hugo-theme-relearn/static/js/lunr-adapter.js
2024-10-25 18:07:07 +02:00

136 lines
3.6 KiB
JavaScript

/*
# Adapter Interface
The search adapter needs to provide the following functions that are called from search.js
## init()
Initialize the search engine and the search index
### Parameters
none
### Returns
none
### Remarks
Once successfully completed, needs to call
````
window.relearn.isSearchEngineReady = true;
window.relearn.executeInitialSearch();
````
## search()
Performs the search and returs found results.
### Parameters
term: string // the search term that was typed in by the user
### Returns
Must return an array of found pages, sorted with the most relevant page first.
Each array item needs the following layout:
````
{
index: string, // optional, id of the page in the search index
matches: string[], // optional, TODO: have to find out what it does
page: {
breadcrumb: string,
title: string,
uri: string,
content: string,
tags: string[]
}
}
````
*/
let lunrIndex, pagesIndex;
function init() {
function initLunrIndex( index ){
pagesIndex = index;
// Set up Lunr by declaring the fields we use
// Also provide their boost level for the ranking
lunrIndex = lunr(function() {
this.use(lunr.multiLanguage.apply(null, contentLangs));
this.ref('index');
this.field('title', {
boost: 15
});
this.field('tags', {
boost: 10
});
this.field('content', {
boost: 5
});
this.pipeline.remove(lunr.stemmer);
this.searchPipeline.remove(lunr.stemmer);
// Feed Lunr with each file and let index them
pagesIndex.forEach(function(page, idx) {
page.index = idx;
this.add(page);
}, this);
});
window.relearn.isSearchEngineReady = true;
window.relearn.executeInitialSearch();
}
if( window.index_js_url ){
var js = document.createElement("script");
js.src = index_js_url;
js.setAttribute("async", "");
js.onload = function(){
initLunrIndex(relearn_searchindex);
};
js.onerror = function(e){
console.error('Error getting Hugo index file');
};
document.head.appendChild(js);
}
}
function search(term) {
function searchPatterns(word) {
// for short words high amounts of typos doesn't make sense
// for long words we allow less typos because this largly increases search time
var typos = [
{ len: -1, typos: 1 },
{ len: 60, typos: 2 },
{ len: 40, typos: 3 },
{ len: 20, typos: 4 },
{ len: 16, typos: 3 },
{ len: 12, typos: 2 },
{ len: 8, typos: 1 },
{ len: 4, typos: 0 },
];
return [
word + '^100',
word + '*^10',
'*' + word + '^10',
word + '~' + typos.reduce( function( a, c, i ){ return word.length < c.len ? c : a; } ).typos + '^1'
];
}
// Find the item in our index corresponding to the Lunr one to have more info
// Remove Lunr special search characters: https://lunrjs.com/guides/searching.html
term = term.replace( /[*:^~+-]/g, ' ' );
var searchTerm = lunr.tokenizer( term ).reduce( function(a,token){return a.concat(searchPatterns(token.str))}, []).join(' ');
return !searchTerm || !lunrIndex ? [] : lunrIndex.search(searchTerm).map(function(result) {
return { index: result.ref, matches: Object.keys(result.matchData.metadata), page: pagesIndex[ result.ref ] };
});
}
export { init, search };