Here is what I would do in JavaScript. Is there any way to do it in php?
I am working on a project that needs this functionality but cannot use JavaScript.
setInterval ( "checkHistory()", 1000 );
function checkHistory() {
if (oldHistLength != history.length) {
removegateway();
oldHistLength = history.length;
}
}
Sorry to say that it's not possible to do that using PHP. Your only option is to use JavaScript somewhere.
You can however achieve what I believe you're trying to do with another technique - PHP Sessions and Request URIs.
This involves storing the user's accessed URLs into a variable (or you could use MySQL) which can be referenced anywhere on the website within that current session.
Here's an (untested) example:
<?php
session_start();
// Retrieve/create the current list
if( isset($_SESSION['history']) ) {
$history = $_SESSION['history'];
} else {
$history = new array();
}
// Add the current URL to the history array
array_push($history, $_SERVER['REQUEST_URI']);
// Do anything else you want to here
// Store the array again
$_SESSION['history'] = $history;
?>
In your code, you can keep an array containing the values of $_SERVER['php_self'], serialize() it, and store it in a session variable. This may not be sufficient for what you are trying to do though. I'm not sure what removegateway() does, but is this code attempting to prevent the back button from being used?
If you prevent the pages from being cached, you might be able to compare the second to the last value in your array to the current page, and if they match, you detected a back button. This would only be possible if there's no way to go back to the previous page on the front end.
Preventing the back button is generally considered a Bad Thing, so it might be better to reconsider the way you are doing things and come up with a better solution.
Related
I am new to php and have just written a basic index.php that will display family tree information for an individual based on input id.
The index.php includes a file called "xml-people-list.php" which loads the information from the family tree and creates a sorted list of people.
My problem is that every time you click on a person to display their details, the included php is reloaded which causes the read from file and creation of sorted list to happen again.
Is there a way to only run this code once per session to avoid multiple loads?
I tried to look at session variables but wasn't sure if they would help or how to use them in this case or if there is another way?
Contents of "xml-people-list.php:
<?php require 'xml-load-person.php';
if (file_exists('people.xml'))
{
$people = simplexml_load_file('people.xml');
foreach ($people->person as $person)
{
$person_list[(string)$person['ID']] = strtoupper($person->FamilyName) . ", " . $person->GivenNames;
}
asort($person_list);
}
else
{
exit('Failed to open people.xml.');
}
?>
Thanks for any help!
Yes, you could use session variables. If you wanted to only parse the list once per visitor, and then "cache" the result into a session variable, you could do something like this (for a simple example):
if (!empty($_SESSION['person_list'])) {
// Here we fetch and decode the the ready list from a session variable, if it's defined:
$person_list = json_decode($_SESSION['person_list']);
}
// Otherwise we load it:
else {
require 'xml-load-person.php';
if (file_exists('people.xml'))
{
$people = simplexml_load_file('people.xml');
foreach ($people->person as $person)
{
$person_list[(string)$person['ID']] = strtoupper($person->FamilyName) . ", " . $person->GivenNames;
}
asort($person_list);
// Here we assign the ready list to a session variable (as a JSON string):
$person_list = json_encode($person_list);
$_SESSION['person_list'] = $person_list;
// Here we revert the JSON-encoded (originally SimpleXML) object into a stdClass object.
$person_list = json_decode($person_list);
}
else
{
exit('Failed to open people.xml.');
}
}
You will need to call session_start() in your file (either this one, or any other file including it, but importantly before any output is sent to the browser). Homework: Read up on sessions in PHP.
Update: Since SimpleXML objects can't be serialized, and since adding an object to $_SESSION causes serialization, I've updated the answer to json_encode/decode the object. Yes there's a bit of processing, but that'd be the case with the default serialization as well, and json_en/decode is fairly light-weight. Certainly heaps lighter than parsing XML on each page load!
Be aware that the returned object will be a stdClass object, not a SimpleXML object. I'm assuming it won't be a problem in your use case.
Maybe try require_once() function
1) First of all, try to see if your buttons are anchor tags then be sure that the href attribute is directing to # example: <a href="#">
2) try to use include_once instead of requiring
3) if you tried this and these couple solutions didn't work for you you can send the id of a person using the global $_GET variable
//this should be you URL http://localhost/projectname/index.php?person_id=1
// your href of each person should appoint to their URL
// <a href="index.php?person_id=1">
you can use this $_GET['person_id'] and store it into a variable so it will give you the id of person.
for security reasons we need to disable a php/mysql for a non-profit site as it has a lot of vulnerabilities. It's a small site so we want to just rebuild the site without database and bypass the vulnerability of an admin page.
The website just needs to stay alive and remain dormant. We do not need to keep updating the site in future so we're looking for a static-ish design.
Our current URL structure is such that it has query strings in the url which fetches values from the database.
e.g. artist.php?id=2
I'm looking for a easy and quick way change artist.php so instead of fetching values from a database it would just include data from a flat html file so.
artist.php?id=1 = fetch data from /artist/1.html
artist.php?id=2 = fetch data from /artist/2.html
artist.php?id=3 = fetch data from /artist/3.html
artist.php?id=4 = fetch data from /artist/4.html
artist.php?id=5 = fetch data from /artist/5.html
The reason for doing it this way is that we need to preserve the URL structure for SEO purposes. So I do not want to use the html files for the public.
What basic php code would I need to achieve this?
To do it exactly as you ask would be like this:
$id = intval($_GET['id']);
$page = file_get_contents("/artist/$id.html");
In case $id === 0 there was something else besides numbers in the query parameter. You could also have the artist information in an array:
// datafile.php
return array(
1 => "Artist 1 is this and that",
2 => "Artist 2..."
)
And then in your artist.php
$data = include('datafile.php');
if (array_key_exists($_GET['id'], $data)) {
$page = $data[$_GET['id']];
} else {
// 404
}
HTML isn't your best option, but its cousin is THE BEST for static data files.
Let me introduce you to XML! (documentation to PHP parser)
XML is similar to HTML as structure, but it's made to store data rather than webpages.
If instead your html pages are already completed and you just need to serve them, you can use the url rewriting from your webserver (if you're using Apache, see mod_rewrite)
At last, a pure PHP solution (which I don't recommend)
<?php
//protect from displaying unwanted webpages or other vulnerabilities:
//we NEVER trust user input, and we NEVER use it directly without checking it up.
$valid_ids = array(1,2,3,4,5 /*etc*/);
if(in_array($_REQUEST['id'])){
$id = $_REQUEST['id'];
} else {
echo "missing artist!"; die;
}
//read the html file
$html_page = file_get_contents("/artist/$id.html");
//display the html file
echo $html_page;
Sorry if I'm duplicating threads here, but I wasn't able to find an answer to this anywhere else on StackOverflow.
Basically what I'm trying to do is make a list in which variables entered in a form by a user can be kept. At the moment, I have the code which makes this possible, and functional, however the variables entered in the form only appear on the list after the user hits submit... As soon as I refresh the page or go to the page from somewhere else, the variables disappear. Is there any way I can stop this from happening?
Edit: here are the codes:
//Page 1
<?php
session_start();
$entries = array(
0 => $_POST['signup_username'],
1 => $_POST['signup_email'],
2 => $_POST['signup_city']);
$entries_unique = array_unique($entries);
$entries_unique_values = array_values($entries_unique);
echo "<a href='Page 2'>Link</a>";
$_SESSION['entries_unique_values'] = $entries_unique_values;
?>
//Page2
<?php
session_start();
$entries_unique_values = $_SESSION['entries_unique_values'];
foreach($entries_unique_values as $key => $value) {
$ValueReplace = $value;
echo "<br /><a href='http://example.com/members/?s=$ValueReplace'>" . $value . "</a><br/>";
}
?>
Your question is really quite vague. the answer depends on how much data you have to store, and fopr how long you need it to exsist.
By variable I assume you mean data the user has entered and that you want to put into a variable.
I also presume that the list of variables is created by php when the form is submitted.
Php will only create the variable list when the form is submitted as php is done entirely on the server, therefore you will not have or see the variables until the form is submitted.
if you wanted to be able to see the list as it is being created you could use javascript then once you have you php variables the javascript list isn't necesary.
each time you request a php page wheather it is the same one or not the server generates a totally new page, meaning all unhardcoded variables from previous pages will be lost unless you continually post the variables around the pages the server will have no memory of them.
You have a few viable options.
) keep passing the user created variables in POST or GET requests so each page has the necesary info to work with. Depending on the situation it might or might not be a good idea. If the data only needs to exsits for one or two pages then it is ok, but bad if you need the data to be accessable from any page on your web.
2.) start a session and store the variables in a session. Good if the data only needs to be around while the user is connected to the site. but will be lost if user close window or after a time.
3.) place a cookie. not a good idea but ok for simple data.
4.) create a mysql database and drop the variable info in there. great for permanent data. this is how i always complex user data.
just a few ideas for you to look into as it is difficult to see what you really mean. good luck.
use PHP session or store variable values in Cookies via JS or using PHP. It would be nice if you show your working codes :)
Your idea is fine, however you just need to add a little condition to your Page 1 that only set your SESSION values when POST is made, that way it will keep the values even if you refresh. Otherwise when you visit the page without a POST those values will be overwritten by blank values, which is what you are seeing now. You can modify it like
<?php
session_start();
if(isset($_POST["signup_username"]))
{
$entries = array(
0 => $_POST['signup_username'],
1 => $_POST['signup_email'],
2 => $_POST['signup_city']);
$entries_unique = array_unique($entries);
$entries_unique_values = array_values($entries_unique);
$_SESSION['entries_unique_values'] = $entries_unique_values;
}
echo "<a href='http://localhost/Calculator/form2.1.php'>Link</a>";
?>
You could use JavaScript and HTML5 local storage.
One solution to automatically building navigation for a site is by scanning a folder for documents like this:
foreach(glob('pages/*.pg.php') as $_SITE_NAV_filePath):
$_SITE_NAV_filePath = explode('.pg',pathinfo($_SITE_NAV_filePath,PATHINFO_FILENAME));
$_SITE_NAV_fileName = $_SITE_NAV_filePath[0];
$_SITE_NAV_qv = preg_replace('/([A-Z])/','-$1',$_SITE_NAV_fileName); $_SITE_NAV_qv = trim($_SITE_NAV_qv,'-');
$_SITE_NAV_name = preg_replace('/([A-Z])/',' $1',$_SITE_NAV_fileName);
?>
<li><?=$_SITE_NAV_name?></li>
<?php
endforeach;
This code will turn "AnAwesomePage.pg.php" into a menu item like this :
<li>An Awesome Page</li>
This might be bad practice (?).
Anyway; I don't use this method very often since most of the time the sites have a database, and with that comes better solutions...
But my question is this:
Is there a way to prefix the filename with a integer followed by and underscore (3_AnAwesomePage.pg.php), for sorting order purposes, and pass it somehow to the destination page outside of the querystring and without any async javascript?
I could just explode the filename once again on "_" to get the sort order and store it somewhere, somehow?
This is the code for handeling the page query request:
$_SITE_PAGE['qv'] = $_GET['page'];
if (empty($_SITE_PAGE['qv'])){ $_SITE_PAGE['qv'] = explode('-','Home'); }
else { $_SITE_PAGE['qv'] = explode('-',$_GET['page']); }
$_SITE_PAGE['file'] = 'pages/'.implode($_SITE_PAGE['qv']).'.pg.php';
This code turns "An-Awesome-Page" back into "AnAwesomePage.pg.php" so it's possible to include it with php.
But with a prefix, it's not so easy.
The probliem is; Now there's no way to know what prefix number there was before since it has been stripped away from the query string. So I need to send it somehow along in the "background".
One very bad solution I came up with was to transform the navigation link into a form button and just _POST the prefix interger along with the form. At fist it sounded like a nice solution, but then I realized that once a user refreshes their page, it didn't look very good. And after all, that's not what forms are for either...
Any good solutions out there?
Or some other and better way for dealing with this?
There are two ways to keep that number saved, you can use cookies or php session variables.
But in this case, if user first enter the url in the browser or in a new browser, then he should be taken to default number.
Like you have:
1_first-page.php
2_first-page.php
3_first-page.php
If user enter the url like: domain.com/?page=first-page, you have to take him to 1_first-page.php to any number which you want to be default.
My site is organized into topics. Users can switch between topics on any page, at any time. I would like to be able to pass this topic along from page to page. I am guessing this should be done in a php post or get variable. I can grab the topic from the post or get variable and then run the rest of my site. However, this seems like it requires a form on every page to pass along this variable. As of now, the only way I have passed post or get variables was from forms on the previous page. I have never passed along these variables over several pages. Will I need a form on every page to pass these variables? Also, is this the standard way of doing this?
You should probably use GET, because it sounds like you're just trying to display different information, and POST is supposed to be for performing changes or actions.
If you decide to use GET variables, all you have to do is append them to the end of the link's href:
MORE BANANAS
the least overhead method of doing this would be to add some javascript that sets a cookie each time someone navigates to a new topic. This would assume you can select somehow all links that match topics (presumably trough classes)
A better method - because of compatibility,reliability and overhead - but not necessarily feasible, if a large number of links needs changing, is to use GET requests, as another poster suggested
You can create a helper function to generate your anchor tags and just append any existing query string to it, so instead of this:
Foobar
you would do this:
<?php echo anchor('page2.php','Foobar'); ?>
where your function would look like this:
/**
* Function creates an anchor tag and optionally
* appends an existing query string
* #param string $url
* #param string $txt
* #param bool $attach_qs Whether or not to follow a query string
*/
function anchor($url, $txt, $attach_qs = true)
{
$qs = '';
if ($attach_qs === true) {
$qs = (!empty($_SERVER['QUERY_STRING'])) ? '?' . $_SERVER['QUERY_STRING'] : '';
}
return '' . $txt . '';
}
Kolink's suggestion of placing the topic in via a PHP echo statement for every URL would certainly work. There is however, another option that I am surprised hasn't come up yet.
You could use PHPs Session Manager to store the variable. It is similar to using cookies; however, it is only temporary (limited to the session). Where a cookie can be persistent over multiple sessions.
<?php
// use this code before the page is generated, before the topic is decided.
session_start();
if (isset($_GET['topic']) && $_GET['topic'] != $_SESSION['topic']) {
// GET['topic'] is set, session variable does not match
// you may want to sanitize or limit what can be passed via ?topic=
$_SESSION['topic'] = $_GET['topic'];
} else if (isset($_SESSION['topic'])) {
// Session topic is not empty, run code to display appropriate content
} else {
// No topic is set, display default
}
?>
It's by no means the only solution, but it does give you an extra option.