wekan/client/lib/unsavedEdits.js
2019-06-28 12:56:51 -05:00

76 lines
2.6 KiB
JavaScript

// `UnsavedEdits` is a global key-value store used to save drafts of user
// inputs. We used to have the notion of a `cachedValue` that was local to a
// component but the global store has multiple advantages:
// 1. When the component is unmounted (ie, destroyed) the draft isn't lost
// 2. The drafts are synced across multiple computers
// 3. The drafts are synced across multiple browser tabs
// XXX This currently doesn't work in purely offline mode since the sync is
// handled with the DDP connection to the server. To solve this, we could use
// something like GroundDB that syncs using localstorage.
//
// The key is a dictionary composed of two fields:
// * a `fieldName` which identifies the particular field. Since this is a global
// identifier a good practice would be to compose it with the collection name
// and the document field, eg. `boardTitle`, `cardDescription`.
// * a `docId` which identifies the appropriate document. In general we use
// MongoDB `_id` field.
//
// The value is a string containing the draft.
UnsavedEdits = {
// XXX Wanted to have the collection has an instance variable, but
// unfortunately the collection isn't defined yet at this point. We need ES6
// modules to solve the file order issue!
//
// _collection: UnsavedEditCollection,
get({ fieldName, docId }, defaultTo = '') {
const unsavedValue = this._getCollectionDocument(fieldName, docId);
if (unsavedValue) {
return unsavedValue.value;
} else {
return defaultTo;
}
},
has({ fieldName, docId }) {
return Boolean(this.get({ fieldName, docId }));
},
set({ fieldName, docId }, value) {
const currentDoc = this._getCollectionDocument(fieldName, docId);
if (currentDoc) {
UnsavedEditCollection.update(currentDoc._id, { $set: { value } });
} else {
UnsavedEditCollection.insert({
fieldName,
docId,
value,
});
}
},
reset({ fieldName, docId }) {
const currentDoc = this._getCollectionDocument(fieldName, docId);
if (currentDoc) {
UnsavedEditCollection.remove(currentDoc._id);
}
},
_getCollectionDocument(fieldName, docId) {
return UnsavedEditCollection.findOne({ fieldName, docId });
},
};
Blaze.registerHelper('getUnsavedValue', (fieldName, docId, defaultTo) => {
// Workaround some blaze feature that pass a list of keywords arguments as the
// last parameter (even if the caller didn't specify any).
if (!_.isString(defaultTo)) {
defaultTo = '';
}
return UnsavedEdits.get({ fieldName, docId }, defaultTo);
});
Blaze.registerHelper('hasUnsavedValue', (fieldName, docId) => {
return UnsavedEdits.has({ fieldName, docId });
});