache = array(); as a global variable.
There is a lot of way of caching things in PHP, the simple/historic way to manage cache in PHP is with APC http://www.php.net/manual/book.apc.php
Maybe I do not understard correctly your question.
How can i cache a particular part of the web page, I know how CI caching mechanism works also i am aware of Partial Caching.
Assume that we have a page with some dynamic data associated with. If i used caching then i cannot get the actual data on page refresh.
How can i override this problem ?
I have one idea in my mind, While inserting the data just keep another field, lets say MD5_CONTENTS which will store the MD5 hash of the contents ( Normally form fields ). And next time on update i can compare the MD5 strings to determine changes. If changes are found then delete the cache file.
I dont know this is gonna work or not, But its littlebit hard for my current implementation.
What is the best method to achieve Partial Caching ?
Thanks
Would the caching driver do the trick?
http://ellislab.com/codeigniter/user-guide/libraries/caching.html
$this->load->driver('cache', array('adapter' => 'apc', 'backup' => 'file'));
if ( ! $foo = $this->cache->get('foo'))
{
echo 'Saving to the cache!<br />';
$foo = 'foobarbaz!';
// Save into the cache for 5 minutes
$this->cache->save('foo', $foo, 300);
}
echo $foo;
Ok here is the link to the cache library he wrote: https://github.com/philsturgeon/codeigniter-cache
Anyway, his documentation is absolutely.. vague and not helpful at all. I know it's self explanatory.. to a point.
$this->cache->model('blog_m', 'getPosts', array($category_id, 'live'), 120); // keep for 2 minutes
What is the 3rd parameter?
And is that what creates the cache or this what creates a cache file:
$this->cache->write($data, 'cached-name');
And if that is, what exactly is $data suppose to be holding a value of? The overall query orrr...??
If anyone could give explanation on this on how you create a cache file.. Basically I want to cache the query that selects a bunch of news postings.. and everytime a new new post is created, to delete that cache and recache it so it shows the new news posting..
The documentation seems to be fairly clear. Anyways, I'll try to explain it in better terms:
// cached model call
$this->cache->model('blog_m', 'getPosts', array($category_id, 'live'), 120); // keep for 2 minutes
This calls the method getPosts on the model blog_m and caches the result for 120 seconds. If you make the same call again within the next 2min, it will return the cached results, otherwise it will fetch the data from the database and update the cache. It's good for methods on models that you will be calling very frequently.
If you want to manually add and get data from a cache, then you use:
// cached array or object
$this->cache->write($data, 'cached-name');
$data = $this->cache->get('cached-name');
$data will hold whatever you want to cache. If you want to cache the user's email, for example, here's how you would cache and fetch it
$email = 'foobar#example.com';
$this->cache->write($email, 'user-email');
// to fetch
$user_email = $this->cache->get('user-email');
i need to implement a simple project using PHP and MySql in which i need to push data to the user's UI when some one else is updating the database, and i need to periodically do this too, so when some one else accessing the same table and modify it, another person who uses the UI can see the updates, sorry if i'm being silly but up to now i'm only aware of saving data to a database and retrieving and showing it to the user(simplest form of data base connection). how can i achieve this in php, please some one help me on this matter, if the answer explains the things in detail it is good, because i'm very novice to this.thanks in advance.
rangana.
If the web page has no data to return, then get the page to wait for a period while polling the database. You must use the sleep statement to avoid maxing out your server.
Warning: Some servers wont let the user open another page while one is in progress, which may cause you problems in some situations. So either dont hold the page open for too long, or maybe try to get the ajax page to use a different session.
// do this when you have put new data in to database
setappdata("lastupdate",microtime(true));
// use this loop to poll for new data
$loop = 0;
$lastupdate=$_SESSION["lastupdate"];
while ($lastupdate==$last=getappdata("lastupdate") and $loop<10) {
$loop++;
usleep(500000); //0.5sec
}
// use a table called appdata to store application data
function getappdata($var) {
$query = "SELECT data FROM appdata WHERE var='$var'";
$res1=mysql_query($query);
if (mysql_numrows($res1)<1) return false;
return mysql_result($res1,0,"data");
}
function setappdata($var,$data) {
$query = "SELECT data FROM appdata WHERE var='$var'";
$res1=mysql_query($query);
if (mysql_numrows($res1)>0) $query = "UPDATE appdata SET data='$data' WHERE var='$var'";
else $query = "INSERT INTO appdata SET var='$var',data='$data'";
return mysql_query($query);
}
These topics may get you started:
http://en.wikipedia.org/wiki/Push_technology
http://en.wikipedia.org/wiki/Reverse_Ajax