Can Meteor handle nested views? - meteor

Question

I'm learning meteor, and finding all kinds of difficulties dealing with nested subviews. Since the application I want to write is full of them... that looks like a difficulty. I found this on github, as a readme for a Meteor project to try and deal with this problem.
"I've been playing around with Meteor for a couple weeks. The ease of setup and the powerful reactivity makes this something I want to stick with. I was however frustrated by the difficulty of programmatically configuring, instantiating, destroying and nesting subviews."
Is this an issue that can be handled in Meteor (without adding a lot of complicated work arounds) or should I look for a different platform ?

Answer 1

I love nesting templates. I get reliable results. I now program off a library of both templates and helper functions (usually for form elements) that compose html for me. HTML is a byproduct, and the files we call .html are really a javascript DSL.
There are many S.O. issues raised about insertions into sorted lists giving people problems. I haven't had time to look.
My rule of thumb: Meteor is (well) designed from the beginning to do this easily and reliably.
So far the harder thing to solve was when I added an accordion from foundation, and a refresh of the document led to its initial state (being all closed, or one open). I had to put code in that saved the current section, and code to re-assert that in the rendered callback for the template that used it.
Why not write a prototype of the nesting with just a field or two in places, and find what bothers you?
Here is a sample chain. You see all the nested templates. This template itself is running within multiple.
First template: called 'layout', suggested by iron router. Has basic page and menu. Main body is a yield, set by router. On a sample page, a route calls template 'availability'
<template name='availability'>
{{#each myAgents}}
<form class="custom" id="Agent_{{_id}}" action="">
<div id='availability' class="section-container accordion" data-section="accordion">
<section id="services">
<p class="title" data-section-title><a href="#">
Your Info
</a></p>
<div class="content" data-section-content>
{{>services}}
</div>
</section>
<section id="skills">
<p class="title" data-section-title><a href="#">
Skills
</a></p>
<div class="content" data-section-content>
{{>skills}}
</div>
</section>
<section id="sureties">
<p class="title" data-section-title><a href="#">
Sureties
</a></p>
<div class="content" data-section-content>
{{>sureties}}
</div>
</section>
<section id="time">
<p class="title" data-section-title><a href="#">
Time Available
</a></p>
<div class="content" data-section-content>
{{>time}}
</div>
</section>
<section id="schedule1">
<p class="title" data-section-title><a href="#">
Schedule 1
</a></p>
<div class="content" data-section-content>
{{>schedule}}
</div>
</section>
<section id="schedule2">
<p class="title" data-section-title><a href="#">
Schedule 2
</a></p>
<div class="content" data-section-content>
{{>schedule}}
</div>
</section>
<section id="distance">
<p class="title" data-section-title><a href="#">
Distance
</a></p>
<div class="content" data-section-content>
{{>distance}}
</div>
</section>
</div>
</form>
{{/each}}
</template>
sample further nest:
<template name='services'>
{{label_text fname='name' title='Agent Name' placeholder='Formal Name' collection='agent' passthrough='autofocus=autofocus ' }}
{{label_text fname='agentInCharge' title='Agent In Charge' placeholder='Owner' collection='agent' }}
{{label_text fname='phone' title='Phone Number(s)' placeholder='Include Area Code'collection='agent' }}
{{>gps }}
<h4>Not shared:</h4>
{{label_text fname='email' title='Email:' placeholder='you remain anonymous' collection='agent' }}
</template>
and label_text is a helper, learned from the https://github.com/mcrider/azimuth project:
generateField = (options) ->
options.hash.uniqueId = options.hash.fieldName + "_" + Math.random().toString(36).substring(7) if options.hash.template is "wysiwyg"
options.hash.id = options.hash.id or #_id
options.hash.value = options.hash.value or this[options.hash.fname]
# allow for simple params as default
options.hash.title = options.hash.title or options.hash.fname
options.hash.template = options.hash.template or "label_text"
options.hash.placeholder = options.hash.placeholder or options.hash.title
# compatible with old
options.hash.fieldName = options.hash.fieldname or options.hash.fname
options.hash.label = options.hash.label or options.hash.title
# FIXME: Return error if type not valid template
new Handlebars.SafeString(Template[options.hash.template](options.hash))
Handlebars.registerHelper "label_text", (options) ->
options.hash.collection = options.hash.collection or 'generic'
generateField.call this, options

Answer 2

I am fairly new to Meteor, but I found out really soon that I wanted nested views (aka dynamic includes or sub-templates). I'm not sure whether this is what you mean, but here is my solution.
I created the following handlebars helper, that can be used to create sub-templates:
Handlebars.registerHelper('subTemplate', function(container, property, context, options) {
if (container && container.hasOwnProperty(property)) {
var subTemplate = container[property];
if (typeof subTemplate === 'function') {
return new Handlebars.SafeString(subTemplate(context || this));
}
else if (typeof subTemplate === 'string') {
return new Handlebars.SafeString(Template[subTemplate](context || this));
}
}
});
It can be used inside something I call a generic template. For example to create a list:
<template name="item_list">
<ul class="items-list">
{{#each items}}
<li class="listview-item">
{{subTemplate .. 'listItem' this}}
</li>
{{/each}}
</ul>
</template>
Now invoking this generic template requires that a 'listItem' property is present within its context. This can be either a string with the name of the sub-template, or the inline definition of a sub-template. The example below shows both options:
<template name="my_list">
{{! First option, referring to the sub-template by name:}}
<div>
{{#with listData listItem="my_list_item"}}
{{> item_list}}
{{/with}}
</div>
{{! Second option, inlining the sub-template:}}
<div>
{{#with listData}}
{{#assignPartial 'listItem'}}
<span>{{name}}</span>
{{/assignPartial}}
{{> item_list}}
{{/with}}
</div>
</template>
<template name="my_list_item">
<span>{{name}}</span>
</template>
Template.my_list.listData = function() {
return {
items: collections.people.find()
};
};
The second option requires an extra handlebars helper.
Handlebars.registerHelper('assignPartial', function(prop, options) {
this[prop] = options.fn;
return '';
});
I made more of these kinds of useful helpers, at some point I will probably share them on GitHub.