ng-matero
Version:
Angular Material admin template
56 lines (42 loc) • 1.74 kB
text/typescript
import { SchematicsException, Tree } from '@angular-devkit/schematics';
import { Element, getChildElementIndentation } from '@angular/cdk/schematics';
import { parse as parseHtml } from 'parse5';
/** Appends the given element HTML fragment to the `<head>` element of the specified HTML file. */
export function appendHtmlElement(
host: Tree,
htmlFilePath: string,
elementHtml: string,
tag: string
) {
const htmlFileBuffer = host.read(htmlFilePath);
if (!htmlFileBuffer) {
throw new SchematicsException(`Could not read file for path: ${htmlFilePath}`);
}
const htmlContent = htmlFileBuffer.toString();
if (htmlContent.includes(elementHtml)) {
return;
}
const elemTag = getHtmlTagElement(htmlContent, tag);
if (!elemTag) {
throw new Error(`Could not find '<${tag}>' element in HTML file: ${htmlFileBuffer as any}`);
}
const endTagOffset = elemTag.sourceCodeLocation!.endTag!.startOffset;
const indentationOffset = getChildElementIndentation(elemTag);
const insertion = `${' '.repeat(indentationOffset)}${elementHtml}`;
const recordedChange = host.beginUpdate(htmlFilePath).insertRight(endTagOffset, `${insertion}\n`);
host.commitUpdate(recordedChange);
}
/** Parses the given HTML file and returns the element if available. */
export function getHtmlTagElement(htmlContent: string, tag: string): Element | null {
const document = parseHtml(htmlContent, { sourceCodeLocationInfo: true });
const nodeQueue = [...document.childNodes];
while (nodeQueue.length) {
const node = nodeQueue.shift() as Element;
if (node.nodeName.toLowerCase() === tag) {
return node;
} else if (node.childNodes) {
nodeQueue.push(...node.childNodes);
}
}
return null;
}