Get link to next page in post pagination (Wordpress) - php

I know about the link pages function (https://developer.wordpress.org/reference/functions/wp_link_pages/)
to output a link to the next and previous part of paginated posts. But this always automatically does the output. Is there a variable I can access (or a function that returns) the link only, so I can continue coding with it?

Yes, previous_post_link and next_post_link will allow this. See https://codex.wordpress.org/Function_Reference/previous_post_link and https://codex.wordpress.org/Function_Reference/next_post_link.
EDIT: I see that's not exactly what you need. It looks like you can set arguments to wp_link_pages to define the output. For example, this should provide clear output and just the link:
wp_link_pages(array('before'=>'',
'after'=>'',
'link_before'=>'',
'link_after'=>'',
'nextpagelink'=>'',
'previouspagelink'=>'',
'echo'=>'0'));
The 'echo' argument appears to specify whether or not to print the html or just return it, so you may also be able to just set that to 0 and parse your output from there. Hope this helps!

Related

Smarty: How to read a {$var} stored in the database?

I use codeigniter with smarty.
I have a variable stored in the db called $serverName. I want to expand it to its actual value "Pedrosite". But when the page is loaded, it displays exactly {$serverName} and not the value.
So I found this solution on stackoverflow, using smarty's fetch function:
$data['content'] contains the text from the database.
$data['content'] = $this->CI->smarty->fetch('string:'.$data['content']);
With that, I can display the smarty vars, like: {$smarty.const.FCPATH}
But none of my custom $vars while they can be shown in a regular template (.tpl).
So I found this workaround that looks very hacky to me:
$this->CI->smarty->assign('serverName', $this->CI->config->item('server_name'));
I can put this in one of my __construct function and then it will affect the whole site, and then it loads properly. But I'm not sure it's the right way to proceed at all.
I don't really understand your question, but, if you have your variable $serverName and it content "Pedrosite" you can display it like that :
$this->smarty->assign('serverName' , $serverName);
$this->smarty->view('/modules/xxxxxx');
And display it in your .html file for example :
<p>{$serverName}</p>

How to make dynamic links in php without eval()

I am using wordpress for a web site. I am using snippets (my own custom php code) to fetch data from a database and echo that data onto my web site.
if($_GET['commentID'] && is_numeric($_GET['commentID'])){
$comment_id=$_GET['commentID'];
$sql="SELECT comments FROM database WHERE commentID=$comment_id";
$result=$database->get_results($sql);
echo "<dl><dt>Comments:</dt>";
foreach($result as $item):
echo "<dd>".$item->comment."</dd>";
endforeach;
echo "</dl>";
}
This specific page reads an ID from the URL and shows all comments related to that ID. In most cases, these comments are texts. But some comments should be able to point to other pages on my web site.
For example, I would like to be able to input into the comment-field in the database:
This is a magnificent comment. You should also check out this other section for more information
where getURLtoSectionPage() is a function I have declared in my functions.php to provide the static URLs to each section of my home page in order to prevent broken links if I change my URL pattern in the future.
I do not want to do this by using eval(), and I have not been able to accomplish this by using output buffers either. I would be grateful for any hints as to how I can get this working as safely and cleanly as possible. I do not wish to execute any custom php code, only make function calls to my already existing functions which validates input parameters.
Update:
Thanks for your replies. I have been thinking of this problem a lot, and spent the evening experimenting, and I have come up with the following solution.
My SQL "shortcode":
This is a magnificent comment. You should also check out this other section for more information
My php snippet in wordpress:
ob_start();
// All my code that echo content to my page comes here
// Retrieve ID from url
// Echo all page contents
// Finished generating page contents
$entire_page=ob_get_clean();
replaceInternalLinks($entire_page);
PHP function in my functions.php in wordpress
if(!function_exists("replaceInternalLinks")){
function replaceInternalLinks($reference){
mb_ereg_search_init($reference,"\[custom_func:([^\]]*):([^\]]*)\]");
if(mb_ereg_search()){
$matches = mb_ereg_search_getregs(); //get first result
do{
if($matches[1]=="getURLtoSectionPage" && is_numeric($matches[2])){
$reference=str_replace($matches[0],getURLtoSectionPage($matches[2]),$reference);
}else{
echo "Help! An unvalid function has been inserted into my tables. Have I been hacked?";
}
$matches = mb_ereg_search_regs();//get next result
}while($matches);
}
echo $reference;
}
}
This way I can decide which functions it is possible to call via the shortcode format and can validate that only integer references can be used.
I am safe now?
Don't store the code in the database, store the ID, then process it when you need to. BTW, I'm assuming you really need it to be dynamic, and you can't just store the final URL.
So, I'd change your example comment-field text to something like:
This is a magnificent comment. You should also check out this other section for more information
Then, when you need to display that text, do something like a regular expression search-replace on 'href="#comment-([0-9]+)"', calling your getURLtoSectionPage() function at that point.
Does that make sense?
I do not want to do this by using eval(), and I have not been able to accomplish this by using output buffers either. I would be grateful for any hints as to how I can get this working as safely and cleanly as possible. I do not wish to execute any custom php code, only make function calls to my already existing functions which validates input parameters.
Eval is a terrible approach, as is allowing people to submit raw PHP at all. It's highly error-prone and the results of an error could be catastrophic (and that's without even considering the possibly that code designed by a malicious attacker gets submitted).
You need to use something custom. Possibly something inspired by BBCode.

How to remove any given $_GET variable from URL with PHP?

I'm puttings filters in links with GET variables like this: http://example.com/list?size=3&color=7 and I'd like to remove any given filter parameter from URL whenever a different value for that particular filter is selected so that it doesn't, for example, repeat the color filter like so:
http://example.com/list?size=3&color=7&color=1
How can I if(isset($_GET['color'])) { removeGet('color'); } ?
You can use parse_url and parse_str to extract parameters like in example below:
$href = 'http://example.com/list?size=3&color=7';
$query = parse_url( $href, PHP_URL_QUERY );
parse_str( $query, $params );
// set custom paramerets
$params['color'] = 1;
// build query string
$query = http_build_query( $params );
// build url
echo explode( '?', $href )[0] . '?' . $query;
In this example explode() is used to extract the part of the url before the query string, and http_build_query to generate query string, you can also use PECL http_build_url() function, if you cannot use PECL use alternative like in this question.
You can't remove variables from GET request, just redirect to address without this var.
if (isset($_GET['color'])) {
header ('Location: http://www.example.com/list?size=' . $_GET['size']);
exit;
}
Note: in URL http://example.com/list?size=3&color=7&color=1 is just one $_GET['color'], not two. Only one of them is taken. You can check, is $_GET['key'] exists, but you don't know how many of them you have in your URL
So, assuming I'm understanding your question correctly.
Your situation is as follows:
- You are building URLs which you put into a webpage as a link ( <a href= )
- You are using the GET syntax/markup (URL?key=value&anotherkey=anothervalue) as a way to assign filters of some sort which the user then receives when they click on a given link
What you want is to be able to modify one of the items in your GET parameter list (http://example.com/list?size=3&color=7&color=1) so you have only one filter key but you can modify the filter value. So instead of the above you would start with: (http://example.com/list?size=3&color=7) but after changing the color 'filter' you would instead have http://example.com/list?size=3&color=1).
Additionally you want to do the above in PHP, (as opposed to JavaScript etc...).
There are a lot of ways to implement the change and the most effective way to do it depends on what you are already doing, most likely.
First, if you are dynamically producing the HTML markup which includes the links with the filter text, (which is what it sounds like), then it makes the most sense to create a PHP array to hold your GET parameters, then write a function that would turn those parameters into the GET string.
New filters would appear when a user refreshed the page, (because, if you are dynamically producing the HTML then a server request is required to rebuild the page).
IF, however, you want to update the link URLs on a live page WITHOUT a reload look into doing it with JavaScript, it will make your life easier.
NOTE: It is likely possible to modify the page, assuming the links are hard coded, & the page is hard coded markup, by opening the page as a file in PHP & making the appropriate change. It's my opinion that this would be a headache and not worth the time & effort AND it would still require a page reload (which you could NOT trigger yourself).
Summary
If you are writing dynamic pages with PHP it shouldn't be a big deal, just create a structure (class or array) and a method/function to write that structure out as a GET string. The structure could then be modified according to your desire before generating the page.
If, however, you are dealing with a static page, I recommend JavaScript (either creating js structures to allow a user to dynamically select filters or utilizing AJAX to build new GET parameter lists with PHP and send that back to the javascript).
(NOTE: I am reminded that I have done something along the lines of modifying links on-the-fly for existing pages by intercepting them before they are displayed to the user [using PHP] but my hands were tied in other areas and I would not recommend it if you have a choice AND it should be noted that this still required a reload...)
Try doing something like this in your back-end script:
$originalValues=array();
foreach($_GET as $filter=>$value)
{
if(empty($originalValues[$filter]))
$originalValues[$filter] = $value;
}
This may do what you want, but it feels hackish. You may want to revise your logic.
Good luck!
just put a link/button send the user to index... like this.
<a class="btn btn-primary m-1" href="http:yoururl/index.php" role="button">Limpar</a>

How to display content based on the URL

I'm learning PHP and MySQL and I have a question. I've seen that a lot of sites use this, for example:
http://www.example.com/index.php?product_id=8
or
http://www.example.com/index.php?cattegory=headphones
If you change the values in the URL, the content the page displays changes, so I would like to know how to use that in my webpage, thanks!
You can check for the GET parameter included in the url...
if($_GET['product_id' == 8]) { ... }

FBML to PHP variable

hello how to set a value in php variables from fbml(facebook markup language)
<fb:comments-count href=http://domain.com/view/24></fb:comments-count>
please share your idea :)
I think what you're trying to do is get the number of comments for a certain page. In that case you shouldn't do it via FBML but instead make a REST call: http://developers.facebook.com/docs/reference/fbml/comments_(XFBML)/
You'll see that you can do a call along the lines of https://api.facebook.com/method/fb:comments?access_token=https://api.facebook.com/method/fb:comments?access_token=FOO

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