/**

* A simple JSON search

* Requires jQuery (v 1.7+)

*

* @author Mat Hayward - Erskine Design

* @author Rishikesh Darandale <Rishikesh.Darandale@gmail.com>

* @version 1.1

*/

/* ==========================================================================

Initialisation

========================================================================== */

var q, jsonFeedUrl = '/feeds/feed.json',

$searchForm = $('[data-search-form]'),

$searchInput = $('[data-search-input]'),

$resultTemplate = $('#search-result'),

$resultsPlaceholder = $('[data-search-results]'),

$foundContainer = $('[data-search-found]'),

$foundTerm = $('[data-search-found-term]'),

$foundCount = $('[data-search-found-count]'),

allowEmpty = true,

showLoader = true,

loadingClass = 'is--loading',

indexVar;

$(document).ready( function() {

// hide items found string

$foundContainer.hide();

// initiate search functionality

initSearch();

});

/* ==========================================================================

Search functions

========================================================================== */

/**

* Initiate search functionality.

* Shows results based on querystring if present.

* Binds search function to form submission.

*/

function initSearch() {

if(!sessionStorage.getItem('lunrIndex')) {

// get the data

getData();

} else {

// Get search results if q parameter is set in querystring

if (getParameterByName('q')) {

q = decodeURIComponent(getParameterByName('q'));

$searchInput.val(q);

execSearch(q);

}

}

// Get search results on submission of form

$(document).on('submit', $searchForm, function(e) {

e.preventDefault();

q = $searchInput.val();

execSearch(q);

});

}

/**

* Get the JSON data

* Get the generated feeds/feed.json file so lunr.js can search it locally.

* Store the index in sessionStorage

*/

function getData(indexVar) {

jqxhr = $.getJSON(jsonFeedUrl)

.done(function(loaded_data){

// save the actual data as well

sessionStorage.setItem('actualData', JSON.stringify(loaded_data));

// set the index fields

indexVar = lunr(function () {

this.field('id');

this.field('title');

this.field('content', { boost: 10 });

this.field('author');

loaded_data.forEach(function (doc, index) {

if ( doc.search_omit != 'true' ) {

// console.log('adding to index: ' + doc.title);

this.add($.extend({ 'id': index }, doc));

}

}, this)

});

// store the index in sessionStorage

sessionStorage.setItem('lunrIndex', JSON.stringify(indexVar));

// Get search results if q parameter is set in querystring

if (getParameterByName('q')) {

q = decodeURIComponent(getParameterByName('q'));

$searchInput.val(q);

execSearch(q);

}

})

.fail( function() {

console.log('get json failed…');

})

.always( function() {

console.log('finally…');

});

}

/**

* Get the search result from lunr

* @param {String} q

* @returns search results

*/

function getResults(q) {

var savedIndexData = JSON.parse(sessionStorage.getItem('lunrIndex'));

// console.log('Indexed var from sessionStorage: ' + savedIndexData);

return lunr.Index.load(savedIndexData).search(q);

}

/**

* Executes search

* @param {String} q

* @return null

*/

function execSearch(q) {

if (q != '' || allowEmpty) {

if (showLoader) {

toggleLoadingClass();

}

processResultData(getResults(q));

}

}

/**

* Toggles loading class on results and found string

* @return null

*/

function toggleLoadingClass() {

$resultsPlaceholder.toggleClass(loadingClass);

$foundContainer.toggleClass(loadingClass);

}

/**

* Process search result data

* @return null

*/

function processResultData(searchResults) {

$results = [];

// console.log('Search Results: ' + searchResults);

var resultsCount = 0,

results = '';

// Iterate over the results

searchResults.forEach(function(result) {

var loaded_data = JSON.parse(sessionStorage.getItem('actualData'));

var item = loaded_data[result.ref];

var result = populateResultContent($resultTemplate.html(), item);

resultsCount++;

results += result;

});

if (showLoader) {

toggleLoadingClass();

}

populateResultsString(resultsCount);

showSearchResults(results);

}

/**

* Add search results to placeholder

* @param {String} results

* @return null

*/

function showSearchResults(results) {

// Add results HTML to placeholder

$resultsPlaceholder.html(results);

}

/**

* Add results content to item template

* @param {String} html

* @param {object} item

* @return {String} Populated HTML

*/

function populateResultContent(html, item) {

html = injectContent(html, item.title, '##Title##');

html = injectContent(html, item.link, '##Url##');

if (item.excerpt) {

html = injectContent(html, item.excerpt, '##Excerpt##');

} else {

html = injectContent(html, '', '##Excerpt##');

}

if (item.date) {

html = injectContent(html, item.date, '##Date##');

} else {

html = injectContent(html, '', '##Date##');

}

return html;

}

/**

* Populates results string

* @param {String} count

* @return null

*/

function populateResultsString(count) {

if (typeof window.history.replaceState == 'function') {

history.replaceState({}, '', '?q='+encodeURIComponent(q));

}

$foundTerm.text(q);

$foundCount.text(count);

$foundContainer.show();

}

/* ==========================================================================

Helper functions

========================================================================== */

/**

* Gets query string parameter - taken from http://stackoverflow.com/questions/901115/how-can-i-get-query-string-values-in-javascript

* @param {String} name

* @return {String} parameter value

*/

function getParameterByName(name) {

var match = RegExp('[?&]' + name + '=([^&]*)').exec(window.location.search);

return match && decodeURIComponent(match[1].replace(/\+/g, ' '));

}

/**

* Injects content into template using placeholder

* @param {String} originalContent

* @param {String} injection

* @param {String} placeholder

* @return {String} injected content

*/

function injectContent(originalContent, injection, placeholder) {

var regex = new RegExp(placeholder, 'g');

return originalContent.replace(regex, injection);

}