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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 gPrefs = {};
XPCOMUtils.defineLazyPreferenceGetter(
gPrefs,
"gEnabled",
"devtools.jsonview.enabled"
);
const JSON_VIEW_MIME_TYPE = "application/vnd.mozilla.json.view";
function getContentDisposition(channel) {
try {
return channel.contentDisposition;
} catch (e) {
// Channel doesn't support content dispositions
return null;
}
}
/**
* This component represents a sniffer (implements nsIContentSniffer
* interface) responsible for changing top level 'application/json'
* document types to: 'application/vnd.mozilla.json.view'.
*
* This internal type is consequently rendered by JSON View component
* that represents the JSON through a viewer interface.
*
* This is done in the .js file rather than a .jsm to avoid creating
* a compartment at startup when no JSON is being viewed.
*/
export class Sniffer {
getMIMETypeFromContent(request) {
if (request instanceof Ci.nsIChannel) {
// JSON View is enabled only for top level loads only.
if (
gPrefs.gEnabled &&
request.loadInfo?.isTopLevelLoad &&
request.loadFlags & Ci.nsIChannel.LOAD_DOCUMENT_URI &&
getContentDisposition(request) != Ci.nsIChannel.DISPOSITION_ATTACHMENT
) {
// Check the response content type and if it's a valid type
// such as application/json or application/manifest+json
// change it to new internal type consumed by JSON View.
if (/^application\/(?:.+\+)?json$/.test(request.contentType)) {
return JSON_VIEW_MIME_TYPE;
}
} else if (request.contentType === JSON_VIEW_MIME_TYPE) {
return "application/json";
}
}
return "";
}
}
Sniffer.prototype.QueryInterface = ChromeUtils.generateQI([
"nsIContentSniffer",
]);