lavender.software/src/webring/webring.js

(function() {
    function getUID() {
        var array = new Uint8Array(8);
        window.crypto.getRandomValues(array);
        return Array.from(array).map(b => b.toString(16).padStart(2, "0")).join("");
    }

    const params = document.currentScript.dataset;
    const UID = getUID();

    const css = `
#--lavender-cssreset-${UID} {
	all: unset;
}

#--lavender-webring-container-${UID} {
	background-color: rgb(28, 23, 36);
	background-blend-mode: multiply;
	position: relative;

	background-color: ${params.backgroundColor || "purple"};
	color: ${params.textColor || "white"};
	text-shadow: 0px 1px 1px ${params.textShadowColor || "black"};
	padding: 1px;
	font-size: 16px;
	font-family: sans-serif;

	margin: 10px 0px;
}

#--lavender-webring-container-${UID} a {
	color: inherit !important;
}

#--lavender-webring-container-${UID}::before {
	display: block;
	content: ' ';
	top: 0; left: 0; bottom: 0; right: 0;
	position: absolute;
	box-sizing: border-box;
	pointer-events: none;
	border: 5px outset;
	opacity: 0.25;
	border-color: white black black white;
}

#--lavender-webring-container-${UID} #--lavender-webring-title-${UID} {
	margin: 10px 10px 0px;
	text-align: center;
	font-style: italic;
}

#--lavender-webring-container-${UID} #--lavender-webring-item-container-${UID} {
	display: flex;
	justify-content: space-around;
}

@media (max-width: 600px) {
	#--lavender-webring-container-${UID} #--lavender-webring-item-container-${UID} {
		flex-direction: column;
	}
}

#--lavender-webring-container-${UID} .--lavender-webring-items-${UID} {
	font-size: 14px;
	display: block;
	text-align: center;
	padding: 0px;
	margin: 10px 10px 8px;
	flex: 1;
}

#--lavender-webring-container-${UID} #--lavender-webring-item-1-${UID}::before {
	display: inline;
	content: '\\2190\\00a0';
}
#--lavender-webring-container-${UID} #--lavender-webring-item-3-${UID}::after {
	display: inline;
	content: '\\00a0\\2192';
}
`;

    const webring_content = `
<div id="--lavender-cssreset-${UID}">
<div id="--lavender-webring-container-${UID}">
	<p id="--lavender-webring-title-${UID}">This website is a part of the Lavender Software webring</p>
	<div id="--lavender-webring-item-container-${UID}">
		<a class="--lavender-webring-items-${UID}" id="--lavender-webring-item-1-${UID}"></a>
		<a class="--lavender-webring-items-${UID}" id="--lavender-webring-item-2-${UID}"></a>
		<a class="--lavender-webring-items-${UID}" id="--lavender-webring-item-3-${UID}"></a>
	</div>
</div>
</div>
`;

    function renderIdx(data, element, idx) {
        idx = (idx + data.length) % data.length;

        datum = data[idx];
        element.textContent = datum.name;
        element.href = datum.url;
    }

    function getElementByPostfixedId(path) {
        return document.getElementById(path + "-" + UID);
    }

    function renderContent(currentScript, data) {
        const params = currentScript.dataset;

        var headstyle = document.createElement('style');
        headstyle.innerHTML = css;
        document.head.appendChild(headstyle);

        currentScript.insertAdjacentHTML("afterend", webring_content);

        const container = getElementByPostfixedId('--lavender-webring-container');

        const item1 = getElementByPostfixedId('--lavender-webring-item-1');
        const item2 = getElementByPostfixedId('--lavender-webring-item-2');
        const item3 = getElementByPostfixedId('--lavender-webring-item-3');

        const id = params.siteId;
        var idindex = -1;

        for (var i = 0; i < data.length; i++) {
            if (data[i].id == id) {
                idindex = i;
            }
        }

        if (idindex == -1) {
            item2.textContent = "this site was not found in the list. please check that you don't have any typos in the id!";
            return;
        }

        if ("hideTitle" in params) {
            getElementByPostfixedId('--lavender-webring-title').style.display = 'none';
        }

        renderIdx(data, item1, idindex - 1);
        renderIdx(data, item2, idindex);
        renderIdx(data, item3, idindex + 1);
    }

    const currentScript = document.currentScript;
    if (currentScript) {
      fetch("https://lavender.software/webring/data.json").then(function(response) {
            return response.json();
        }).then(function(data) {
            renderContent(currentScript, data);
        });
    } else {
        console.log("cannot locate document.currentScript element. aborting...");
    }

})();