jekyll.lunr.js

var index = lunr(function() {
    this.field('title', {
        boost: 10
    })
    this.field('body')
    this.ref('id')
});

{% for post in site.posts %}
index.add({
    id: {{ post.date | date: "%Y%m%d" }},
    title: {{ post.title | jsonify }},
    body: {{ post.description | jsonify }}
});
{% endfor %}

var posts = [];
for(var key in index.documentStore.store) {
    posts.push(key);
};

function staticSearch(input) {
    // set display: block; to all of the posts
    posts.forEach(function(post) {
        document.getElementById(post).style.display = 'block';
    });

    // get the results and set the matches to zero
    var results = index.search(input.value),
        matches = [];

    results.forEach(function(result) {
        // get the ids of the posts that match the search and place them in the 'matches' array
        matches.push(result.ref);
    });

    posts.forEach(function(post) {
        // set display: none; to all of the posts
        document.getElementById(post).style.display = 'none';
    });

    if(matches.length === 0) {
        // no matches to the search
        document.getElementById('search-value').innerHTML = input.value;
        document.getElementById('search-no-results').style.display = 'block';
    }
    else {
        // set display: block; to all of the matches
        matches.forEach(function(match) {
            document.getElementById(match).style.display = 'block';
        });

        // hide the no-results box
        document.getElementById('search-no-results').style.display = 'none';
    }
};

function staticSearchReset() {
    posts.forEach(function(post) {
        // set display: block; to all of the posts
        document.getElementById(post).style.display = 'block';
    });

    // hide the no-results box
    document.getElementById('search-no-results').style.display = 'none';
};

var input = document.getElementById('search__input');

window.onkeydown = function(event) {
    if(input.value.length === 1 || input.value.length === 0) {
        // there is no input
        staticSearchReset();

        if(event.keyCode === 8 || event.keyCode === 46) {
            input.blur();
        }
    }
    else {
        // there is an input, do search
        staticSearch(input);
    }

    if(event.keyCode === 27) {
        input.blur();
    }
    else {
        input.focus();
    }
};