Add Search To A Hugo Site

As with many sites these days, once they get beyond a certain size then search becomes an essential part of them. It can however we one of the trickier parts of a statically built websites because without a back-end to do the search for you then it has to be done client-side in the web browser.

Luckily solutions to this problem already exist and we show off one these solutions below which uses both FuseJS and MarkJS. This code is based on a gist by eddiewebb - but is build with “vanilla” JavaScript instead of jQuery.

HTML - Search Form

We need a html form to search with. This can either be on a search page of it’s own, any type of page or all pages as it works by submitting the form to the /search endpoint. We need the id on the input to put the search query back in it when it loads.

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<form action="/search" method="GET">
    <input type="search" name="q" id="search-query" placeholder="Search....">
    <button type="submit">Search</button>
</form>

Page - content/search/_index.md

Create a page for us to use as our search form and search results page. We set the layout to search and then create this layout to give us the ability to easily edit the html.

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---
title: "Search"
sitemap:
  priority : 0.1
layout: "search"
---

Layout - layout/_default/search.html

Our search page here contains a <div> element for us to add our results into, as well as a <div> element to store our loading message. In the layout we also define a template which we later use to populate a single search result entry. Finally, we load our JS libraries (from a cdn in this example, but feel free to self-host).

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{{ define "main" }}

<main>
    <div id="search-results"></div>
    <div class="search-loading">Loading...</div>

    <script id="search-result-template" type="text/x-js-template">
    <div id="summary-${key}">
        <h3><a href="${link}">${title}</a></h3>
        <p>${snippet}</p>
        <p>
            <small>
                ${ isset tags }Tags: ${tags}<br>${ end }
            </small>
        </p>
    </div>
    </script>

    <script src="https://cdnjs.cloudflare.com/ajax/libs/fuse.js/3.2.0/fuse.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/mark.js/8.11.1/mark.min.js"></script>
</main>

{{ end }}

JS

The main chunk of the code comes as JavaScript for this as we need to bring it altogether. We read the url parameters to get the query then pass that to FuseJS and MarkJS the write the results back to our page.

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var summaryInclude = 60;
var fuseOptions = {
    shouldSort: true,
    includeMatches: true,
    threshold: 0.0,
    tokenize: true,
    location: 0,
    distance: 100,
    maxPatternLength: 32,
    minMatchCharLength: 1,
    keys: [
        {name: "title", weight: 0.8},
        {name: "contents", weight: 0.5},
        {name: "tags", weight: 0.3},
        {name: "categories", weight: 0.3}
    ]
};

// =============================
// Search
// =============================

var inputBox = document.getElementById('search-query');
if (inputBox !== null) {
    var searchQuery = param("s");
    if (searchQuery) {
        inputBox.value = searchQuery || "";
        executeSearch(searchQuery, false);
    } else {
        document.getElementById('search-results').innerHTML = '<p class="search-results-empty">Please enter a word or phrase above, or see <a href="/tags/">all tags</a>.</p>';
    }
}

function executeSearch(searchQuery) {

    show(document.querySelector('.search-loading'));

    fetch('/index.json').then(function (response) {
        if (response.status !== 200) {
            console.log('Looks like there was a problem. Status Code: ' + response.status);
            return;
        }
        // Examine the text in the response
        response.json().then(function (pages) {
            var fuse = new Fuse(pages, fuseOptions);
            var result = fuse.search(searchQuery);
            if (result.length > 0) {
                populateResults(result);
            } else {
                document.getElementById('search-results').innerHTML = '<p class=\"search-results-empty\">No matches found</p>';
            }
            hide(document.querySelector('.search-loading'));
        })
        .catch(function (err) {
            console.log('Fetch Error :-S', err);
        });
    });
}

function populateResults(results) {

    var searchQuery = document.getElementById("search-query").value;
    var searchResults = document.getElementById("search-results");

    // pull template from hugo template definition
    var templateDefinition = document.getElementById("search-result-template").innerHTML;

    results.forEach(function (value, key) {

        var contents = value.item.contents;
        var snippet = "";
        var snippetHighlights = [];

        snippetHighlights.push(searchQuery);
        snippet = contents.substring(0, summaryInclude * 2) + '&hellip;';

        //replace values
        var tags = ""
        if (value.item.tags) {
            value.item.tags.forEach(function (element) {
                tags = tags + "<a href='/tags/" + element + "'>" + "#" + element + "</a> "
            });
        }

        var output = render(templateDefinition, {
            key: key,
            title: value.item.title,
            link: value.item.permalink,
            tags: tags,
            categories: value.item.categories,
            snippet: snippet
        });
        searchResults.innerHTML += output;

        snippetHighlights.forEach(function (snipvalue, snipkey) {
            var instance = new Mark(document.getElementById('summary-' + key));
            instance.mark(snipvalue);
        });

    });
}

function param(name) {
    return decodeURIComponent((location.search.split(name + '=')[1] || '').split('&')[0]).replace(/\+/g, ' ');
}

function render(templateString, data) {
    var conditionalMatches, conditionalPattern, copy;
    conditionalPattern = /\$\{\s*isset ([a-zA-Z]*) \s*\}(.*)\$\{\s*end\s*}/g;
    //since loop below depends on re.lastInxdex, we use a copy to capture any manipulations whilst inside the loop
    copy = templateString;
    while ((conditionalMatches = conditionalPattern.exec(templateString)) !== null) {
        if (data[conditionalMatches[1]]) {
            //valid key, remove conditionals, leave contents.
            copy = copy.replace(conditionalMatches[0], conditionalMatches[2]);
        } else {
            //not valid, remove entire section
            copy = copy.replace(conditionalMatches[0], '');
        }
    }
    templateString = copy;
    //now any conditionals removed we can do simple substitution
    var key, find, re;
    for (key in data) {
        find = '\\$\\{\\s*' + key + '\\s*\\}';
        re = new RegExp(find, 'g');
        templateString = templateString.replace(re, data[key]);
    }
    return templateString;
}

// Helpers
var show = function (elem) {
    elem.style.display = 'block';
};
var hide = function (elem) {
    elem.style.display = 'none';
};

The Data - layouts/_default/index.json

All the work we’ve done up until now has been front-end workings, but we also build a index.json file as our data source (which is fetched from the JS).

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{{- $.Scratch.Add "index" slice -}}
{{- range .Site.RegularPages -}}
    {{- $.Scratch.Add "index" (dict "title" .Title "tags" .Params.tags "categories" .Params.categories "contents" .Plain "permalink" .Permalink) -}}
{{- end -}}
{{- $.Scratch.Get "index" | jsonify -}}

Config

Enable our index json file inside the config.toml file (in the root of your project).

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[outputs]
    home = ["HTML", "RSS", "JSON"]

Although there are quite a few steps to the setup, if you follow the changes above you should end up with a working search form (like we do on this site!) Any issues let us know in the comments.


Site illustrations (of Hugo the rabbit) drawn by Carina Roberts.