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| /**
* Escape HTML tags as HTML entities
* Edited from:
* @link https://stackoverflow.com/a/5499821
*/
const tagsToReplace = {
'&': '&',
'<': '<',
'>': '>',
'"': '"',
'…': '…'
};
function replaceTag(tag) {
return tagsToReplace[tag] || tag;
}
function replaceHTMLEnt(str) {
return str.replace(/[&<>"]/g, replaceTag);
}
function escapeRegExp(string) {
return string.replace(/[.*+\-?^${}()|[\]\\]/g, '\\$&');
}
function Search({ form, input, list, resultTitle, resultTitleTemplate }) {
this.form = form;
this.input = input;
this.list = list;
this.resultTitle = resultTitle;
this.resultTitleTemplate = resultTitleTemplate;
this.data = null; // 用于缓存获取的数据
this.handleQueryString();
this.bindQueryStringChange();
this.bindSearchForm();
}
/**
* Processes search matches
* @param str original text
* @param matches array of matches
* @param ellipsis whether to add ellipsis to the end of each match
* @param charLimit max length of preview string
* @param offset how many characters before and after the match to include in preview
* @returns preview string
*/
Search.processMatches = function (str, matches, ellipsis = true, charLimit = 140, offset = 20) {
matches.sort((a, b) => {
return a.start - b.start;
});
let i = 0, lastIndex = 0, charCount = 0;
const resultArray = [];
while (i < matches.length) {
const item = matches[i];
if (ellipsis && item.start - offset > lastIndex) {
resultArray.push(`${replaceHTMLEnt(str.substring(lastIndex, lastIndex + offset))} [...] `);
resultArray.push(`${replaceHTMLEnt(str.substring(item.start - offset, item.start))}`);
charCount += offset * 2;
} else {
resultArray.push(replaceHTMLEnt(str.substring(lastIndex, item.start)));
charCount += item.start - lastIndex;
}
let j = i + 1, end = item.end;
while (j < matches.length && matches[j].start <= end) {
end = Math.max(matches[j].end, end);
++j;
}
resultArray.push(`<mark>${replaceHTMLEnt(str.substring(item.start, end))}</mark>`);
charCount += end - item.start;
i = j;
lastIndex = end;
if (ellipsis && charCount > charLimit) break;
}
if (lastIndex < str.length) {
let end = str.length;
if (ellipsis) end = Math.min(end, lastIndex + offset);
resultArray.push(`${replaceHTMLEnt(str.substring(lastIndex, end))}`);
if (ellipsis && end !== str.length) {
resultArray.push(` [...]`);
}
}
return resultArray.join('');
};
Search.prototype.searchKeywords = async function (keywords) {
const rawData = await this.getData();
const results = [];
const regex = new RegExp(keywords.filter((v, index, arr) => {
arr[index] = escapeRegExp(v);
return v.trim() !== '';
}).join('|'), 'gi');
for (const item of rawData) {
const titleMatches = [], contentMatches = [];
let result = Object.assign({}, item, { preview: '', matchCount: 0 });
const contentMatchAll = item.content.matchAll(regex);
for (const match of Array.from(contentMatchAll)) {
contentMatches.push({
start: match.index,
end: match.index + match[0].length
});
}
const titleMatchAll = item.title.matchAll(regex);
for (const match of Array.from(titleMatchAll)) {
titleMatches.push({
start: match.index,
end: match.index + match[0].length
});
}
if (titleMatches.length > 0) {
result.title = Search.processMatches(result.title, titleMatches, false);
}
if (contentMatches.length > 0) {
result.preview = Search.processMatches(result.content, contentMatches);
} else {
result.preview = replaceHTMLEnt(result.content.substring(0, 140));
}
result.matchCount = titleMatches.length + contentMatches.length;
if (result.matchCount > 0) results.push(result);
}
return results.sort((a, b) => b.matchCount - a.matchCount);
};
Search.prototype.doSearch = async function (keywords) {
const startTime = performance.now();
const results = await this.searchKeywords(keywords);
this.clear();
for (const item of results) {
this.list.appendChild(Search.render(item));
}
const endTime = performance.now();
this.resultTitle.innerText = this.generateResultTitle(results.length, ((endTime - startTime) / 1000).toPrecision(1));
};
Search.prototype.generateResultTitle = function (resultLen, time) {
return this.resultTitleTemplate.replace("#PAGES_COUNT", resultLen).replace("#TIME_SECONDS", time);
};
Search.prototype.getData = async function () {
if (!this.data) {
const jsonURL = this.form.dataset.json;
this.data = await fetch(jsonURL).then(res => res.json());
const parser = new DOMParser();
for (const item of this.data) {
item.content = parser.parseFromString(item.content, 'text/html').body.innerText;
}
}
return this.data;
};
Search.prototype.bindSearchForm = function () {
let lastSearch = '';
const eventHandler = (e) => {
e.preventDefault();
const keywords = this.input.value.trim();
Search.updateQueryString(keywords, true);
if (keywords === '') {
lastSearch = '';
return this.clear();
}
if (lastSearch === keywords) return;
lastSearch = keywords;
this.doSearch(keywords.split(' '));
};
this.input.addEventListener('input', eventHandler);
this.input.addEventListener('compositionend', eventHandler);
};
Search.prototype.clear = function () {
this.list.innerHTML = '';
this.resultTitle.innerText = '';
};
Search.prototype.bindQueryStringChange = function () {
window.addEventListener('popstate', () => {
this.handleQueryString();
});
};
Search.prototype.handleQueryString = function () {
const pageURL = new URL(window.location.toString());
const keywords = pageURL.searchParams.get('keyword');
this.input.value = keywords;
if (keywords) {
this.doSearch(keywords.split(' '));
} else {
this.clear();
}
};
Search.updateQueryString = function (keywords, replaceState = false) {
const pageURL = new URL(window.location.toString());
if (keywords === '') {
pageURL.searchParams.delete('keyword');
} else {
pageURL.searchParams.set('keyword', keywords);
}
if (replaceState) {
window.history.replaceState('', '', pageURL.toString());
} else {
window.history.pushState('', '', pageURL.toString());
}
};
Search.render = function (item) {
const article = document.createElement("article");
const link = document.createElement("a");
link.href = item.permalink;
const detailsDiv = document.createElement("div");
detailsDiv.className = "article-details";
const title = document.createElement("h2");
title.className = "article-title";
title.innerHTML = item.title;
detailsDiv.appendChild(title);
const preview = document.createElement("section");
preview.className = "article-preview";
preview.innerHTML = item.preview;
detailsDiv.appendChild(preview);
link.appendChild(detailsDiv);
article.appendChild(link);
return article;
};
window.addEventListener('load', () => {
setTimeout(() => {
const searchForm = document.querySelector('.search-form');
const searchInput = searchForm.querySelector('input');
const searchResultList = document.querySelector('.search-result--list');
const searchResultTitle = document.querySelector('.search-result--title');
new Search({
form: searchForm,
input: searchInput,
list: searchResultList,
resultTitle: searchResultTitle,
resultTitleTemplate: window.searchResultTitleTemplate
});
}, 0);
});
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