How to create a search page for a static website with vanilla JS

One of the biggest missing features from most static site generators (like Hugo, 11ty, and Jekyll, ) is that they lack built-in search.

Database-driven platforms like WordPress make a server call and search the database to find matching content. Static websites have no database to query.

Today, I’m going to share how I built the search functionality for my site with vanilla JS. Let’s dig in!

Quick aside: done-for-you alternative

If you don’t want to roll-your-own search functionality, Algolia and ElasticSearch are two done-for-you search vendors.

They both offer free tiers, as well as paid versions with more advanced features.

But, because I like to do things the hard way have more control over the user experience, I wrote my own search functionality instead of using one of them.

The Search Form

My search functionality starts as a progressively enhanced search form.

<form action="https://duckduckgo.com/" method="get" id="form-search">
    <label for="input-search">Enter your search criteria:</label>
    <input type="text" name="q" id="input-search">
    <input type="hidden" name="sites" value="YourAwesomeWebsite.com">
    <button>Search</button>
</form>

If the JavaScript fails (or the user tries to search before it loads), this will open up Duck Duck Go and search for articles only on my site.

Be sure to replace YourAwesomeWebsite.com with the actual URL to your site.

We’ll also add two additional elements to the page. The #search-results element is where we’ll inject the actual search results. The #search-status element is where we’ll display the number of items found.

We want this to announce to screen readers, so we’ll also add the [role="status"] attribute to it.

<div id="search-status" role="status"></div>
<div id="search-results"></div>

Creating a search index

In order to search your site, we need to create an index of content.

The process for this varies from one static site generator to another, but the end result is the same. You want to generate an array of all of the searchable content on your site.

Some people create an external JSON file for this, but I prefer to embed it as a JavaScript variable directly on the search page. it looks like this:

let searchIndex = [
    {
        title: "My awesome article",
        date: "December 18, 2018",
        url: "https://gomakethings.com/my-awesome-article",
        content: "The full text of the content...",
        summary: "A short summary or preview of the content (can also be a clipped version of the first few sentences)..."
    },
    // More content...
];

We can use this to both search for articles and generate results on the page.

Creating a search function

Next, let’s create a function to actually do the searching. This can be an IIFE or a named function. We just want a way to scope our code.

(function () {
    // Code will go here...
})();

Next, we need to get the needed elements from the DOM. We can do that with the document.querySelector() method.

(function () {

    // Get the DOM elements
 let form = document.querySelector('#form-search');
    let input = document.querySelector('#input-search');
    let resultList = document.querySelector('#search-results');
    let searchStatus = document.querySelector('#search-status');

})();

If we can’t find any of them, or if the searchIndex doesn’t exist, we’ll return to stop the function from doing anything else.

(function () {

    // Get the DOM elements
 let form = document.querySelector('#form-search');
    let input = document.querySelector('#input-search');
    let resultList = document.querySelector('#search-results');
    let searchStatus = document.querySelector('#search-status');

    // Make sure required content exists
 if (!form || !input || !resultList || !searchStatus || !searchIndex) return;

})();

Running a search

Next, we need to detect when the user searches for something. To do that, we’ll listen for submit events on the form element.

(The rest of the code all happens inside the IIFE, but I’m sharing just the relevant stuff to make it easier to read.)

// Create a submit handler
form.addEventListener('submit', submitHandler);

In the submitHandler() function, we’ll use the event.preventDefault() method to stop the form from submitting to Duck Duck Go. Then, we’ll pass the input.value into a search() function that will actually look for results.

/**
 * Handle submit events
 */
function submitHandler (event) {
    event.preventDefault();
    search(input.value);
}

Searching for results

Here’s where stuff gets a bit messy.

Rather than search for complete phrases, we want to look at each word from the search query, and look for it in the titles and content of our articles. We want to ignore case, and we probably also want to ignore common words like a, an, and the.

I use the String.toLowerCase() method to convert the query to lowercase. Then, I use the String.split() method to convert it to an array, with each word as its own item.

/**
 * Search for matches
 * @param  {String} query The term to search for
 */
function search (query) {

    // Create a regex for each query
 let regMap = query.toLowerCase().split(' ');
}

Next, I created an array of stopWords: words that should be ignored. I found a list on the web, and modified it based on the type of content I have on my site.

For example, I added vanilla, javascript, and js to my list, since almost every article I write includes those words heavily, making them meaningless.

let stopWords = ['a', 'an', 'and', 'are', 'aren\'t', 'as', 'by', 'can', 'cannot', 'can\'t', 'could', 'couldn\'t', 'how', 'is', 'isn\'t', 'it', 'its', 'it\'s', 'that', 'the', 'their', 'there', 'they', 'they\'re', 'them', 'to', 'too', 'us', 'very', 'was', 'we', 'well', 'were', 'what', 'whatever', 'when', 'whenever', 'where', 'with', 'would', 'yet', 'you', 'your', 'yours', 'yourself', 'yourselves', 'the', 'vanilla', 'javascript', 'js'];

Back in my search() function, I use the Array.filter() method to remove any word that’s an empty string or part of the stopWords array.

I use the Array.includes() method to check if the word is in stopWords.

Finally, I use the Array.map() method an new RegExp() constructor to create an array of regex searches from my query.

/**
 * Search for matches
 * @param  {String} query The term to search for
 */
function search (query) {

    // Create a regex for each query
 let regMap = query.toLowerCase().split(' ').filter(function (word) {
        return word.length && !stopWords.includes(word);
    }).map(function (word) {
        return new RegExp(word, 'i');
    });

}

Doing the actual search

Now that I have my regex patterns all setup, I can actually do the search.

For this, I use the Array.reduce() method on my searchIndex. I want to create a new array containing just matching items. I also want to include a priority rating, so that more closing matching items are shown higher in the results.

I pass in an empty array ([]) as my accumulator, which I assign to the results parameter.

/**
 * Search for matches
 * @param  {String} query The term to search for
 */
function search (query) {

    // Create a regex for each query
 // ...

    // Get and sort the results
 let results = searchIndex.reduce(function (results, article, index) {
        // Do stuff...
 }, []);
}

Inside the callback function, I create a priority variable with a value of 0.

Then, I loop through each item in my regMap using a for...of loop. I use the RegExp.test() method to look for matches in the article.title, and RegExp.match() method to look for matches in the article.content.

I give more weight to the title than content. If there’s a match, I increase the priority by 100. For every match in content, I increase the priority by 1.

/**
 * Search for matches
 * @param  {String} query The term to search for
 */
function search (query) {

    // Create a regex for each query
 // ...

    // Get and sort the results
 let results = searchIndex.reduce(function (results, article, index) {

        // Setup priority count
     let priority = 0;

        // Assign priority
     for (let reg of regMap) {
            if (reg.test(article.title)) { priority += 100; }
            let occurences = article.content.match(reg);
            if (occurences) { priority += occurences.length; }
        }

    }, []);
}

If priority is greater than 0, I use the Array.push() method to add a new object ({}) to the results array.

I include the priority and article as properties. Then, I return the results.

/**
 * Search for matches
 * @param  {String} query The term to search for
 */
function search (query) {

    // Create a regex for each query
 // ...

    // Get and sort the results
 let results = searchIndex.reduce(function (results, article, index) {

        // Setup priority count
     let priority = 0;

        // Assign priority
     for (let reg of regMap) {
            if (reg.test(article.title)) { priority += 100; }
            let occurences = article.content.match(reg);
            if (occurences) { priority += occurences.length; }
        }

        // If any matches, push to results
     if (priority > 0) {
            results.push({
                priority: priority,
                article: article
            });
        }

        return results;

    }, []);
}

Finally, I use the Array.sort() method to order the results by article priority. Items with the highest priority show up first.

Then, I pass the results into a showResults() method that renders them into the UI.

/**
 * Search for matches
 * @param  {String} query The term to search for
 */
function search (query) {

    // Create a regex for each query
 // ...

    // Get and sort the results
 let results = searchIndex.reduce(function (results, article, index) {
        // ...
 }, []).sort(function (article1, article2) {
        return article2.priority - article1.priority;
    });

    // Display the results
 showResults(results);

}

Rendering search results

Inside the showResults() method, I do a quick check to see if their are any results to show.

If there are, I inject a message into the searchStatus element that shares how many matches were found. This also gets read aloud by screen readers.

Then, I use the results to create an HTML string with the title and a link to the article. The appearance of this varies from one site to another, but you can style it however you want.

/**
 * Show the search results in the UI
 * @param  {Array}  results The results to display
 */
function showResults (results) {
    if (results.length) {
        searchStatus.innerHTML = `<p>Found ${results.length} matching articles</p>`;
        resultList.innerHTML = myTemplate(results);
    }
}

If there are no results, I clear the resultList element and show a message saying there were no matches.

/**
 * Show the search results in the UI
 * @param  {Array}  results The results to display
 */
function showResults (results) {
    if (results.length) {
        searchStatus.innerHTML = `<p>Found ${results.length} matching articles</p>`;
        resultList.innerHTML = myTemplate(results);
    } else {
        searchStatus.innerHTML = '<p>Sorry, no matches were found.</p>';
        resultList.innerHTML = '';
    }
}

What else?

Tomorrow, I’ll show you how I update the URL with the search query, and run a search automatically on page load if there’s a query in the URL.

This let’s people bookmark searches.