I'm new to both meteor and JS.
I created a meteor app like this:
cd /tmp/
meteor create hello
cd hello
In hello.html I wrote this
<body>
<h1>Welcome to Meteor!</h1>
{{> t1}}
{{> t2}}
</body>
Then I added these templates:
<template name='t1'>
<span id='t1'>hello</span>
</template>
<template name='t2'>
<span id='t2'>world</span>
</template>
Then I wrote syntax inside of hello.js to get text from the DOM:
Template.t1.onRendered( function() {
mytext = $('span#t1').html() });
According to the debugger-console in my browser,
the above syntax works okay.
The debugger tells me that mytext == 'hello'
Question: How to share the mytext value with other parts of my Meteor app?
As written, mytext is stuck inside my anonymous function.
For example how would I make this call work:
$('span#t2').html(mytext)
??
You'll want to reactively watch your variable. An easy out-of-the-box solution for this is to use the Session variable. You can do it pretty easily like so:
Template.t1.onRendered( function() {
Session.set('mytext', $('span#t1').html());
});
Then in your second template, define and reference helper that returns that variable:
<!--html-->
<template name='t2'>
<span id='t2'>{{getMyText}}</span>
</template>
//js
Template.t2.helpers({
getMyText: function() { return Session.get('mytext'); }
});
The Session variable is reactive, so when the first template renders and sets the value of Session.mytext, the helper's result will be invalidated and the second template will update.
Related
I would like to insert a string that contains a link with a helper (or is there any better option to achieve this?) in meteor blaze.
So far blaze just gives back the link as normal text with the '' tags.
Does anyone have a good solution or workaround for this?
Here is a simple example to get you started :
<template name="parent">
{{> linkTemplate linkData}}
{{#each links}}
{{> linkTemplate}}
{{/each}}
</template>
<template name="linkTemplate">
{{title}}
</template>
Links=new Meteor.Collection(null);
Links.insert({
url:"https://www.google.com",
title:"Google"
});
Template.parent.helpers({
linkData:function(){
return {
url:"https://www.google.com",
title:"Google"
};
},
links:function(){
return Links.find();
}
});
If you want to render a string in a template that happens to contain a link, you would have to provide the HTML string as in
var string="A link to Google.";
Then you can use the triple bracket syntax {{{helperReturningHTMLString}}} and it will work as expected, but I don't think it's good practice unless you're working with something like a WYSIWYG editor.
Here's what I want, a custom block helper that can act like a template, monitoring for it's own events etc. The html would look like this:
{{#expandable}}
{{#if expanded}}
Content!!!
<div id="toggle-area"></div>
{{else}}
<div id="toggle-area"></div>
{{/if}}
{{/expandable}}
And here's some javascript I have put together. This would work if I just declared the above as a template, but I want it to apply to whatever input is given to that expandable block helper.
Template.expandableView.created = function() {
this.data._isExpanded = false;
this.data._isExpandedDep = new Deps.Dependency();
}
Template.expandableView.events({
'click .toggle-area': function(e, t) {
t.data._isExpanded = !t.data._isExpanded;
t.data._isExpandedDep.changed();
}
});
Template.expandableView.expanded = function() {
this._isExpandedDep.depend();
return this._isExpanded;
};
I know I can declare block helpers with syntax like this:
Handlebars.registerHelper('expandable', function() {
var contents = options.fn(this);
// boring block helper that unconditionally returns the content
return contents;
});
But that wouldn't have the template behavior.
Thanks in advance! This might not be really possible with the current Meteor implementation.
Update
The implementation given by HubertOG is super cool, but the expanded helper isn't accessible from within the content below:
<template name="expandableView">
{{expanded}} <!-- this works correctly -->
{{content}}
</template>
<!-- in an appropriate 'home' template -->
{{#expandable}}
{{expanded}} <!-- this doesn't work correctly. Expanded is undefined. -->
<button class="toggle-thing">Toggle</button>
{{#if expanded}}
Content is showing!
{{else}}
Nope....
{{/if}}
{{/expandable}}
In the actual block helper, expanded is undefined, since the real thing is a level up in the context. I tried things like {{../expanded}} and {{this.expanded}}, but to no avail.
Strangely, the event handler is correctly wired up.... it fires when I click that button, but the expanded helper is simply never called from within the content, so even console.log() calls are never fired.
Meteor's new Blaze template engine solves this problem quite nicely.
Here's an excerpt from the Blaze docs showing how they can be used.
Definition:
<template name="ifEven">
{{#if isEven value}}
{{> UI.contentBlock}}
{{else}}
{{> UI.elseBlock}}
{{/if}}
</template>
Template.ifEven.isEven = function (value) {
return (value % 2) === 0;
}
Usage:
{{#ifEven value=2}}
2 is even
{{else}}
2 is odd
{{/ifEven}}
You can achieve this by making a helper that returns a template, and passing the helper options as a data to that template.
First, make your helper template:
<template name="helperTemplate">
<div class="this-is-a-helper-box">
<p>I'm a helper!</p>
{{helperContents}}
</div>
</template>
This will work as a typical template, i.e. it can respond to events:
Template.helperTemplate.events({
'click .click-me': function(e, t) {
alert('CLICK!');
},
});
Finally, make a helper that will return this template.
Handlebars.registerHelper('blockHelper', function(options) {
return new Handlebars.SafeString(Template.helperTemplate({
helperContents: new Handlebars.SafeString(options.fn(this)),
}));
});
The helper options are passed as a helperContents param inside the template data. We used that param in the template to display the contents. Notice also that you need to wrap the returned HTML code in Handlebars.SafeString, both in the case of the template helper and its data.
Then you can use it just as intended:
<template name="example">
{{#blockHelper}}
Blah blah blah
<div class="click-me">CLICK</div>
{{/blockHelper}}
</template>
I'm learning meteor to build quick website prototypes.
I'm trying to understand how to generate a set of values to populate the site templates and partials.
I have a layout.html template
<template name="layout">
<div class="container">
<header role="banner">
{{>site-header}}
</header>
<h1>This is {{siteLogo}}</h1>
<main role="main">
{{ yield }}
</main>
<footer role="contentinfo">
{{> site-footer }}
</footer>
</div>
</template>
in main.js I define the following:
Meteor.startup(function(){
Session.set('siteLogo', 'the logo');
});
Template.site-header.helpers({
siteLogo: function(){ return Session.get('siteLogo'); }
});
Template.layout.helpers({
siteLogo: function(){ return Session.get('siteLogo'); }
});
With this i can pass the value of siteLogo to layout.html.
I have a site-header.html partial
<template name="site-header">
<h1>{{siteLogo}}</h1>
</template>
I can't seem to be able to pass the value of siteLogo to the partial. Is there a way to do that?
Is it necessary to create a Session variable to pre-fill some values or can i just create a json settings list and access the value globally?
something that would go in main.js, like the yaml config file in a jekyll site:
siteSettings = [
{
siteLogo: "some brand name",
otherValue: "something else"
}
]
update
I'm a bit confused, I'm must be doing something wrong.
I've created a quick new meteor app to test this.
I have main.html
<head>
<title>handlebar-helper</title>
</head>
<body>
{{> header}}
{{> hello}}
{{> footer}}
</body>
<template name="hello">
<h1>Hello World!</h1>
{{greeting}}
<input type="button" value="Click" />
</template>
<template name="header">
<header>
<h1>{{ headline }}</h1>
<p>tagline</p>
</header>
</template>
<template name="footer">
<footer role="contentinfo">
<h1>{{ headline }}</h1>
<small>copyright</small>
</footer>
</template>
And main.js
if (Meteor.isClient) {
Template.hello.greeting = function () {
return "Welcome to handlebar-helper.";
};
Template.hello.events({
'click input' : function () {
// template data, if any, is available in 'this'
if (typeof console !== 'undefined')
console.log("You pressed the button");
}
});
Meteor.startup(function(){
Session.set('headline', 'My fancy headline');
});
Handlebars.registerHelper('headline', function(){
return Session.get('headline');
});
}
if (Meteor.isServer) {
// server code here
}
And i can't still pass the value of headline into >header of >footer
if I try to put the Session.set into the Meteor.isServer block, I get a syntax error, Session is not defined
Cheers
Do you have a Template.site-header.helpers function declared for siteLogo? If not it won't work - you can't use a helper from another template. If you need to use siteLogo in a variety of places, it's best to use a Handlebars block helper, as these can be accessed by any template.
UPDATE
The Handlebars helper would just look like this:
Handlebars.registerHelper('siteLogo', function() {
return Session.get('siteLogo');
});
However, if you've already got a siteLogo helper in the site-header Template, it suggests something else is wrong, like a typo in a template or helper name. Is there an error in the console?
UPDATE 2
If you want to use a dictionary-style structure to store reactive data, you can do something like this:
Session.set('myDict', {foo: 1, bar: 2});
Handlebars.registerHelper('myDict', function(key) {
return Session.get('myDict') ? Session.get('myDict')[key] : null;
});
And then use this in your template: {{myDict 'foo'}}. Obviously, the format above would work fine in a tempate helper as well, but it would only be accessible from within that template. The ternary operator is just to check that myDict has been initialised before it lets a template try to look up one of the keys, which is a common Meteor problem on page load.
Incidentally, if you're finding Session variables a cumbersome way to deal with reactive dictionary-like data structures, it's pretty easy to roll your own. This is the best introduction.
Having troubles understanding how to return and use an object from findOne().
my code is this:
Html:
<head>
<title>count</title>
</head>
<body>
{{> hello}}
</body>
<template name="hello">
{{showcount}}
</template>
Js:
var Database = new Meteor.Collection("counters");
if(Meteor.is_client) {
Template.hello.showcount = function () {
var c = Database.findOne();
return c;
};
}
if (Meteor.is_server) {
Meteor.startup(function () {
if(Database.find().count() === 0)
{
Database.insert({name: "counter", value: 0});
}
});
}
Now I'm wondering if there is any way I can access the data from my object.
changing from {{showcount}} to {{showcount.name}} doesn't seem to work at all.
This same issue got me a few times when I started out with Meteor...
When the Meteor client connects to the server the template is being rendered before the collections have finished being synchronised. i.e. The client collection is empty at the point you are calling findOne.
To see this in action stick a console.log(c) after your findOne call then try reloading the page. You will see two log entries; Once on initial page load and then again when the collection has finished being synchronised.
To fix this all you need to do is update your hello template to handle the fact the collection might not have been synchronised.
{{#if showcount}}
{{showcount.name}}
{{/if}}
I tested your code with the above change and it works.
The proper way to do this is with the #with tag.
<template name="hello">
{{#with showcount}}
{{name}}
{{/with}}
</template>
See the documentation below for more info on the #with tag
https://github.com/meteor/meteor/blob/devel/packages/spacebars/README.md
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);
}
});