Function getRulesAsync

src/inject/dynamic-theme/style-manager.ts:258–324

()

    const loadingLinkId = ++loadingLinkCounter;

    async function getRulesAsync(): Promise<CSSRuleList | null> {
        let cssText: string;
        let cssBasePath: string;

        if (element instanceof HTMLLinkElement) {
            let [cssRules, accessError] = getRulesOrError();
            if (accessError) {
                logWarn(accessError);
            }

            if (
                (isSafari && !element.sheet) ||
                (!isSafari && !cssRules && !accessError) ||
                isStillLoadingError(accessError!)
            ) {
                try {
                    logInfo(`Linkelement ${loadingLinkId} is not loaded yet and thus will be await for`, element);
                    await linkLoading(element, loadingLinkId);
                } catch (err) {
                    // NOTE: Some @import resources can fail,
                    // but the style sheet can still be valid.
                    // There's no way to get the actual error.
                    logWarn(err);
                    wasLoadingError = true;
                }
                if (cancelAsyncOperations) {
                    return null;
                }

                [cssRules, accessError] = getRulesOrError();
                if (accessError) {
                    // CORS error, cssRules are not accessible
                    // for cross-origin resources
                    logWarn(accessError);
                }
            }

            if (cssRules) {
                if (!hasImports(cssRules, false)) {
                    return cssRules;
                }
            }

            try {
                cssText = await loadText(element.href);
            } catch (err) {
                logWarn(err);
                cssText = '';
            }
            cssBasePath = getCSSBaseBath(element.href);
            if (cancelAsyncOperations) {
                return null;
            }
        } else if (containsCSSImport()) {
            cssText = element.textContent!.trim();
            cssBasePath = getCSSBaseBath(location.href);
        } else {
            return null;