anki-md-template/模板-支持数学公式/正面内容模版.html

<div class="markdown-body">
    {{Front}}
</div>


<script>

    // 日志级别： debug、info、warn、error、off
    var config_logLevel = "error";

    // 是否展示数学公式转换错误信息
    var config_showMathError = false;


    // javascript 资源加载
    initScriptResource([
        "https://gcore.jsdelivr.net/npm/markdown-it@14.1.0/dist/markdown-it.min.js",
        "https://gcore.jsdelivr.net/gh/highlightjs/cdn-release@11.11.1/build/highlight.min.js",
        "https://gcore.jsdelivr.net/npm/markdown-it-texmath@1.0.0/texmath.min.js",
        "https://gcore.jsdelivr.net/npm/katex@0.16.22/dist/katex.min.js"
    ]).then(() => {
        // Anki 代码都执行完成后再执行，优先使用 Anki 自带的数学公式解析
        setTimeout(() => {
            try {
                parseMarkDownFn();
            } catch (e) {
                DivLog.error("Error: " + e);
            }
        });
    })


    /**
     * 转换卡片内容为 markdown 网页格式
     */
    function parseMarkDownFn() {
        // markdown-it 实例
        let md = markdownit({
            html: true,
            linkify: true,
            typographer: true,
            breaks: true,
            highlight: function (str, lang) {
                if (lang && hljs.getLanguage(lang)) {
                    try {
                        return hljs.highlight(str, {language: lang}).value
                    } catch (__) {
                    }
                }
                return '';
            }
        }).use(window.texmath, {
            engine: katex,
            // 设置数学公式标识符为：$...$ or $$...$$ or \(...\) or \[...\]
            // 参考：https://www.npmjs.com/package/markdown-it-texmath
            delimiters: ['dollars', 'brackets'],
            // 参考：https://katex.org/docs/options
            katexOptions: {
                output: 'html',
                throwOnError: false,
                // IOS 端没有 console.warn 方法
                strict: (errorCode, errorMsg, token) => {
                    if (config_showMathError) {
                        DivLog.error('Warn: ' + errorCode + ' ' + errorMsg + ' ' + token);
                        return "error";
                    } else {
                        DivLog.warn('Warn: ' + errorCode + ' ' + errorMsg + ' ' + token);
                        return "ignore";
                    }
                }
            }
        });
        // 转换内容
        document.querySelectorAll('.markdown-body').forEach((div, index) => {
            // 预处理文本，替换特殊字符，如：&lt; &gt; &amp; &nbsp;
            let text = preProcessText(div, index)
            // 转换成 markdown 网页格式
            text = md.render(text);
            DivLog.debug("After markdown-it conversion：", text);
            div.innerHTML = md.render(text);
        });
        // 最后将卡片显示，避免公式闪烁更新
        document.querySelectorAll('.markdown-body').forEach((div) => {
            div.style.opacity = 1;
        });
    }

    /**
     * 预处理文本，替换特殊字符
     * @param {Element} div
     * @param {number} index
     * @returns {string}
     */
    function preProcessText(div, index) {
        DivLog.debug("------------.markdown-body: " + (index + 1) + "------------");
        DivLog.debug("Original content：", div.innerHTML);
        let text = div.innerHTML

        // <code></code> 包裹的内容不做处理
        let code_tag_matches
        [text, code_tag_matches] = Censor.censorCodeHtml(text);
        if (code_tag_matches.length > 0) {
            DivLog.debug("After replacing <code></code>：", text);
        }

        text = text.trim()
            .replace(/&lt;/g, "<").replace(/&gt;/g, ">").replace(/&amp;/g, "&")
            .replace(/&nbsp;/g, ' ')
            .replace(/<br>/g, '\r\n');

        text = Censor.decensorCodeHtml(text, code_tag_matches)
        DivLog.debug("After replacing special characters：", text);
        return text;
    }

    /**
     * 加载 javascript 资源
     * @param scriptUrls 多个资源地址数组
     * @returns {Promise<Awaited<unknown>[]>|Promise<void>}
     */
    function initScriptResource(scriptUrls) {
        initMyClass();

        // 添加判断，避免重复加载
        if (typeof markdownit !== 'undefined') {
            DivLog.info("markdown-it is loaded!")
            return Promise.resolve();
        }

        DivLog.info("markdown-it did not load, re-adding triggers loading!")
        return Promise.all(scriptUrls.map(url => {
            return new Promise((resolve, reject) => {
                const script = document.createElement("script");
                script.onload = resolve;
                script.onerror = () => reject(new Error(`Failed to load script from ${url}`));
                script.src = url;
                document.head.appendChild(script);
            });
        })).catch(error => {
            DivLog.error('Error: ' + error);
            throw error;
        });
    }


    function initMyClass() {
        if (typeof DivLog === 'undefined') {
            window.DivLog = {
                LOG_LEVEL: "info",
                levelMap: {'debug': 5, 'info': 4, 'warn': 3, 'error': 2, 'off': 1},

                debug(...messages) {
                    if (this.levelMap[this.LOG_LEVEL] >= 5) {
                        this._log("", ...messages);
                    }
                },
                info(...messages) {
                    if (this.levelMap[this.LOG_LEVEL] >= 4) {
                        this._log("", ...messages);
                    }
                },
                warn(...messages) {
                    if (this.levelMap[this.LOG_LEVEL] >= 3) {
                        this._log("orange", ...messages);
                    }
                },
                error(...messages) {
                    if (this.levelMap[this.LOG_LEVEL] >= 2) {
                        this._log("red", ...messages);
                    }
                },
                _log(fontColor, ...messages) {
                    const messageDiv = document.createElement("div");
                    messageDiv.className = "my-message-div";
                    messageDiv.style.color = fontColor;
                    messages.forEach(message => {
                        messageDiv.appendChild(document.createTextNode(message));
                        messageDiv.appendChild(document.createElement("br"));
                    });
                    messageDiv.appendChild(document.createElement("hr"));
                    document.body.appendChild(messageDiv)
                },
                clearLogDiv() {
                    document.querySelectorAll(".my-message-div").forEach(div => div.remove());
                }
            };
            DivLog.LOG_LEVEL = config_logLevel;
        }
        DivLog.clearLogDiv();

        if (typeof Censor === 'undefined') {
            const ANKI_CODE_REGEXP = /<code[^>]*>([\s\S]*?)<\/code>/g;
            const ANKI_CODE_REPLACE = "##ANKI_CODE_REPLACE##";
            window.Censor = {
                censorCodeHtml: function (note_text) {
                    return this._censor(note_text, ANKI_CODE_REGEXP, ANKI_CODE_REPLACE)
                },
                decensorCodeHtml: function (note_text, replacements) {
                    return this._decensor(note_text, ANKI_CODE_REPLACE, replacements)
                },
                _censor: function (note_text, regexp, mask) {
                    /*Take note_text and replace every match of regexp with mask, simultaneously adding it to a string array*/
                    let matches = []
                    for (let match of note_text.matchAll(regexp)) {
                        matches.push(match[0])
                    }
                    return [note_text.replace(regexp, mask), matches]
                },
                _decensor: function (note_text, mask, replacements) {
                    for (let replacement of replacements) {
                        note_text = note_text.replace(mask, replacement)
                    }
                    return note_text
                }
            }
        }
    }


</script>