wiki/assets/js/search.js

// code from https://github.com/danestves/markdown-to-text
const removeMarkdown = (
    markdown,
    options = {
        listUnicodeChar: false,
        stripListLeaders: true,
        gfm: true,
        useImgAltText: false,
        preserveLinks: false,
    }
) => {
    let output = markdown || "";
    output = output.replace(/^(-\s*?|\*\s*?|_\s*?){3,}\s*$/gm, "");

    try {
        if (options.stripListLeaders) {
            if (options.listUnicodeChar)
                output = output.replace(
                    /^([\s\t]*)([\*\-\+]|\d+\.)\s+/gm,
                    options.listUnicodeChar + " $1"
                );
            else output = output.replace(/^([\s\t]*)([\*\-\+]|\d+\.)\s+/gm, "$1");
        }
        if (options.gfm) {
            output = output
                .replace(/\n={2,}/g, "\n")
                .replace(/~{3}.*\n/g, "")
                .replace(/~~/g, "")
                .replace(/`{3}.*\n/g, "");
        }
        if (options.preserveLinks) {
            output = output.replace(/\[(.*?)\][\[\(](.*?)[\]\)]/g, "$1 ($2)")
        }
        output = output
            .replace(/<[^>]*>/g, "")
            .replace(/^[=\-]{2,}\s*$/g, "")
            .replace(/\[\^.+?\](\: .*?$)?/g, "")
            .replace(/\s{0,2}\[.*?\]: .*?$/g, "")
            .replace(/\!\[(.*?)\][\[\(].*?[\]\)]/g, options.useImgAltText ? "$1" : "")
            .replace(/\[(.*?)\][\[\(].*?[\]\)]/g, "$1")
            .replace(/^\s{0,3}>\s?/g, "")
            .replace(/(^|\n)\s{0,3}>\s?/g, "\n\n")
            .replace(/^\s{1,2}\[(.*?)\]: (\S+)( ".*?")?\s*$/g, "")
            .replace(
                /^(\n)?\s{0,}#{1,6}\s+| {0,}(\n)?\s{0,}#{0,} {0,}(\n)?\s{0,}$/gm,
                "$1$2$3"
            )
            .replace(/([\*_]{1,3})(\S.*?\S{0,1})\1/g, "$2")
            .replace(/([\*_]{1,3})(\S.*?\S{0,1})\1/g, "$2")
            .replace(/(`{3,})(.*?)\1/gm, "$2")
            .replace(/`(.+?)`/g, "$1")
            .replace(/\n{2,}/g, "\n\n");
    } catch (e) {
        console.error(e);
        return markdown;
    }
    return output;
};
// -----

(async function() {
    const contentIndex = new FlexSearch.Document({
    cache: true,
    charset: "latin:extra",
    optimize: true,
    worker: true,
    document: {
    index: [{
        field: "content",
        tokenize: "strict",
        context: {
        resolution: 5,
        depth: 3,
        bidirectional: true
        },
        suggest: true,
    }, {
        field: "title",
        tokenize: "forward",
    }]
    }
    })

    const { content } = await fetchData()
    for (const [key, value] of Object.entries(content)) {
    contentIndex.add({
    id: key,
    title: value.title,
    content: removeMarkdown(value.content),
    })
    }

    const highlight = (content, term) => {
    const highlightWindow = 20
    const tokenizedTerm = term.split(/\s+/).filter(t => t !== "")
    const splitText = content.split(/\s+/).filter(t => t !== "")
    const includesCheck = (token) => tokenizedTerm.some(term => token.toLowerCase().startsWith(term.toLowerCase()))

    const occurrencesIndices = splitText
    .map(includesCheck)

    // calculate best index
    let bestSum = 0
    let bestIndex = 0
    for (let i = 0; i < Math.max(occurrencesIndices.length - highlightWindow, 0); i++) {
    const window = occurrencesIndices.slice(i, i + highlightWindow)
    const windowSum = window.reduce((total, cur) => total + cur, 0)
    if (windowSum >= bestSum) {
        bestSum = windowSum
        bestIndex = i
    }
    }

    const startIndex = Math.max(bestIndex - highlightWindow, 0)
    const endIndex = Math.min(startIndex + 2 * highlightWindow, splitText.length)
    const mappedText = splitText
    .slice(startIndex, endIndex)
    .map(token => {
        if (includesCheck(token)) {
        return `<span class="search-highlight">${token}</span>`
        }
        return token
    })
    .join(" ")
    .replaceAll('</span> <span class="search-highlight">', " ")
    return `${startIndex === 0 ? "" : "..."}${mappedText}${endIndex === splitText.length ? "" : "..."}`
    }

    const resultToHTML = ({url, title, content, term}) => {
    const text = removeMarkdown(content)
    const resultTitle = highlight(title, term)
    const resultText = highlight(text, term)
    return `<button class="result-card" id="${url}">
        <h3>${resultTitle}</h3>
        <p>${resultText}</p>
    </button>`
    }

    const redir = (id, term) => {
    window.location.href = BASE_URL + `${id}#:~:text=${encodeURIComponent(term)}`
    }

    const formatForDisplay = id => ({
    id,
    url: id,
    title: content[id].title,
    content: content[id].content
    })

    const source = document.getElementById('search-bar')
    const results = document.getElementById("results-container")
    let term
    source.addEventListener("keyup", (e) => {
    if (e.key === "Enter") {
    const anchor = document.getElementsByClassName("result-card")[0]
    redir(anchor.id, term)
    }
    })
    source.addEventListener('input', (e) => {
    term = e.target.value
    contentIndex.search(term, [
    {
        field: "content",
        limit: 10,
        suggest: true,
    },
    {
        field: "title",
        limit: 5,
    }
    ]).then(searchResults => {
    const getByField = field => {
        const results = searchResults.filter(x => x.field === field)
        if (results.length === 0) {
        return []
        } else {
        return [...results[0].result]
        }
    }
    const allIds = new Set([...getByField('title'), ...getByField('content')])
    const finalResults = [...allIds].map(formatForDisplay)

    // display
    if (finalResults.length === 0) {
        results.innerHTML = `<button class="result-card">
                    <h3>No results.</h3>
                    <p>Try another search term?</p>
                </button>`
    } else {
        results.innerHTML = finalResults
        .map(result => resultToHTML({
            ...result,
            term,
        }))
        .join("\n")
        const anchors = document.getElementsByClassName("result-card");
        [...anchors].forEach(anchor => {
        anchor.onclick = () => redir(anchor.id, term)
        })
    }
    })
    })


    const searchContainer = document.getElementById("search-container")

    function openSearch() {
    if (searchContainer.style.display === "none" || searchContainer.style.display === "") {
    source.value = ""
    results.innerHTML = ""
    searchContainer.style.display = "block"
    source.focus()
    } else {
    searchContainer.style.display = "none"
    }
    }

    function closeSearch() {
    searchContainer.style.display = "none"
    }

    document.addEventListener('keydown', (event) => {
    if (event.key === "/") {
    event.preventDefault()
    openSearch()
    }
    if (event.key === "Escape") {
    event.preventDefault()
    closeSearch()
    }
    })

    const searchButton = document.getElementById("search-icon")
    searchButton.addEventListener('click', (evt) => {
    openSearch()
    })
    searchButton.addEventListener('keydown', (evt) => {
    openSearch()
    })
    searchContainer.addEventListener('click', (evt) => {
    closeSearch()
    })
    document.getElementById("search-space").addEventListener('click', (evt) => {
    evt.stopPropagation()
    })
})()