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mirror of https://github.com/Jermolene/TiddlyWiki5 synced 2024-11-24 18:47:20 +00:00
TiddlyWiki5/plugins/tiddlywiki/browser-storage/startup.js
btheado 8a9d48e055
Allow browser storage plugin to delete existing tiddlers (#6625)
* Do not remove localstorage items while looping

While looping over all the browser storage items by index, the items
should not be removed because removing alters the index positions. The
item following the removed one will be skipped by the loop.

Instead, accumulate a list of keys to remove and remove them after the
loop.

* Implement full delete support for browser storage plugin

Before, deletes only worked for tiddlers which are only present in the
localstorage. Now deleted tiddlers are marked in localstorage using an
empty string value.

At startup, the localstorage tiddlers with empty strings will be deleted
from the wiki if they are still present. If they are already gone from
the wiki, then the blank localstorage entry will be deleted.

* Document drawbacks to using '[all[]]' and provide an alternative
2022-04-12 22:11:37 +01:00

130 lines
4.0 KiB
JavaScript

/*\
title: $:/plugins/tiddlywiki/browser-storage/startup.js
type: application/javascript
module-type: startup
Startup initialisation
\*/
(function(){
/*jslint node: true, browser: true */
/*global $tw: false */
"use strict";
// Export name and synchronous status
exports.name = "browser-storage";
exports.platforms = ["browser"];
exports.after = ["startup"];
exports.synchronous = true;
var ENABLED_TITLE = "$:/config/BrowserStorage/Enabled",
SAVE_FILTER_TITLE = "$:/config/BrowserStorage/SaveFilter",
QUOTA_EXCEEDED_ALERT_TITLE = "$:/config/BrowserStorage/QuotaExceededAlert",
DEFAULT_QUOTA_EXCEEDED_ALERT_PREFIX = "Quota exceeded attempting to store `",
DEFAULT_QUOTA_EXCEEDED_ALERT_SUFFIX = "` in browser local storage";
exports.startup = function() {
var self = this;
// Compute our prefix for local storage keys
var prefix = "tw5#" + window.location.pathname + "#";
// Make a logger
var logger = new $tw.utils.Logger("browser-storage",{
colour: "cyan"
});
// Function to compile the filter
var filterFn,
compileFilter = function() {
filterFn = $tw.wiki.compileFilter($tw.wiki.getTiddlerText(SAVE_FILTER_TITLE));
}
compileFilter();
// Listen for tm-clear-browser-storage messages
$tw.rootWidget.addEventListener("tm-clear-browser-storage",function(event) {
$tw.wiki.addTiddler({title: ENABLED_TITLE, text: "no"});
clearLocalStorage();
});
// Track tiddler changes
$tw.wiki.addEventListener("change",function(changes) {
// Bail if browser storage is disabled
if($tw.wiki.getTiddlerText(ENABLED_TITLE) === "no") {
return;
}
// Recompile the filter if it has changed
if(changes[SAVE_FILTER_TITLE]) {
compileFilter();
}
// Filter the changes
var filteredChanges = filterFn.call($tw.wiki,function(iterator) {
$tw.utils.each(changes,function(change,title) {
var tiddler = $tw.wiki.getTiddler(title);
iterator(tiddler,title);
});
});
$tw.utils.each(filteredChanges,function(title) {
// Don't try to save changes to our enabled status
// (If it were enabled in the file but disabled in local storage then we might not realise that distributing a copy of the file would have local storage enabled for other users)
if(title === ENABLED_TITLE) {
return;
}
// Save the tiddler
saveTiddlerToLocalStorage(title,{
logger: logger,
prefix: prefix
});
});
});
};
function saveTiddlerToLocalStorage(title,options) {
options = options || {};
// Get the tiddler
var tiddler = $tw.wiki.getTiddler(title);
if(tiddler) {
console.log("browser-storage: Saving",title);
// Get the JSON of the tiddler
var json = JSON.stringify(tiddler.getFieldStrings());
// Try to save it to local storage
try {
window.localStorage.setItem(options.prefix + title,json);
} catch(e) {
if(e.name === "QuotaExceededError") {
// Complain if we failed
var msg = $tw.wiki.getTiddlerText(QUOTA_EXCEEDED_ALERT_TITLE,DEFAULT_QUOTA_EXCEEDED_ALERT_PREFIX + title + DEFAULT_QUOTA_EXCEEDED_ALERT_SUFFIX);
if(options.logger) {
options.logger.alert(msg);
}
// No point in keeping old values around for this tiddler
window.localStorage.removeItem(options.prefix + title);
} else {
console.log("Browser-storage error:",e);
}
}
} else {
// In local storage, use the special value of empty string to mark the tiddler as deleted
// On future page loads, if the tiddler is already gone from startup then the blank entry
// will be removed from localstorage. Otherwise, the tiddler will be deleted.
console.log("browser-storage: Blanking",title);
try {
window.localStorage.setItem(options.prefix + title, "");
} catch(e) {
console.log("Browser-storage error:",e);
}
}
}
function clearLocalStorage() {
var url = window.location.pathname,
log = [];
// Step through each browsder storage item
for(var index=window.localStorage.length - 1; index>=0; index--) {
var key = window.localStorage.key(index),
parts = key.split("#");
// Delete it if it's ours
if(parts[0] === "tw5" && parts[1] === url) {
window.localStorage.removeItem(key);
}
}
}
})();