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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
JsonSchemaValidator:
});
ChromeUtils.defineLazyGetter(lazy, "logConsole", function () {
return console.createInstance({
prefix: "PageData",
maxLogLevel: Services.prefs.getBoolPref("browser.pagedata.log", false)
? "Debug"
: "Warn",
});
});
/**
* The list of page data collectors. These should be sorted in order of
* specificity, if the same piece of data is provided by two collectors then the
* earlier wins.
*
* Collectors must provide a `collect` function which will be passed the
* document object and should return the PageData structure. The function may be
* asynchronous if needed.
*
* The data returned need not be valid, collectors should return whatever they
* can and then we drop anything that is invalid once all data is joined.
*/
ChromeUtils.defineLazyGetter(lazy, "DATA_COLLECTORS", function () {
return [lazy.SchemaOrgPageData, lazy.OpenGraphPageData, lazy.TwitterPageData];
});
let SCHEMAS = new Map();
/**
* Loads the schema for the given name.
*
* @param {string} schemaName
* The name of the schema to load.
*/
async function loadSchema(schemaName) {
if (SCHEMAS.has(schemaName)) {
return SCHEMAS.get(schemaName);
}
let url = `chrome://browser/content/pagedata/schemas/${schemaName.toLocaleLowerCase()}.schema.json`;
let response = await fetch(url);
if (!response.ok) {
throw new Error(`Failed to load schema: ${response.statusText}`);
}
let schema = await response.json();
SCHEMAS.set(schemaName, schema);
return schema;
}
/**
* Validates the data using the schema with the given name.
*
* @param {string} schemaName
* The name of the schema to validate against.
* @param {object} data
* The data to validate.
*/
async function validateData(schemaName, data) {
let schema = await loadSchema(schemaName.toLocaleLowerCase());
let result = lazy.JsonSchemaValidator.validate(data, schema, {
allowExplicitUndefinedProperties: true,
// Allowed for future expansion of the schema.
allowAdditionalProperties: true,
});
if (!result.valid) {
throw result.error;
}
}
/**
* A shared API that can be used in parent or child processes
*/
export const PageDataSchema = {
// Enumeration of data types. The keys must match the schema name.
DATA_TYPE: Object.freeze({
// Note that 1 and 2 were used as types in earlier versions and should not be used here.
PRODUCT: 3,
DOCUMENT: 4,
ARTICLE: 5,
AUDIO: 6,
VIDEO: 7,
}),
/**
* Gets the data type name.
*
* @param {DATA_TYPE} type
* The data type from the DATA_TYPE enumeration
*
* @returns {string | null} The name for the type or null if not found.
*/
nameForType(type) {
for (let [name, value] of Object.entries(this.DATA_TYPE)) {
if (value == type) {
return name;
}
}
return null;
},
/**
* Asynchronously validates some page data against the expected schema. Throws
* an exception if validation fails.
*
* @param {DATA_TYPE} type
* The data type from the DATA_TYPE enumeration
* @param {object} data
* The page data
*/
async validateData(type, data) {
let name = this.nameForType(type);
if (!name) {
throw new Error(`Unknown data type ${type}`);
}
return validateData(name, data);
},
/**
* Asynchronously validates an entire PageData structure. Any invalid or
* unknown data types are dropped.
*
* @param {PageData} pageData
* The page data
*
* @returns {PageData} The validated page data structure
*/
async validatePageData(pageData) {
let { data: dataMap = {}, ...general } = pageData;
await validateData("general", general);
let validData = {};
for (let [type, data] of Object.entries(dataMap)) {
let name = this.nameForType(type);
// Ignore unknown types here.
if (!name) {
continue;
}
try {
await validateData(name, data);
validData[type] = data;
} catch (e) {
// Invalid data is dropped.
}
}
return {
...general,
data: validData,
};
},
/**
* Adds new page data into an existing data set. Any existing data is not
* overwritten.
*
* @param {PageData} existingPageData
* The existing page data
* @param {PageData} newPageData
* The new page data
*
* @returns {PageData} The joined data.
*/
coalescePageData(existingPageData, newPageData) {
// Split out the general data from the map of specific data.
let { data: existingMap = {}, ...existingGeneral } = existingPageData;
let { data: newMap = {}, ...newGeneral } = newPageData;
Object.assign(newGeneral, existingGeneral);
let dataMap = {};
for (let [type, data] of Object.entries(existingMap)) {
if (type in newMap) {
dataMap[type] = Object.assign({}, newMap[type], data);
} else {
dataMap[type] = data;
}
}
for (let [type, data] of Object.entries(newMap)) {
if (!(type in dataMap)) {
dataMap[type] = data;
}
}
return {
...newGeneral,
data: dataMap,
};
},
/**
* Collects page data from a DOM document.
*
* @param {Document} document
* The DOM document to collect data from
*
* @returns {Promise<PageData | null>} The data collected or null in case of
* error.
*/
async collectPageData(document) {
lazy.logConsole.debug("Starting collection", document.documentURI);
let pending = lazy.DATA_COLLECTORS.map(async collector => {
try {
return await collector.collect(document);
} catch (e) {
lazy.logConsole.error("Error collecting page data", e);
return null;
}
});
let pageDataList = await Promise.all(pending);
let pageData = pageDataList.reduce(PageDataSchema.coalescePageData, {
date: Date.now(),
url: document.documentURI,
});
try {
return this.validatePageData(pageData);
} catch (e) {
lazy.logConsole.error("Failed to collect valid page data", e);
return null;
}
},
};