stylus/install.js

/*jshint undef:false*/
chrome.runtime.sendMessage({
    method: "getStyles",
    url: getMeta("stylish-id-url") || location.href
}, function (response) {
    if (response.length === 0) {
        sendEvent("styleCanBeInstalledChrome");
    } else {
        var installedStyle = response[0];
        // maybe an update is needed
        // use the md5 if available
        var md5Url = getMeta("stylish-md5-url");
        if (md5Url && installedStyle.md5Url && installedStyle.originalMd5) {
            getResource(md5Url, function (md5) {
                if (md5 == installedStyle.originalMd5) {
                    sendEvent("styleAlreadyInstalledChrome", {
                        updateUrl: installedStyle.updateUrl
                    });
                } else {
                    sendEvent("styleCanBeUpdatedChrome", {
                        updateUrl: installedStyle.updateUrl
                    });
                }
            });
        } else {
            getResource(getMeta("stylish-code-chrome"), function (code) {
                // this would indicate a failure (a style with settings?).
                if (code === null) {
                    sendEvent("styleCanBeUpdatedChrome", {
                        updateUrl: installedStyle.updateUrl
                    });
                }
                var json = JSON.parse(code);
                if (json.sections.length == installedStyle.sections.length) {
                    if (json.sections.every(function (section) {
                            return installedStyle.sections.some(function (installedSection) {
                                return sectionsAreEqual(section, installedSection);
                            });
                        })) {
                        // everything's the same
                        sendEvent("styleAlreadyInstalledChrome", {
                            updateUrl: installedStyle.updateUrl
                        });
                        return;
                    }
                }
                sendEvent("styleCanBeUpdatedChrome", {
                    updateUrl: installedStyle.updateUrl
                });
            });
        }
    }
});

function sectionsAreEqual(a, b) {
    if (a.code != b.code) {
        return false;
    }
    return ["urls", "urlPrefixes", "domains", "regexps"].every(function (attribute) {
        return arraysAreEqual(a[attribute], b[attribute]);
    });
}

function arraysAreEqual(a, b) {
    // treat empty array and undefined as equivalent
    if (typeof a == "undefined")
        return (typeof b == "undefined") || (b.length === 0);
    if (typeof b == "undefined")
        return (typeof a == "undefined") || (a.length === 0);
    if (a.length != b.length) {
        return false;
    }
    return a.every(function (entry) {
        return b.indexOf(entry) != -1;
    });
}

function sendEvent(type, data) {
    if (typeof data == "undefined") {
        data = null;
    }
    var stylishEvent = new CustomEvent(type, {
        detail: data
    });
    document.dispatchEvent(stylishEvent);
}

document.addEventListener("stylishInstallChrome", function () {
    getResource(getMeta("stylish-description"), function (name) {
        if (confirm(chrome.i18n.getMessage('styleInstall', [name]))) {
            getResource(getMeta("stylish-code-chrome"), function (code) {
                // check for old style json
                var json = JSON.parse(code);
                json.method = "saveStyle";
                chrome.runtime.sendMessage(json, function (response) {
                    sendEvent("styleInstalledChrome");
                });
            });
            getResource(getMeta("stylish-install-ping-url-chrome"));
        }
    });
}, false);

document.addEventListener("stylishUpdateChrome", function () {
    chrome.runtime.sendMessage({
        method: "getStyles",
        url: getMeta("stylish-id-url") || location.href
    }, function (response) {
        var style = response[0];
        if (confirm(chrome.i18n.getMessage('styleUpdate', [style.name]))) {
            getResource(getMeta("stylish-code-chrome"), function (code) {
                var json = JSON.parse(code);
                json.method = "saveStyle";
                json.id = style.id;
                chrome.runtime.sendMessage(json, function () {
                    sendEvent("styleInstalledChrome");
                });
            });
        }
    });
}, false);


function getMeta(name) {
    var e = document.querySelector("link[rel='" + name + "']");
    return e ? e.getAttribute("href") : null;
}

function getResource(url, callback) {
    if (url.indexOf("#") === 0) {
        if (callback) {
            callback(document.getElementById(url.substring(1)).innerText);
        }
        return;
    }
    var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function () {
        if (xhr.readyState == 4 && callback) {
            if (xhr.status >= 400) {
                callback(null);
            } else {
                callback(xhr.responseText);
            }
        }
    };
    if (url.length > 2000) {
        var parts = url.split("?");
        xhr.open("POST", parts[0], true);
        xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        xhr.send(parts[1]);
    } else {
        xhr.open("GET", url, true);
        xhr.send();
    }
}