'this' context in Meteor event is empty object - meteor

Template works fine (in terms of data being displayed), but event doesn't. Particularly odd because I have a different template with almost the identical code in which it works.
<template name="profile_sidebar">
{{#if opened}}
{{> profile_sidebar_contents}}
{{/if}}
</template>
<template name="profile_sidebar_contents">
{{#if dataReady}}
{{#unless equalsCurrentUsername profile.login}}
<span>
<a class="message-user"><i class="ion-chatbox"></i> Message</a>
</span>
{{/unless}}
{{/if}}
</template>
Template.profile_sidebar_contents.events({
'click .message-user': function(e,t){
// this is {}
// t.data is null
Session.set('selectedConversation', this._id);
Router.go('/messages');
}
});
Thank you!

Found a solution!
I wrapped the entire template in a {{#with profile}} ... {{/with}} block and then added the data I needed to be within the profile object returned in the helper. It seems as though the context of the event was empty object because the event target was not within a scope.
Elaborated below
I assumed that the context would default to an object which had as fields all helpers. Ex. I had
Template.profile_sidebar_contents.helpers({
profile: function(){ return something },
id: function() {return somethingelse }
});
and I expected the context of this to be {profile: something, id: somethingelse}
but it seems that this isn't done and the context is empty. I moved it to be
Template.profile_sidebar_contents.helpers({
profile: function(){ return {profile:something, id:somethingelse} }
});
and then set {{#with profile}} ... {{/with}} and had access to the profile helper returned object, by which I could retrieve id by this.id and profile by this.profile

Related

Meteor: Spacebars each parameter

I'm new to Meteor.js and have run into a problem.
I am passing in a user object to a profile template e.g.:
{
_id: "D8JpXRQskm3grykjg",
username: "foo",
profile: {communities: ["AkGCakz6mSgMb8qyS", "j8aB3i5iscrC4ehkA"]},
}
<template name="profile">
<h1> {{username}}: {{_id}} </h1>
<h3>Communities</h3>
<hr>
{{#each profile.communities}}
{{> communityItem}}
{{/each}}
</template>
The problem is I've already written a communityItem template that I am using elsewhere which accepts the communityName. Is there a way that I can write a helper function, passing in the communityIds list that would return a list of community names? I would like:
...
{{#each getCommunityNames(profile.communities)}}
{{> communityItem}}
{{/each}}
...
I could very well be approaching the problem the wrong way or not writing in a "Spacebars" fashion. Thanks!
sure you can:
Template.myTemplate.helpers({
getCommunityNames: function(commIds) {
var communities = Communities.find({_id: {$in: commIds}}).fetch();
return _.pluck(communities, 'name'); // returns ['Name 1', 'Name 2'];
}
});
Note, the syntax method param not method(param)
{{#each getCommunityNames profile.communities}}
{{>communityItem}}
{{/each}}

Rendering Template in Meteor and Iron Router depending on value in document

I am trying to render a template depending on a value of a field in a document.
I tried using a switch case in a helper but the return value comes out incorrect.
units_list.html
<template name="unitsList">
{{#each units}}
{{> unitItem}}
{{/each}}
</template>
units_list.js
Template.unitsList.helpers({
units: function() {
return Units.find({}, {sort: {name: 1}});
}
});
unit_item.html
<template name="unitItem">
{{name}}
</template>
unit_item.js
Template.unitItem.helpers({
unitType: function() {
var unitType = this.unitType;
switch(unitType){
case 'first': return "{{pathFor 'unitPageFirst'}}";
case 'second': return "{{pathFor 'unitPageSecond'}}";
}
}
});
I'm either going about this the wrong way or missing something elementary...
I've cut out a lot of code to focus on the problem.
Any ideas on how to get this working, or any suggestions on how to do it better?
You can't return uncompiled Spacebars strings from JS at execution time.
You can either use Router.path to get the path for your routes within your template helper :
Template.unitItem.helpers({
unitType: function() {
var unitType = this.unitType;
switch(unitType){
case 'first':
return Router.path('unitPageFirst', this);
case 'second':
return Router.path('unitPageSecond', this);
}
}
});
Or you can use plain Spacebars by declaring template helpers to check against the unitType.
HTML
<template name="unitItem">
{{#if unitTypeIs 'unitTypeFirst'}}
{{name}}
{{/if}}
{{#if unitTypeIs 'unitTypeSecond'}}
{{name}}
{{/if}}
</template>
JS
Template.unitItem.helpers({
unitTypeIs: function(unitType){
return this.unitType == unitType;
}
});
Have a look at Rendering Templates in the Iron-router guide, specifically the this.render('xyz'); statement
https://github.com/iron-meteor/iron-router/blob/devel/Guide.md#rendering-templates

How to deal with the situation that template is rendered but the data is not ready?

In client startup I subscribe to something:
Meteor.publish("Roles", function(){
return Roles.find();
});
Meteor.startup(function() {
if(Meteor.isClient) {
Meteor.subscribe('Roles');
}
});
And roles template:
Template.roles.helper(function() {
allRoles: function() {
return Roles.find().fetch();
}
})
<template name="roles">
<div>
{{#with allRoles}}
<label>{{> role }}</label>
</div>
</template>
The problem is sometime roles template is rendered before the Roles is ready.
How to deal with this situation?
You can do the subscribe on the template and then use the Template.subscriptionReady helper to create a conditional to show a loading panel whilst your subscription is being loaded as follows:
Template.roles.onCreated(function () {
this.subscribe("Roles");
});
Template.roles.helper(function() {
allRoles: function() {
return Roles.find().fetch();
}
})
<template name="roles">
<div>
{{#if Template.subscriptionsReady}}
{{#with allRoles}}
<label>{{> role }}</label>
{{else}}
Loading...
{{/if}}
</div>
</template>
This replaces your other subscription and these subscriptions can be added to each onCreated method for each template to have subscriptions per template.
There are some common ways of dealing with it. You can use a guard or make use of iron router's waitOn function. With a guard you only return data from the helper if you're getting any results:
allRoles: function() {
var roles = Roles.find();
//explicit version
if (roles.count()) return roles
//implicitly works as well here because you're returning null when there are no results
return roles
}
You don't need the fetch() in this case, because #with works with a cursor. If you run into a situation where you need to fetch first because you're returning partial data, check that there are results first and only then return them.
You can also use iron router's waitOn Option if you're using this as part of a route.

Meteor template: Pass a parameter into each sub template, and retrieve it in the sub-template helper

I am trying to figure out how to pass a parameter into a sub-template that is in an each block and use the parameter in the sub-template as well as sub-template helper. Here is what I tried so far:
template:
<template name="parent">
{{#each nodes }}
{{> child myParam}}
{{/each}}
</template>
<template name="child">
{{ paramName }}
</template>
js:
Template.parent.nodes = function() {
//return a list
};
Template.parent.myParam = function() {
return {"paramName" : "paramValue"};
};
Template.child.someOtherHelper = function() {
//How do I get access to the "paramName" parameter?
}
So far, it hasn't been working, and it seems somehow mess up my input node list also.
Thanks for help.
When you use {{> child myParam}}, it's calling the child template and associates myParam as current template data context, meaning that in the template you can reference {{paramName}}.
In someOtherHelper you could use this.paramName to retrieve "paramValue".
However, when you're using {{#each nodes}}{{> child}}{{/each}}, it means that you pass the content of the current list item (fetched from a LocalCursor or directly an array item) as the template data of child, and you can reference the list item properties using {{field}} in html or this.field in js.
What's happening here is when you call {{> child myParam}}, the myParam helper content OVERWRITES the current node item as template data, that's why it's messing your node list.
A quick (dirty) trick would be to simply extend the myParam helper so that it also contains the template data from the {{#each}} block.
Template.parent.helpers({
nodes:function(){
// simulate typical collection cursor fetch result
return [{_id:"A"},{_id:"B"},{_id:"C"}];
},
myParam:function(){
// here, this equals the current node item
// so we _.extend our param with it
return _.extend({paramName:"paramValue"},this);
}
});
Template.child.helpers({
someOtherHelper:function(){
return "_id : "+this._id+" ; paramName : "+this.paramName;
}
});
<template name="parent">
{{#each nodes}}
{{> child myParam}}
{{/each}}
</template>
<template name="child">
{{! this is going to output the same stuff}}
<div>_id : {{_id}} ; paramName : {{paramName}}</div>
<div>{{someOtherHelper}}</div>
</template>
Depending on what you're precisely trying to achieve, there might be a better approach but this one gets the job done at least.

Cannot read property '_liveui' of null

I'm getting client side errors(console.log ones) but my app works(I can add users)
The error is the following:
Uncaught TypeError: Cannot read property '_liveui' of null
The project is in my repo:
https://github.com/thiagofm/statusfyit
What is happening?
Meteor has updated its API a bunch since this question was asked, so the original code no longer runs directly.
Using jQuery.html to insert the results of rendering a template is not the normal approach. It is better to use the handlebars template include functionality.
For example, replace:
$().ready(function(){
hello = Meteor.ui.render(function(){
return Template.hello();
});
$('body').html(hello);
});
With:
<body>
{{> hello}}
</body>
To render different things depending on the state of the application, use the 'Session' object to conditionalize includes. For example:
<template name="foo">
{{#if showNewUserDialog}}
{{> newUserDialog}}
{{else}}
other stuff
{{/if}}
</template>
<template name="newUserDialog">
some stuff
</template>
and
Template.foo.showNewUserDialog = function () {
return Session.get('showNewUserDialog');
};
Template.other.events({
'click #new_user': function () {
Session.set('showNewUserDialog', true);
}
});

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