Is there a way to temporarily (and programmatically) block interaction event handling in a vis.js network? (that is, clicks, roll overs, etc.). I would like to do this to avoid nasty interaction with other code that implements a 'time lapse' feature (that is, it essentially displays different parts of the network at consecutive, set intervals). In other words, I'd like to know whether I can prevent vis.js from drawing in response to events not originated by my script, while the script is executing. I noticed there's a 'clickToUse' feature, but it would not work well in this case because I need the script itself to determine when to stop blocking the event handling.
Any suggestions will be appreciated. Thanks!
You need manipulate interaction options. For example:
// Save interaction options to saveOpt variable
//
var saveOpt = {
interaction: JSON.parse( JSON.stringify( network.interactionHandler.options ) )
};
// Set all interaction options to false:
//
var newOpt = { interaction: {} };
Object.keys( saveOpt.interaction ).forEach( function(k) {
// Except number
if (typeof saveOpt.interaction[k] !== 'number') {
newOpt.interaction[k] = false;
}
});
// Prevent any interactions
//
network.setOptions( newOpt );
// Allow interactions (restore saved)
//
network.setOptions( saveOpt );
Related
I'm using ngrx/component-store and loving it so far. Having prior store knowledge building my own simple ones, the only real headache I've had so far is when I've had to update an array and figured out I have to always create a new one for the internal compare() pipe to realize the array got updated.
Anyway, reading through the documentation it talks about updater methods and patchState. To me they do exactly the same thing, but their creation is slightly different. You would call patchState inside of a method while this.updater() returns a method giving you a function you can expose in your service. Anytime I'm updating my state it's always after a network call. I assume there are plenty of scenarios where you'd want to update your state without a network call so this is why you would want to have an updater available to your component to call. The question is if an updater and patchState are really doing the same thing then is it a better practice to call an updater in an effect or use patchState, or maybe am I putting too much logic in my effect?
On a side note, the docs say an updater method is supposed to be a pure function. If you're using it to your push an object onto an array then is it really pure?
// adding the selectors so people know what components are subscribing to
readonly approvals$ = this.select(state => state.requestApprovals);
readonly registration$ = this.select(state => state);
readonly updateAssessment = this.effect(($judgement: Observable<{id: string, isApproved: boolean}>) => {
return $judgement.pipe(
switchMap((evaluation) => {
const state = this.get();
return this.requestApproval.patch(state.id, state.companyName, evaluation.id, evaluation.isApproved).pipe(
tapResponse(
(result) => {
// is it better to call patchState()?
this.patchState((state) => {
for(let i = 0; i < state.requestApprovals.length; i++) {
if(state.requestApprovals[i].id == result.id) {
state.requestApprovals[i].isApproved = result.isApproved;
}
}
// the take away is you must assign a whole new array object when you update it.
state.requestApprovals = Object.assign([], state.requestApprovals);
return state;
});
// or this updater?
// this.applyDecisionPatch(evaluation);
},
// oh look! another updater reassigning my array to the state so
// it propagates to subscribers to reset the UI
() => { this.reverseDecision(); }
)
);
})
);
});
// this is private to make sure this can only be called after a network request
private readonly applyDecisionPatch = this.updater((state, value: {id: string, isApproved: boolean}) => {
for(let i = 0; i < state.requestApprovals.length; i++) {
if(state.requestApprovals[i].id == value.id) {
state.requestApprovals[i].isApproved = value.isApproved;
}
}
state.requestApprovals = Object.assign([], state.requestApprovals);
return state;
});
Note: There's no tag for ngrx-component-store so couldn't tag it.
An updater can be compared to a reducer.
All the options to modify the state should change it in an immutable way.
A library like ngrx-immer can be used to make this easier.
The main difference is that updater receives the current state, and you can change the state based on it. E.g. a conditional update, or can be used with #ngrx/entity
While with setState and patchState, you just set state properties.
setState updates the whole state object, whereas patchState only sets the given properties and doesn't touch the rest of the state object.
These two methods are also easier to use when you just want to set the state, because you don't have to create an updater function.
To answer the side question, push is not immutable. Instead of creating a new instance, it updates the array instance.
Because selectOverlap function only passes through the event being overlapped, and not the selection, it is difficult to customise how to handle event creation.
In my case, we are working on a calendar/diary system, with background events showing the employee's shifts, and events showing their individual bookings.
At this point, other than the background events - absolutely no events should be able to overlap each other.
However... on top of that - we are then overlaying 'all day events' - which might be any number of things, but for examples sake, let's say they're 'staff birthdays' - therefore, you might have a couple of events today, but there will be an event in the all day section, showing someone's birthday.
I am checking for eventOverlap and doing some other checks on eventDrop and eventResize which handle different clashes, but these only work for existing events being moved or resized. I would like to do the same on event creation - which happens during the select. In order to disallow the select of spaces which already have events, I am using the example function from the selectOverlap documentation:
function(event) {
return event.rendering === 'background';
}
This works fantastically. However, if I try to create a new All Day event, it will 'overlap' any other events that exist on that day, and not pass this check.
I was hoping to be able to use the selection's object to check it for an allDay=true, but the function is only passed the existing event, and there is no way to check the selected section.
You can see a very simplified demo here:
https://codepen.io/anon/pen/NQrxOO
Try to create an allday event on the day which already has events.
Is there a better way to do this? I can completely remove the selectOverlap and do everything in the select callback instead, but I would need to essentially duplicate the overlap checks just to make this work, and I feel like that seems like overkill for something that should be relatively simple.
Is it possible to get not only the overlapped event object, but also the selection object when doing a selectOverlap function?
Current workaround is to remove the selectOverlap check, and instead do it myself within the select callback.
Below is a simplified version of a quick function I wrote to call when using select={this.handleEventCreate}:
class Diary extends React.Component {
//additional functions, state definitions, etc etc etc here.
//Define calendarRef as it will be needed in the function below
calendarRef = React.createRef();
handleEventCreate = (info) => {
// Get the Calendar API to allow unselection
let calendarApi = this.calendarRef.current.getApi();
// Get all Events
let checkEvents = calendarApi.getEvents();
// Loop through them
checkEvents.forEach(function(event){
// If it's not a background element, check whether the new element contains the existing, or vice versa.
if(event.rendering !== "inverse-background" &&
(
(event.start >= info.start && event.start <= info.end) ||
(event.end >= info.start && event.end <= info.end) ||
(info.start >= event.start && info.start <= event.end) ||
(info.end >= event.start && info.end <= event.end)
)
){
// It is an overlapping event, so we reject it.
return calendarApi.unselect();
}
});
alert('All good here to create the event.');
//extra event creation code to fire here.
}
Let's say that two users do changes to the same document while offline, but in different sections of the document. If user 2 goes back online after user 1, will the changes made by user 1 be lost?
In my database, each row contains a JS object, and one property of this object is an array. This array is bound to a series of check-boxes on the interface. What I would like is that if two users do changes to those check-boxes, the latest change is kept for each check-box individually, based on the time the when the change was made, not the time when the syncing occurred. Is GroundDB the appropriate tool to achieve this? Is there any mean to add an event handler in which I can add some logic that would be triggered when syncing occurs, and that would take care of the merging ?
The short answer is "yes" none of the ground db versions have conflict resolution since the logic is custom depending on the behaviour of conflict resolution eg. if you want to automate or involve the user.
The old Ground DB simply relied on Meteor's conflict resolution (latest data to the server wins) I'm guessing you can see some issues with that depending on the order of when which client comes online.
Ground db II doesn't have method resume it's more or less just a way to cache data offline. It's observing on an observable source.
I guess you could create a middleware observer for GDB II - one that checks the local data before doing the update and update the client or/and call the server to update the server data. This way you would have a way to handle conflicts.
I think to remember writing some code that supported "deletedAt"/"updatedAt" for some types of conflict handling, but again a conflict handler should be custom for the most part. (opening the door for reusable conflict handlers might be useful)
Especially knowing when data is removed can be tricky if you don't "soft" delete via something like using a "deletedAt" entity.
The "rc" branch is currently grounddb-caching-2016 version "2.0.0-rc.4",
I was thinking about something like:
(mind it's not tested, written directly in SO)
// Create the grounded collection
foo = new Ground.Collection('test');
// Make it observe a source (it's aware of createdAt/updatedAt and
// removedAt entities)
foo.observeSource(bar.find());
bar.find() returns a cursor with a function observe our middleware should do the same. Let's create a createMiddleWare helper for it:
function createMiddleWare(source, middleware) {
const cursor = (typeof (source||{}).observe === 'function') ? source : source.find();
return {
observe: function(observerHandle) {
const sourceObserverHandle = cursor.observe({
added: doc => {
middleware.added.call(observerHandle, doc);
},
updated: (doc, oldDoc) => {
middleware.updated.call(observerHandle, doc, oldDoc);
},
removed: doc => {
middleware.removed.call(observerHandle, doc);
},
});
// Return stop handle
return sourceObserverHandle;
}
};
}
Usage:
foo = new Ground.Collection('test');
foo.observeSource(createMiddleware(bar.find(), {
added: function(doc) {
// just pass it through
this.added(doc);
},
updated: function(doc, oldDoc) {
const fooDoc = foo.findOne(doc._id);
// Example of a simple conflict handler:
if (fooDoc && doc.updatedAt < fooDoc.updatedAt) {
// Seems like the foo doc is newer? lets update the server...
// (we'll just use the regular bar, since thats the meteor
// collection and foo is the grounded data
bar.update(doc._id, fooDoc);
} else {
// pass through
this.updated(doc, oldDoc);
}
},
removed: function(doc) {
// again just pass through for now
this.removed(doc);
}
}));
I'm in the process of learning meteor. I followed the tutorial to create microscope. If some one submits a post meteor will re render the template for all users. This could be very annoying if there are hundreds of posts then the user will come back to the top of the page and loose track of where he was. I want to implement something similar to what facebook has. When a new post is submitted template isn't rendered rather, a button or link will appear. Clicking it will cause the template to re-render and show the new posts.
I was thinking of using observeChanges on the collection to detect any changes and it does stop the page from showing new posts but only way to show them is to reload the page.
Meteor.publish('posts', function(options) {
var self = this, postHandle = null;
var initializing = true;
postHandle = Posts.find({}, options).observeChanges({
added: function(id, post) {
if (initializing){
self.added('posts', id, post);
}
},
changed: function(id, fields) {
self.changed('posts', id, fields);
}
});
self.ready();
initializing = false;
self.onStop(function() { postHandle.stop(); });
});
Is this the right path to take? If yes, how do I alert the user of new posts? Else, what would be a better way to implement this?
Thank you
This is a tricky question but also valuable as it pertains to a design pattern that is applicable in many instances. One of the key aspects is wanting to know that there is new data but not wanting to show it (yet) to the user. We can also assume that when the user does want to see the data, they probably don't want to wait for it to be loaded into the client (just like Facebook). This means that the client still needs to cache the data as it arrives, just not display it immediately.
Therefore, you probably don't want to restrict the data displayed in the publication - because this won't send the data to the client. Rather, you want to send all the (relevant) data to the client and cache it there until it is ready.
The easiest way involves having a timestamp in your data to work from. You can then couple this with a Reactive Variable to only add new documents to your displayed set when that Reactive Variable changes. Something like this (code will probably be in different files):
// Within the template where you want to show your data
Template.myTemplate.onCreated(function() {
var self = this;
var options = null; // Define non-time options
// Subscribe to the data so everything is loaded into the client
// Include relevant options to limit data but exclude timestamps
self.subscribe("posts", options);
// Create and initialise a reactive variable with the current date
self.loadedTime = new ReactiveVar(new Date());
// Create a reactive variable to see when new data is available
// Create an autorun for whenever the subscription changes ready() state
// Ignore the first run as ready() should be false
// Subsequent false values indicate new data is arriving
self.newData = new ReactiveVar(false);
self.autorun(function(computation) {
if(!computation.firstRun) {
if(!self.subscriptionsReady()) {
self.newData.set(true);
}
}
});
});
// Fetch the relevant data from that subscribed (cached) within the client
// Assume this will be within the template helper
// Use the value (get()) of the Reactive Variable
Template.myTemplate.helpers({
displayedPosts = function() {
return Posts.find({timestamp: {$lt: Template.instance().loadedTime.get()}});
},
// Second helper to determine whether or not new data is available
// Can be used in the template to notify the user
newData = function() {
return Template.instance().newData.get();
});
// Update the Reactive Variable to the current time
// Assume this takes place within the template helper
// Assume you have button (or similar) with a "reload" class
Template.myTemplate.events({
'click .reLoad' = function(event, template) {
template.loadedTime.set(new Date());
}
});
I think this is the simplest pattern to cover all of the points you raise. It gets more complicated if you don't have a timestamp, you have multiple subscriptions (then need to use the subscription handles) etc. Hope this helps!
As Duncan said in his answer, ReactiveVar is the way to go. I've actually implemented a simple facebook feed page with meteor where I display the public posts from a certain page. I use infinite scroll to keep adding posts to the bottom of the page and store them in a ReactiveVar. Check the sources on github here and the live demo here. Hope it helps!
In my client UI I have a form with differents search criterias, and I'd like to reactively update the results list. The search query is transformed into a classical minimongo selector, saved in a Session variable, and then I have observers to do things with the results:
// Think of a AirBnb-like application
// The session variable `search-query` is updated via a form
// example: Session.set('search-query', {price: {$lt: 100}});
Offers = new Meteor.Collection('offers');
Session.setDefault('search-query', {});
resultsCursor = Offers.find(Session.get('search-query'));
// I want to add and remove pins on a map
resultCursor.observe({
added: Map.addPin,
removed: Map.removePin
});
Deps.autorun(function() {
// I want to modify the cursor selector and keep the observers
// so that I would only have the diff between the old search and
// the new one
// This `modifySelector` method doesn't exist
resultsCursor.modifySelector(Session.get('search-query'));
});
How could I implement this modifySelector method on the cursor object?
Basically I think this method needs to update the compiled version of the cursor, ie the selector_f attribute, and then rerun observers (without losing the cache of the previous results). Or is there any better solution?
Edit: Some of you have misunderstood what I'm trying to do. Let me provide a complete example:
Offers = new Meteor.Collection('offers');
if (Meteor.isServer && Offers.find().count() === 0) {
for (var i = 1; i < 4; i++) {
// Inserting documents {price: 1}, {price: 2} and {price: 3}
Offers.insert({price:i})
}
}
if (Meteor.isClient) {
Session.setDefault('search-query', {price:1});
resultsCursor = Offers.find(Session.get('search-query'));
resultsCursor.observe({
added: function (doc) {
// First, this added observer is fired once with the document
// matching the default query {price: 1}
console.log('added:', doc);
}
});
setTimeout(function() {
console.log('new search query');
// Then one second later, I'd like to have my "added observer" fired
// twice with docs {price: 2} and {price: 3}.
Session.set('search-query', {});
}, 1000);
}
This doesn't solve the problem in the way you seem to be wanting to, but I think the result is still the same. If this is a solution you explicitly don't want, let me know and I can remove the answer. I just didn't want to put code in a comment.
Offers = new Meteor.Collection('offers');
Session.setDefault('search-query', {});
Template.map.pins = function() {
return Offers.find(Session.get('search-query'));
}
Template.map.placepins = function(pins) {
// use d3 or whatever to clear the map and then place all pins on the map
}
Assuming your template is something like this:
<template name="map">
{{placepins pins}}
</template>
One solution is to manually diff the old and the new cursors:
# Every time the query change, do a diff to add, move and remove pins on the screen
# Assuming that the pins order are always the same, this use a single loop of complexity
# o(n) rather than the naive loop in loop of complexity o(n^2)
Deps.autorun =>
old_pins = #pins
new_pins = []
position = 0
old_pin = undefined # This variable needs to be in the Deps.autorun scope
# This is a simple algo to implement a kind of "reactive cursor"
# Sorting is done on the server, it's important to keep the order
collection.find(Session.get('search-query'), sort: [['mark', 'desc']]).forEach (product) =>
if not old_pin?
old_pin = old_pins.shift()
while old_pin?.mark > product.mark
#removePin(old_pin)
old_pin = old_pins.shift()
if old_pin?._id == product._id
#movePin(old_pin, position++)
new_pins.push(old_pin)
old_pin = old_pins.shift()
else
newPin = #render(product, position++)
new_pins.push(newPin)
# Finish the job
if old_pin?
#removePin(old_pin)
for old_pin in old_pins
#removePin(old_pin)
#pins = new_pins
But it's a bit hacky and not so efficient. Moreover the diff logic is already implemented in minimongo so it's better to reuse it.
Perhaps an acceptable solution would be to keep track of old pins in a local collection? Something like this:
Session.setDefault('search-query', {});
var Offers = new Meteor.Collection('offers');
var OldOffers = new Meteor.Collection(null);
var addNewPin = function(offer) {
// Add a pin only if it's a new offer, and then mark it as an old offer
if (!OldOffers.findOne({_id: offer._id})) {
Map.addPin(offer);
OldOffers.insert(offer);
}
};
var removePinsExcept = function(ids) {
// Clean out the pins that no longer exist in the updated query,
// and remove them from the OldOffers collection
OldOffers.find({_id: {$nin: ids}}).forEach(function(offer) {
Map.removePin(offer);
OldOffers.remove({_id: offer._id});
});
};
Deps.autorun(function() {
var offers = Offers.find(Session.get('search-query'));
removePinsExcept(offers.map(function(offer) {
return offer._id;
}));
offers.observe({
added: addNewPin,
removed: Map.removePin
});
});
I'm not sure how much faster this is than your array answer, though I think it's much more readable. The thing you need to consider is whether diffing the results as the query changes is really much faster than removing all the pins and redrawing them each time. I would suspect that this might be a case of premature optimization. How often do you expect a user to change the search query, such that there will be a significant amount of overlap between the results of the old and new queries?
I have the same problem in my own hobby Meteor project.
There is filter session var where selector is storing. Triggering any checkbox or button changes filter and all UI rerender.
That solution have some cons and the main - you can't share app state with other users.
So i realized that better way is storing app state in URL.
May be it is also better in your case?
Clicking button now change URL and UI rendering based on it. I realize it with FlowRouter.
Helpful reading: Keeping App State on the URL