Auto Populate Taxonomy Term based on Custom value from URL

Hello Wordnow!

many thanks for your appreciation and postive feedback!
Please don’t forget to leave a quick review to the plugin if you enjoy it. it is really important for me. ??

What you need to do can be easily achieved using one of the plugin’s filters.
the quickest way would be if your url pass the Term ID rather than the Term Slug.
if you can set it up in that way, you can just add this function to your functions.php

/**
 * FILTER POSTS BASED ON TERM PASSED BY THE URL
 *
 * the variable MUST be the term ID
 * the filter assumes that the correct Taxonomy is already set within the widget options
 *
 * if no variable is passed, the filter will simply return the same instance
 *
 */
add_filter( 'pbytax_prepare_instance', 'pbytax_filter_by_url_var_term', 11, 3 );

function pbytax_filter_by_url_var_term( $new_instance, $instance, $widget_num ){
	// get the variable from the url
	$url_term = $_GET['countrycode'];

	// if we got something, set this value as filter_term for the widget
	if ( isset($url_term) && !empty($url_term) ){

		$new_instance['filter_term'] = intval($url_term);

	}

	// return the instance
	return $new_instance;

}

but if for you is important to have the term slug in the url, then we have to hook to the $args and change them to accept a slug rather than the expected ID.
it’s still pretty easy though, and you just have to add this function instead:

/**
 * FILTER POSTS BASED ON TERM PASSED BY THE URL
 *
 * the variable MUST be the slug of the term
 * the filter assumes that the correct Taxonomy is already set within the widget options
 *
 * if no variable is passed, or no tax_query was set from the widget options,
 	the filter will simply return the same $args
 *
 */

add_filter( 'pbytax_query_args', 'pbytax_filter_by_url_var_term', 11, 3 );

function pbytax_filter_by_url_var_term( $pbytax_args, $instance, $widget_num ){
	// get the variable from the url
	$url_term = $_GET['countrycode'];

		// if we got something, ensure that we also have a tax_query set into our query args
		if ( isset($url_term) && !empty($url_term) && $pbytax_args['tax_query'] ){

			// set the field to be "slug" and the terms to be the string passed by the url
			$pbytax_args['tax_query']['field'] = "slug";
			$pbytax_args['tax_query']['terms'] = $url_term;

		}

	//return the args
	return $pbytax_args;

}

let me know if it works or if you have doubts!
cheers!

Thank-you very much for your quick response!
I’m not sure which of the options I should be using that you gave me, so here is some more detail.
I have your widget setup like this:
Post Type: post
Taxonomy: post_country (my custom taxonomy)
Pull from this term: This is where I want to have the widget always replace this value with the url variable I’m passing, which is the countrycode like “FR” for France. So I want to literally use the url variable as the one and only taxonomy term/value to filter by.

Hi there!

I’m sorry if I confused you, I’ll try to be more clear.

the point is all about what will you pass with the url. will it be the term slug or term id?

I assume that “FR” is the “term name”, and the “term slug” is probably “fr”. Am I correct?

if you go to your taxonomy admin page, where you have the list of all your country terms, you will notice that there is a column called “slug”.
that is the value you will have to pass within the url if you want to use the SECOND FUNCTION.

instead, if you click to edit one of your terms in admin, and then look the url of the page, you will see that at one point there is
tag_ID=
the number after that = is the ID of the term you are viewing.
if you pass this value within your url, then you’d use the FIRST FUNCTION.

the important thing is that you shouldn’t pass the “Term Name” in any case, because it is not a valid parameter for the query.

let me know if you still have doubts!

p.s. with both those functions, you can set any term in the widget option, and the filter will overwrite it and put the one passed by the url.

Ok, I hope I’m getting close now. I confirmed that what I am passing is the “slug” which will now be, for example, “fr” for France (not the “FR” I had before). I have placed the SECOND FUNCTION in the functions.php file, but nothing seems to be happening. I put the code in the main functions.php in the wp-includes directory. Is this the right functions.php to put it in versus the one for my theme?
It seems to be not seeing the new function as everything is working like it did before where it is taking what the “Pull from this term” based on what I select in the widget, not what is passed in the url.
If I’m putting the code in the right functions.php file, do I need to do anything with clearing cache or anything else to ensure it is loading?
One other question: I notice in your code you say, “if no variable is passed, or no tax_query was set from the widget options, the filter will simply return the same $args”. So if that is the case, what will be the result if a wrong or no value is found?
Thanks again for helping me figure this out.

hi there!

you have to put it in your theme’s functions.php, sorry if I haven’t specified it.
in any case, as a general must-do rule, remember to don’t ever edit wordpress core files. basically you should never edit anything outside of the themes folder. ??

then when you put the function in the correct position, this is what it’ll do
– every time you load a page where the widget is displayed, it will check if there is a value passed from the url for the var countrycode
– if there is any, it will ensure that you have set a taxonomy name in the widget options
– if everything is fine it will set the query to filter by that term slug

– if you haven’t set a taxonomy name the filter will be skipped and the widget will display as if the function didn’t exist
– if there isn’t a countrycode in the url, it will be skipped as well
– if you set a taxonomy name but it is incorrect, the query won’t find any post matching
– if the provided term slug doesn’t exists or it’s incorrect, simply the query won’t find any post matching and will be empty (the widget then output “no matches found”)

in any case, I haven’t tested the function, so please let me know if it doesn’t work after you put it in the theme’s functions.php
by the way, if you refresh the page a few times it should pick up the new filter straight away. ??

cheers

At this point, it looks like either the custom filter/function from you is not loading or it is not working. I’ve put it into the functions.php for the theme I’m running. All behavior seems to indicate that the widget is functioning just as if there is no custom function. I tried, for example to pass a slug that doesn’t exist and I still get the same results. I’ve chosen “any” for the “Pull from this term” value and no matter what I do, it is coming up with the results of that function. Any other way to ensure the custom function you gave me is loading and functioning?

Hi there!

I have to apologize but I’ve made a little error in the code… ??
I forgot that the tax_query contains a sub array, so I should have targetted the args variable like this
$pbytax_args[‘tax_query’][0][‘field’]

this is the corrected code, I’ve tested it in my dev website and it works now:

/**
 * FILTER POSTS BASED ON TERM PASSED BY THE URL
 *
 * the variable MUST be the slug of the term
 * the filter assumes that the correct Taxonomy is already set within the widget options
 *
 * if no variable is passed, or no tax_query was set from the widget options,
 	the filter will simply return the same $args
 *
 */

add_filter( 'pbytax_query_args', 'pbytax_filter_by_url_var_term', 11, 3 );

function pbytax_filter_by_url_var_term( $pbytax_args, $instance, $widget_num ){
	// get the variable from the url
	$url_term = $_GET['countrycode'];

		// if we got something, ensure that we also have a tax_query set into our query args
		if ( isset($url_term) && !empty($url_term) && $pbytax_args['tax_query'] ){

			// set the field to be "slug" and the terms to be the string passed by the url
			$pbytax_args['tax_query'][0]['field'] = "slug";
			$pbytax_args['tax_query'][0]['terms'] = $url_term;

		}

	//return the args
	return $pbytax_args;

}

Excuse me for the inconvenience!

cheers!

Awesome!!! It works. So much appreciate your perseverance and quick response in working with me to get this going. You’re widget with this customization will save so much coding and effort.

brilliant!

I’m glad it is being helpful for you! ??

please take 3 minutes to review the plugin and give me a rating. it is the best way to thank me.

cheers!