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cryptpad/www/common/metadata-manager.js

221 lines
9.3 KiB
JavaScript

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define(['json.sortify'], function (Sortify) {
var UNINIT = 'uninitialized';
var create = function (sframeChan) {
var meta = UNINIT;
var members = [];
var metadataObj = UNINIT;
// This object reflects the metadata which is in the document at this moment.
// Normally when a person leaves the pad, everybody sees them leave and updates
// their metadata, this causes everyone to fight to change the document and
// operational transform doesn't like it. So this is a lazy object which is
// only updated either:
// 1. On changes to the metadata that come in from someone else
// 2. On changes connects, disconnects or changes to your own metadata
var metadataLazyObj = UNINIT;
var priv = {};
var dirty = true;
var changeHandlers = [];
var lazyChangeHandlers = [];
var titleChangeHandlers = [];
// When someone leaves the document, their metadata is removed from our metadataObj
// but it is not removed instantly from the chainpad document metadata. This is
// the result of the lazy object: if we had to remove the metadata instantly, all
// the remaining members would try to push a patch to do it, and it could create
// conflicts. Their metadata is instead removed from the chainpad doc only when
// someone calls onLocal to make another change.
// The leaving user is not visible in the userlist UI because we filter it using
// the list of "members" (netflux ID currently online).
// Our Problem:
// With the addition of shared workers, a user can leave and join back with the same
// netflux ID (just reload the pad). If nobody has made any change in the mean time,
// their metadata will still be in the document, but they won't be in our metadataObj.
// This causes the presence of a "viewer" instead of an editor, because they don't
// have user data.
// To fix this problem, the metadata manager can request "syncs" from a chainpad app,
// and the app should trigger a "metadataMgr.updateMetadata(data)" in the handler.
// See "metadataMgr.onRequestSync" in sframe-app-framework for an example.
var syncHandlers = [];
var rememberedTitle;
var checkUpdate = function (lazy) {
if (!dirty) { return; }
if (meta === UNINIT) { throw new Error(); }
if (metadataObj === UNINIT) {
metadataObj = {
defaultTitle: meta.doc.defaultTitle,
//title: meta.doc.defaultTitle,
type: meta.doc.type,
users: {},
authors: {}
};
metadataLazyObj = JSON.parse(JSON.stringify(metadataObj));
}
if (!metadataObj.users) { metadataObj.users = {}; }
if (!metadataLazyObj.users) { metadataLazyObj.users = {}; }
if (!metadataObj.type) { metadataObj.type = meta.doc.type; }
if (!metadataLazyObj.type) { metadataLazyObj.type = meta.doc.type; }
var mdo = {};
// We don't want to add our user data to the object multiple times.
Object.keys(metadataObj.users).forEach(function (x) {
if (members.indexOf(x) === -1) { return; }
mdo[x] = metadataObj.users[x];
});
if (!priv.readOnly) {
mdo[meta.user.netfluxId] = meta.user;
}
metadataObj.users = mdo;
// Always update the userlist in the lazy object, otherwise it may be outdated
// and metadataMgr.updateMetadata() won't do anything, and so we won't push events
// to the userlist UI ==> phantom viewers
var lazyUserStr = Sortify(metadataLazyObj.users[meta.user.netfluxId]);
dirty = false;
if (lazy || lazyUserStr !== Sortify(meta.user)) {
metadataLazyObj = JSON.parse(JSON.stringify(metadataObj));
lazyChangeHandlers.forEach(function (f) { f(); });
} else {
metadataLazyObj.users = JSON.parse(JSON.stringify(mdo));
}
if (metadataObj.title !== rememberedTitle) {
rememberedTitle = metadataObj.title;
titleChangeHandlers.forEach(function (f) {
f(metadataObj.title, metadataObj.defaultTitle);
});
}
changeHandlers.forEach(function (f) { f(); });
};
var change = function (lazy) {
dirty = true;
setTimeout(function () {
checkUpdate(lazy);
});
};
var addAuthor = function () {
if (!meta.user || !meta.user.netfluxId || !priv || !priv.edPublic) { return; }
var authors = metadataObj.authors || {};
if (!authors[priv.edPublic]) {
authors[priv.edPublic] = {
nId: [meta.user.netfluxId],
name: meta.user.name
};
} else {
authors[priv.edPublic].name = meta.user.name;
if (authors[priv.edPublic].nId.indexOf(meta.user.netfluxId) === -1) {
authors[priv.edPublic].nId.push(meta.user.netfluxId);
}
}
metadataObj.authors = authors;
metadataLazyObj.authors = JSON.parse(JSON.stringify(authors));
change();
};
var netfluxId;
var isReady = false;
var readyHandlers = [];
sframeChan.on('EV_METADATA_UPDATE', function (ev) {
meta = ev;
if (ev.priv) {
priv = ev.priv;
}
if (netfluxId) {
meta.user.netfluxId = netfluxId;
}
if (!isReady) {
isReady = true;
readyHandlers.forEach(function (f) { f(); });
}
change(true);
});
sframeChan.on('EV_RT_CONNECT', function (ev) {
netfluxId = ev.myID;
members = ev.members;
if (!meta.user) { return; }
meta.user.netfluxId = netfluxId;
change(true);
});
sframeChan.on('EV_RT_JOIN', function (ev) {
var idx = members.indexOf(ev);
if (idx !== -1) { console.log('Error: ' + ev + ' is already in members'); return; }
members.push(ev);
if (!meta.user) { return; }
change(false);
syncHandlers.forEach(function (f) { f(); });
});
sframeChan.on('EV_RT_LEAVE', function (ev) {
var idx = members.indexOf(ev);
if (idx === -1) { console.log('Error: ' + ev + ' not in members'); return; }
members.splice(idx, 1);
if (!meta.user) { return; }
change(false);
});
sframeChan.on('EV_RT_DISCONNECT', function () {
members = [];
if (!meta.user) { return; }
change(true);
});
sframeChan.on('EV_RT_ERROR', function (err) {
if (err.type !== 'EEXPIRED' && err.type !== 'EDELETED') { return; }
members = [];
if (!meta.user) { return; }
change(true);
});
return Object.freeze({
updateMetadata: function (m) {
// JSON.parse(JSON.stringify()) reorders the json, so we have to use sortify even
// if it's on our own computer
if (!m) { return; }
if (Sortify(metadataLazyObj) === Sortify(m)) { return; }
metadataObj = JSON.parse(JSON.stringify(m));
metadataLazyObj = JSON.parse(JSON.stringify(m));
change(false);
},
updateTitle: function (t) {
metadataObj.title = t;
change(true);
},
getMetadata: function () {
checkUpdate(false);
return Object.freeze(JSON.parse(JSON.stringify(metadataObj)));
},
getMetadataLazy: function () {
return metadataLazyObj;
},
onTitleChange: function (f) { titleChangeHandlers.push(f); },
onChange: function (f) { changeHandlers.push(f); },
onChangeLazy: function (f) { lazyChangeHandlers.push(f); },
onRequestSync: function (f) { syncHandlers.push(f); },
isConnected : function () {
return members.indexOf(meta.user.netfluxId) !== -1;
},
getViewers : function () {
checkUpdate(false);
var list = members.slice().filter(function (m) { return m.length === 32; });
return list.length - Object.keys(metadataLazyObj.users).length;
},
getChannelMembers: function () { return members.slice(); },
getPrivateData : function () {
return priv;
},
getUserData : function () {
return meta.user;
},
getNetfluxId : function () {
return meta.user.netfluxId;
},
onReady: function (f) {
if (isReady) { return void f(); }
readyHandlers.push(f);
},
addAuthor: addAuthor,
});
};
return Object.freeze({ create: create });
});