dom-utils

function isNil(obj:any): boolean {
    return typeof obj === "undefined" || obj === null;
}


function fixCls(clsStr: string): string {
    if (!clsStr) {
        return "";
    }

    let clsArray = clsStr.split(" ");
    clsArray = clsArray.filter((cls) => {
        return cls.length > 0;
    });
    if (clsArray.length === 0) {
        return "";
    }

    clsArray = clsArray.map((cls) => {
        if (cls.startsWith("next")) {
            return cls;
        }
        return `SOME_PREFIX_${cls}`;
    })

    return clsArray.join(" ");
}

const html2EscapeEnums: Record<string, string> = {
    '<': '&lt;',
    '>': '&gt;',
    '&': '&amp;',
    '"': '&quot;'
};

function html2Escape(sHtml: string) {
    return sHtml.replace(/[<>&"]/g, function (c) {
        return html2EscapeEnums[c] || c;
    });
}

function appendChild(element: HTMLElement, child: any) {
    if (isNil(child)) {
        return;
    } else if (typeof child === "string") {
        const txt = html2Escape(child);
        const oTxt = document.createTextNode(txt);
        element.appendChild(oTxt);
        return;
    } else if (child instanceof HTMLElement) {
        element.appendChild(child);
        return;
    } else {
        const oTxt = document.createTextNode('' + child);
        element.appendChild(oTxt);
    }
}


function createElement(tagName: string, clazz: string, children?: any) {
    const element = document.createElement(tagName);
    element.className = fixCls(clazz);
    if (!isNil(children)) {
        if (Array.isArray(children)) {
            for (let i = 0; i < children.length; i++) {
                const child = children[i];
                appendChild(element, child);
            }
        } else {
            appendChild(element, children);
        }
    }
    return element;
}


function div(clazz: string, children?: any): HTMLElement {
    return createElement('div', clazz, children);
}

function span(clazz: string, children?: any): HTMLElement {
    return createElement('span', clazz, children);
}

function img(clazz: string, src: string): HTMLElement {
    const img = createElement('img', clazz);
    img.setAttribute('src', src);
    return img;
}

function ifElse(c: boolean, arr: HTMLElement[]): HTMLElement | null {
    const a = isNil(arr[0]) ? null : arr[0];
    const b = isNil(arr[1]) ? null : arr[1];
    return c ? a : b;
}

export {
    span,
    div,
    img,
    ifElse
}