feat: prima versione del plugin, blocco e shortcode con iframe stampato lato server

includes/render.php

@@ -0,0 +1,172 @@
+<?php
+/**
+ * Builds the widget URL and renders the iframe. Shared by the shortcode and
+ * the block: both end up here, so there is a single place where parameters are
+ * sanitised and a single place where markup is produced.
+ *
+ * @package PiazzaInFesta
+ */
+
+defined( 'ABSPATH' ) || exit;
+
+/**
+ * Default values for every supported parameter.
+ *
+ * @return array<string, string>
+ */
+function pinfesta_defaults() {
+	return array(
+		'comuni'    => '',
+		'regione'   => '',
+		'categoria' => '',
+		'limite'    => '5',
+		'tema'      => 'chiaro',
+		'colore'    => '',
+		'titolo'    => '',
+		'altezza'   => '320',
+	);
+}
+
+/**
+ * Categories accepted by the service. Anything else is dropped instead of
+ * being forwarded, so a typo shows every event rather than none.
+ *
+ * @return string[]
+ */
+function pinfesta_categorie() {
+	return array(
+		'religioso',
+		'sagra_enogastronomica',
+		'musica_concerto',
+		'culturale_mostra',
+		'incontro_conferenza',
+		'fiera_mercato',
+		'mercatini',
+		'sportivo',
+		'natura_escursione',
+		'spettacolo',
+		'teatro',
+		'cinema',
+		'bambini_famiglie',
+		'istituzionale',
+		'altro',
+	);
+}
+
+/**
+ * Cleans a comma separated list of town identifiers (the slug you see in the
+ * address of a town page, for instance "la-morra"). Twelve at most, which is
+ * what the service accepts.
+ *
+ * @param string $raw Raw attribute value.
+ * @return string Normalised list, empty when nothing survives.
+ */
+function pinfesta_clean_comuni( $raw ) {
+	$out = array();
+
+	foreach ( explode( ',', (string) $raw ) as $item ) {
+		$slug = sanitize_title( trim( $item ) );
+
+		if ( '' !== $slug ) {
+			$out[] = $slug;
+		}
+	}
+
+	return implode( ',', array_slice( array_unique( $out ), 0, 12 ) );
+}
+
+/**
+ * Turns the parameters into the URL of the widget page on the service.
+ *
+ * @param array $args Parameters, already merged with the defaults.
+ * @return string
+ */
+function pinfesta_build_url( $args ) {
+	$query = array();
+
+	$comuni = pinfesta_clean_comuni( $args['comuni'] );
+
+	if ( '' !== $comuni ) {
+		$query['comune'] = $comuni;
+	} elseif ( '' !== $args['regione'] ) {
+		$query['regione'] = sanitize_text_field( $args['regione'] );
+	}
+
+	if ( in_array( $args['categoria'], pinfesta_categorie(), true ) ) {
+		$query['categoria'] = $args['categoria'];
+	}
+
+	$limite = absint( $args['limite'] );
+
+	if ( $limite > 0 ) {
+		$query['limite'] = min( $limite, 20 );
+	}
+
+	if ( 'scuro' === $args['tema'] ) {
+		$query['tema'] = 'scuro';
+	}
+
+	$colore = sanitize_hex_color( $args['colore'] );
+
+	if ( $colore ) {
+		// Without the hash: add_query_arg() leaves "#" as it is, and a bare "#"
+		// in a URL opens the fragment, which would swallow this parameter and
+		// every parameter after it. The service accepts the six digits alone.
+		$query['accent'] = ltrim( $colore, '#' );
+	}
+
+	$titolo = sanitize_text_field( $args['titolo'] );
+
+	if ( '' !== $titolo ) {
+		$query['titolo'] = $titolo;
+	}
+
+	// Service key: optional. It only tells the service that this site may ask
+	// for the version without the Piazza in Festa credit line; every feature of
+	// this plugin works exactly the same with or without it.
+	$chiave = pinfesta_get_option( 'chiave' );
+
+	if ( '' !== $chiave ) {
+		$query['chiave']  = $chiave;
+		$query['marchio'] = '0';
+	}
+
+	return add_query_arg( $query, pinfesta_base_url() . '/embed' );
+}
+
+/**
+ * Renders the widget.
+ *
+ * An iframe, on purpose: the CSS of the host site cannot break the widget and
+ * the widget cannot break the host site. The height arrives from the framed
+ * page via postMessage (assets/js/resize.js), so nobody has to guess it; the
+ * `altezza` parameter is only the starting height, and what visitors see when
+ * JavaScript is off.
+ *
+ * @param array $args Parameters, already merged with the defaults.
+ * @return string HTML.
+ */
+function pinfesta_render_iframe( $args ) {
+	$args = wp_parse_args( $args, pinfesta_defaults() );
+
+	if ( '' === pinfesta_clean_comuni( $args['comuni'] ) && '' === trim( (string) $args['regione'] ) ) {
+		if ( ! current_user_can( 'edit_posts' ) ) {
+			return '';
+		}
+
+		return '<p class="pinfesta-empty">' . esc_html__( 'Piazza in Festa: set at least one town or a region.', 'piazza-in-festa' ) . '</p>';
+	}
+
+	wp_enqueue_style( 'pinfesta-widget' );
+	wp_enqueue_script( 'pinfesta-resize' );
+
+	$altezza = absint( $args['altezza'] );
+	$altezza = ( $altezza >= 120 && $altezza <= 4000 ) ? $altezza : 320;
+
+	return sprintf(
+		'<iframe class="pinfesta-embed" src="%1$s" title="%2$s" height="%3$d" loading="lazy" scrolling="no" referrerpolicy="no-referrer-when-downgrade"></iframe>',
+		esc_url( pinfesta_build_url( $args ) ),
+		esc_attr__( 'Upcoming local events', 'piazza-in-festa' ),
+		$altezza
+	);
+}