gecko-dev/dom/manifest/ImageObjectProcessor.sys.mjs

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6.5 KiB
JavaScript

/* 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
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
/*
* ImageObjectProcessor
* Implementation of Image Object processing algorithms from:
* http://www.w3.org/TR/appmanifest/#image-object-and-its-members
*
* This is intended to be used in conjunction with ManifestProcessor.jsm
*
* Creates an object to process Image Objects as defined by the
* W3C specification. This is used to process things like the
* icon member and the splash_screen member.
*
* Usage:
*
* .process(aManifest, aBaseURL, aMemberName);
*
*/
export function ImageObjectProcessor(aErrors, aExtractor, aBundle) {
this.errors = aErrors;
this.extractor = aExtractor;
this.domBundle = aBundle;
}
const iconPurposes = Object.freeze(["any", "maskable", "monochrome"]);
// Static getters
Object.defineProperties(ImageObjectProcessor, {
decimals: {
get() {
return /^\d+$/;
},
},
anyRegEx: {
get() {
return new RegExp("any", "i");
},
},
});
ImageObjectProcessor.prototype.process = function (
aManifest,
aBaseURL,
aMemberName
) {
const spec = {
objectName: "manifest",
object: aManifest,
property: aMemberName,
expectedType: "array",
trim: false,
};
const { domBundle, extractor, errors } = this;
const images = [];
const value = extractor.extractValue(spec);
if (Array.isArray(value)) {
value
.map(toImageObject)
// Filter out images that resulted in "failure", per spec.
.filter(image => image)
.forEach(image => images.push(image));
}
return images;
function toImageObject(aImageSpec, index) {
let img; // if "failure" happens below, we return undefined.
try {
// can throw
const src = processSrcMember(aImageSpec, aBaseURL, index);
// can throw
const purpose = processPurposeMember(aImageSpec, index);
const type = processTypeMember(aImageSpec);
const sizes = processSizesMember(aImageSpec);
img = {
src,
purpose,
type,
sizes,
};
} catch (err) {
/* Errors are collected by each process* function */
}
return img;
}
function processPurposeMember(aImage, index) {
const spec = {
objectName: "image",
object: aImage,
property: "purpose",
expectedType: "string",
trim: true,
throwTypeError: true,
};
// Type errors are treated at "any"...
let value;
try {
value = extractor.extractValue(spec);
} catch (err) {
return ["any"];
}
// Was only whitespace...
if (!value) {
return ["any"];
}
const keywords = value.split(/\s+/);
// Emtpy is treated as "any"...
if (keywords.length === 0) {
return ["any"];
}
// We iterate over keywords and classify them into:
const purposes = new Set();
const unknownPurposes = new Set();
const repeatedPurposes = new Set();
for (const keyword of keywords) {
const canonicalKeyword = keyword.toLowerCase();
if (purposes.has(canonicalKeyword)) {
repeatedPurposes.add(keyword);
continue;
}
iconPurposes.includes(canonicalKeyword)
? purposes.add(canonicalKeyword)
: unknownPurposes.add(keyword);
}
// Tell developer about unknown purposes...
if (unknownPurposes.size) {
const warn = domBundle.formatStringFromName(
"ManifestImageUnsupportedPurposes",
[aMemberName, index, [...unknownPurposes].join(" ")]
);
errors.push({ warn });
}
// Tell developer about repeated purposes...
if (repeatedPurposes.size) {
const warn = domBundle.formatStringFromName(
"ManifestImageRepeatedPurposes",
[aMemberName, index, [...repeatedPurposes].join(" ")]
);
errors.push({ warn });
}
if (purposes.size === 0) {
const warn = domBundle.formatStringFromName("ManifestImageUnusable", [
aMemberName,
index,
]);
errors.push({ warn });
throw new TypeError(warn);
}
return [...purposes];
}
function processTypeMember(aImage) {
const charset = {};
const hadCharset = {};
const spec = {
objectName: "image",
object: aImage,
property: "type",
expectedType: "string",
trim: true,
};
let value = extractor.extractValue(spec);
if (value) {
value = Services.io.parseRequestContentType(value, charset, hadCharset);
}
return value || undefined;
}
function processSrcMember(aImage, aBaseURL, index) {
const spec = {
objectName: aMemberName,
object: aImage,
property: "src",
expectedType: "string",
trim: false,
throwTypeError: true,
};
const value = extractor.extractValue(spec);
let url;
if (typeof value === "undefined" || value === "") {
// We throw here as the value is unusable,
// but it's not an developer error.
throw new TypeError();
}
if (value && value.length) {
try {
url = new URL(value, aBaseURL).href;
} catch (e) {
const warn = domBundle.formatStringFromName(
"ManifestImageURLIsInvalid",
[aMemberName, index, "src", value]
);
errors.push({ warn });
throw e;
}
}
return url;
}
function processSizesMember(aImage) {
const sizes = new Set();
const spec = {
objectName: "image",
object: aImage,
property: "sizes",
expectedType: "string",
trim: true,
};
const value = extractor.extractValue(spec);
if (value) {
// Split on whitespace and filter out invalid values.
value
.split(/\s+/)
.filter(isValidSizeValue)
.reduce((collector, size) => collector.add(size), sizes);
}
return sizes.size ? Array.from(sizes) : undefined;
// Implementation of HTML's link@size attribute checker.
function isValidSizeValue(aSize) {
const size = aSize.toLowerCase();
if (ImageObjectProcessor.anyRegEx.test(aSize)) {
return true;
}
if (!size.includes("x") || size.indexOf("x") !== size.lastIndexOf("x")) {
return false;
}
// Split left of x for width, after x for height.
const widthAndHeight = size.split("x");
const w = widthAndHeight.shift();
const h = widthAndHeight.join("x");
const validStarts = !w.startsWith("0") && !h.startsWith("0");
const validDecimals = ImageObjectProcessor.decimals.test(w + h);
return validStarts && validDecimals;
}
}
};