Meteor/Handlebars #if not auto-updating - meteor

I'm just getting started with Meteor, and I'm a little confused; I'm not sure if this is a Meteor issue or a Handlebars issue.
I'm trying to create a nested menu (a set of clickable divs, each of which toggles a submenu consisting of more clickable divs). I want the submenus to be hidden by default but appear when the user clicks their parent.
This is what I've got:
Template.sidebutton.events({
click : function() {
this.clicked = !this.clicked;
clickHandlers[this.label]();
}
})
and
<template name = "sidebutton">
<div class = "sidebutton" id = "sidebutton_{{label}}"><p>{{label}}</p></div>
{{#if clicked}}
{{#each submenus}}
{{> submenu}}
{{/each}}
{{/if}}
</template>
I've verified that the onclick function fires when I click; this.clicked is toggled and my click handlers are called. I've also verified that the submenus appear if I strip out the #if block or if I set clicked to true on the initial page load. But the submenus do not appear when I click.
Is there something more I need to do? Everything I find about Meteor seems to imply that if I change any of the data, affected objects are re-rendered, but it seems like they're not being re-rendered here.

I suppose "clicked" is in your mongodb db collection element, in this case, you cannot change its value like you do. You have to call somthing like that :
myCollection.update(_id, {clicked:!clicked});

Related

How to prevent firebase-query element to updating the data

I am using polymer and firebase to create a web app. To get a list in the database, I am using the "firebase-query" element of polymerfire.
Now, the list of items I am getting from the database is posts that people are posting on my app. Now I have the firebase-query element like this:
<firebase-query
id="query"
path="/posts"
limit-to-last="15"
data="{{posts}}">
</firebase-query>
and I have dom-repeat template tag to display the posts like this
<template is="dom-repeat" items="[[posts]]" as="post">
<div>[[post.content]]</div>
</template>
Now, if I have bunch of people posting a lot of contents at once, this list would be updating every second, and it would be hard to read.
Is there a way to prevent firebase-query element to stop updating once the initial load is complete, and possibly updating again when I call a certain function?
I tried to add a disabled attribute, but that just deletes whatever is inside the data attribute ({{posts}} in my case), so when disabled is set, nothing shows up on the screen.
I am not familiar with firebase-query, but you can do simple trick. On property posts set observer function.
posts: {
Type: Array,
value: function(){return []},
observer: "debouncePosts"
}
then in js you can define debounce function where I set, for example, 10 000 miliseconds (10 seconds) and called some callback function where I set this.posts to currentPosts property which will be rendered in template.
debouncePosts: function(data) {
this.debounce("debouncePost", function(){
this.set("currentPosts", this.posts);
}.bind(this), 10000)
}
and html template will be like:
<template is="dom-repeat" items="[[currentPosts]]" as="post">
<div>[[post.content]]</div>
</template>
documentation to debounce: https://www.polymer-project.org/1.0/docs/api/Polymer.Base#method-debounce
If you like to do it in different way like update data whenever user presses update, it's really easy now for you. Just set on-tap on some button and then in function you will do something like this.set("currentPosts", this.posts)

Meteor infinite scroll : prevent subscribe to rerender elements

I'm implementing an infinite scroll on Meteor in order to display a grid of pictures linked to a large collection.
When the user is at the end of the page I subscribe to more elements and I increase the number of pictures displayed (through my template.helper).
//SERVER
Meteor.publish('generalMusics', function(limit){
return Musics.find({}, {limit: limit});
});
//CLIENT: when the template is created and when the limit of data increases
//it subscribes again
Template.t_elementSubHeader.onCreated( function() {
Session.set('reqLimit',50);
var self = this;
//Everytime reqLimit changes I redo the subscribe
this.autorun(function(){
self.subscribe('generalMusics', Session.get('reqLimit'));
});
//CLIENT: more elements are sent to the template when reqLimit increases
Template.t_elementSubHeader.helpers({
data: function() {
return Musics.find({}, {limit : Session.get('reqLimit')});
}
});
//Also on client, when the user reach the bottom of the page
Session.set('reqLimit',Session.get('reqLimit')+50);
It works well but all the template elements are re-rendering and it also takes some time to do so. It's very inconvenient for the user, I think it takes time because I'm displaying pictures and not text (we already compress the pictures to a minimum size).
The problem is due to the subscribe that rerender all the template elements.
How can I do to just add the new elements and prevent the re-rendering of the already displayed elements when I subscribe ?
My app will be on mobile devices so I can't subscribe to a lot of elements and then just increase the limit in the template helper.
Finally I got it, i've added some code in the html to wait the subscription to be ready and I forgot about it.
I removed:
{{#if Template.subscriptionsReady}}
{{> Template.dynamic template="t_elementList" data=tabData}}
{{/if}}
Infinite scroll is working like a charm.

Execute route change before event function

I've got a list of menu items and each is an a tag. Inside those, I've got notification bubbles insides a div. When the notification div is clicked, I'd like to first follow the a tag (the hash is always to a Meteor route, using Iron Router) before it executes the click event attached to the div. Since reverse-propagation hasn't existed since the netscape days, I thought maybe that click event could store a function as a callback when the route changes? Has anyone tried to do something similar? Couldn't find anything in the Iron Router docs about it. I'm currently mitigating the problem with a few Session vars, but would like to clean it up.
Without seeing what your code is currently doing (or even better, a simplified example), I am guessing a bit at what you are trying to do. Maybe you have something like this:
<div id="bubblething">Click Me!</div>
With a click event:
'click #bubblething': function() {
// Do the bubble thing.
}
But the problem is you'd like to trigger the click event after you route but the click is happening to early. Would it be possible to change it to something more like this:
<div id="bubblething">Click Me!</div> //no <a> tag.
With the click event handling the actually routing first then moving on:
'click #bubblething': function(){
Router.go('/yourroute'); // First you route
{ ... } // Code to handle the notification bubble.
}
You may have to update your styling a bit do to the lack of am <a> tag but that should be pretty simple. The routing is handled by the click and then other things happen. You can parameterize this so that instead of calling an id you call a class and inject the route.

How can I simulate a click event on an anchor tag without actually calling click or refreshing?

I am using meteor with iron router and meteors standard blaze tempting.
I have an ul set up so that when one of my li items is clicked its containing anchor tag is clicked on using the function click. The only problem is that when that a is clicked with the function it counts as another click on my li and my menu isn't toggling right.
I am wondering if there is a way to call the pathFor without actually calling a click function.
Thanks for any help!
Update, here is the code its working along with a pretty standard drop down nav. I am not sure if I can catch that event the same as a jquery event since I think it is the standard browser click event working on the [0], but I think I should be able to make a function that matches href to route and call Router.go
Template.nav.rendered = () ->
# set initial page view and take care of refeshes
currentPageHtlm = getCurrentPage(window.location.pathname)
$('#currentPage').find('span').html(currentPageHtlm)
$("li").on "click", () ->
#simulate anchor click and set currentPage session
$(this).find("a")[0].click()
Session.set 'pageName', getCurrentPage($(this).find("a").attr("href"))
currentPageHtlm = Session.get 'pageName'
$('#currentPage').find('span').html(currentPageHtlm)
# toggle nav and arrow if mobile view
if $('.smOnly').css('display') != 'none'
$('#nav').slideToggle('slow')
$('#dropArrow').toggleClass('fa-caret-square-o-down fa-caret-square-o-up')
It sounds like you're looking for a way to programatically redirect from JS rather than via UI interaction, in which case you need to use Router.go('ROUTE_NAME'), as per the docs (you can use the route name as in pathFor as an alternative to supplying the actual path).

Can you force a hyperlink click event on page load

I've implemented a menu for my asp.net page containing some hyperlinks and loading different contents on their clicks, it's using jquery on behind for it's style mostly and it is working fine. But the problem is, what if a refer to this menu from the outside, i can refer to each of the menu items, i pass parameters on querystring, now i can find which item is clicked but how can i force that hyperlink menu item to be clicked on page load. I'm specifing just their navigation urls, how can i specify that if something is passed in querystring than that specific menu item should be forced clicked on pageload.
Any ideas? Thanks in advance.
The real question lies can you cuase a hyperlink click event?
Now I'm using
Page.ClientScript.RegisterStartupScript(typeof(Page),"test1", "<script>document.getElementById('linkButtonId').click();</script>"); but still nothing desirable happens, seems that this row has no effect at all.
Whether the functionality being executed is client side or server side, it might be a good idea to create a function that will accept the id or something of the menu item being clicked and then handle it appropriately.
Thus all the menu items will call the same function. And since you have the parameters in the query string just pass them through to the function which will handle it accordingly and display the correct content?
You need a bit of separation...
Whatever your click does can be moved into a function, then you can call the function on the click of the menu - but you can also call the function at other times as well.
Before:
<a ... onclick="alert('hello');">Click Me</a>
After:
<a ... onclick="fnSayHello();">Click Me</a>
...
var fnSayHello = function() { alert('hello'); };
fnSayHello();

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