Reuse Meteor template as inclusion with different helpers - meteor

I'd like to re-use a Meteor template as an inclusion (i.e. using {{> }}) in two different contexts. I know I can pass in different data with the inclusion by using {{> templateName data1=foo data2=bar}}, but I'm struggling to figure out how I can provide different helpers based on the context. Here's the template in question:
<template name="choiceQuestion">
<div class="choice-grid" data-picks="{{numberOfPicks}}" data-toggle="buttons">
{{! Provide for the user to make multiple selections from the multiple choice list }}
{{#if hasMultiplePicks}}
{{#unless canPickAll}}<span class="help-block text-center">Pick up to {{numberOfPicks}}</span>{{/unless}}
{{#each choices}}
<label class="btn btn-default"><input type="checkbox" class="choice" name="{{this}}" autocomplete="off" value="{{this}}" checked="{{isChecked}}"> {{this}}</label>
{{/each}}
{{/if}}{{! hasMultiplePicks}}
{{#if hasSinglePick}}
{{#each choices}}
<label class="btn btn-default"><input type="radio" class="choice" name="{{this}}" id="{{this}}" autocomplete="off" value="{{this}}" checked="{{isChecked}}"> {{this}}</label>
{{/each}}
{{/if}}{{! hasSinglePick}}
</div>
</template>
and here's how I've reused it:
{{> choiceQuestion choices=allInterests picks=4}}
The key component of the template is a checkbox. In one context, it will never be checked. In another, it may be checked based on the contents of a field in the user document. I've added checked={{isChecked}} to the template. I've read this boolean attribute will be omitted if a falsey value is returned from the helper which should work well for my purposes.
The template's JS intentionally does not have an isChecked helper. I had hoped I could provide one on the parent where the template is included in the other context in order to conditionally check the box by returning true if the checked conditions are met, but the template doesn't acknowledge this helper.
Here's the template's JS:
Template.choiceQuestion.helpers({
hasSinglePick: function() {
return this.picks === 1;
},
hasMultiplePicks: function() {
return this.picks > 1 || !this.picks;
},
numberOfPicks: function() {
return this.picks || this.choices.length;
},
canPickAll: function() {
return !this.picks;
},
});
and the parent's JS:
Template.dashboard.helpers({
postsCount: function() {
var count = (Meteor.user().profile.posts||{}).length;
if (count > 0) {
return count;
} else {
return 0;
}
},
isChecked: function() {
return (((Meteor.user() || {}).profile || {}).contentWellTags || []).indexOf(this) > -1 ? 'checked' : null;
}
});
Template.dashboard.events({
'click .js-your-profile-tab': function(){
facebookUtils.getPagesAssumeLinked();
}
});
I've tried a few other approaches as well. I tried passing the helper to the template along with the other context (i.e. {{> templateName data1=foo data2=bar isChecked=isChecked}}. This kinda works, but it calls the helper immediately. This breaks these since I need to use a value from the context to determine what to return from my helper. Since this value doesn't exist when the function returns, the function always returns undefined.
If I return a function from this helper rather than the value and then pass the helper into the template inclusion along with the data context, I get better results. In fact, my console logs show the desired output, but I still don't end up with the checked box I expect.
Here's what that looks like. Returning a function:
isChecked: function() {
var self = this;
return function() {
return (((Meteor.user() || {}).profile || {}).contentWellTags || []).indexOf(this) > -1 ? 'checked' : null;
};
}
and passing that to the template:
{{> choiceQuestion choices=allInterests picks=4 isChecked=isChecked}}
Is there an established pattern for overriding template helpers from the parent or for including helpers on the parent that are missing from the child template? How can I achieve this?

Related

meteor test equality of a input value to a document field

Hello: I’m using the Tutorials todo.
I’ve been trying to compare an Input value
<input type="text" name="text" placeholder="Type Or Scan to add new Name" />
To the field named ‘text’ within a Document named ‘Tasks’.
Have tried EasySearch and {{#if $eq a b}} ... {{ /if }}.
May because I’m new to Meteor not setting up <templates> correctly.
Was hoping there is a short template or helper to compare or check the values to.
You can do this using a reactive variable.
Here's some example code:
JS:
Template.yourTemplateName.onCreated( function() {
this.input = new ReactiveVar(""); // Declare the reactive variable.
});
Template.yourTemplateName.helpers({
tasks() {
return Tasks.find(); // Find all tasks as an example.
},
isInputEqualToTaskText( taskId ) {
var task = Tasks.findOne({ _id: taskId });
if( task && task.text ) {
return task.text == Template.instance().input.get();
}
}
});
Template.yourTemplateName.events({
'change input': function( event, template ) {
template.input.set(event.target.value);
}
});
HTML:
<template name="yourTemplateName">
{{#each task in tasks}}
{{#if isInputEqualToTaskText task._id}}
<p>I was equal: {{task.text}}</p>
{{/if}}
{{/each}}
<input type="text">
</template>

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.

Template reuse in meteor

I'm trying to reuse some control elements in my Meteor app. I'd like the following two templates to toggle visibility and submission of different forms.
<template name='addControl'>
<img class='add' src='/images/icon-plus.png' />
</template>
<template name='okCancelControl'>
<img class='submit' src='/images/icon-submit.png' />
<img class='cancel' src='/images/icon-cancel.png' />
</template>
I'll call these templates in another:
<template name='insectForm'>
{{#if editing}}
<!-- form elements -->
{{> okCancelControl}}
{{else}}
{{> addControl}}
{{/if}}
</template>
editing is a Session boolean.
What's a good way to wire up the controls to show, hide and "submit" the form?
The main problem is finding the addInsect template (where the data is) from the control templates (where the "submit" event fires). Here's what I did:
First, the controls:
<template name='addControl'>
<section class='controls'>
<span class="add icon-plus"></span>
</section>
</template>
<template name='okCancelControl'>
<section class='controls'>
<span class="submit icon-publish"></span>
<span class="cancel icon-cancel"></span>
</section>
</template>
Now the javascripts. They simply invoke a callback when clicked.
Template.addControl.events({
'click .add': function(event, template) {
if (this.add != null) {
this.add(event, template);
}
}
});
Template.okCancelControl.events({
'click .cancel': function(event, template) {
if (this.cancel != null) {
this.cancel(event, template);
}
},
'click .submit': function(event, template) {
if (this.submit != null) {
this.submit(event, template);
}
}
});
I then connected the callbacks using handlebars' #with block helper.
<template name='addInsect'>
{{#with controlCallbacks}}
{{#if addingInsect}}
<section class='form'>
{{> insectErrors}}
<label for='scientificName'>Scientific Name <input type='text' id='scientificName' /></label>
<label for='commonName'>Common Name <input type='text' id='commonName' /></label>
{{> okCancelControl}}
</section>
{{else}}
{{> addControl}}
{{/if}}
{{/with}}
</template>
And the corresponding javascript that creates the callbacks relevant to this form.
Session.set('addingInsect', false);
Template.addInsect.controlCallbacks = {
add: function() {
Session.set('addingInsect', true);
Session.set('addInsectErrors', null);
},
cancel: function() {
Session.set('addingInsect', false);
Session.set('addInsectErrors', null);
},
submit: function() {
var attrs, errors;
attrs = {
commonName: DomUtils.find(document, 'input#commonName').value,
scientificName: DomUtils.find(document, 'input#scientificName').value
};
errors = Insects.validate(attrs);
Session.set('addInsectErrors', errors);
if (errors == null) {
Session.set('addingInsect', false);
Meteor.call('newInsect', attrs);
}
}
};
Template.addInsect.addingInsect = function() {
Session.get('addingInsect');
};
Template.addInsect.events = {
'keyup #scientificName, keyup #commonName': function(event, template) {
if (event.which === 13) {
this.submit();
}
}
};
In the submit callback I had to use DomUtils.find rather than template.find because template is an instance of okCancelControl, not addInsect.
You can use Session for this. You Just need a template helper that returns a boolean flag that indicates whether you are editing the form fields. And manipulate the DOM based on the Session value set by this template helper.
Assume you have one text input, now when you are entering text in it, set the Session flag as true. This will trigger the helper to return true flag, Based on that, one of your two templates will be rendered in the DOM.
The isEditing is the helper that triggers whenever you change the Session value.
This helper function is the main part here, it returns true/false based on the session value you have set.
Template.insectForm.isEditing = function(){
if(Session.get('isEditing')){
return true;
}
else{
return false;
}
}
Remember to set the Session to false at the start-up as:
$(document).ready(function(){
Session.set('isEditing', false);
})
This will render the default add template in the html, Now when you click on ADD, you need to display another template, for that, set Session to true as:
'click .add' : function(){
Session.set('isEditing', true);
}
Accordingly when you click on CANCEL, set the session to false, this will make the isEditing to return false and the default add template will be displayed.
So your complete html will look something like this:
<template name='insectForm'>
{{#if isEditing}}
<!-- form elements -->
<input type="text" id="text" value="">
{{> okCancelControl}}
{{else}}
{{> addControl}}
{{/if}}
</template>
<template name='addControl'>
<img class='add' src='/images/icon-plus.png' />
</template>
<template name='okCancelControl'>
<img class='submit' src='/images/icon-submit.png' />
<img class='cancel' src='/images/icon-cancel.png' />
</template>
[UPDATE]
To get the instance of the template, you'll need to pass the additional parameter in the event handler that represents the template.
So update your event handler as:
Template.insectForm.events = {
'click .submit' : function(event, template){
//your event handling code
}
}
The parameter template is the instance of the template from which the event originates.
Note that, although the event fires form the image that is inside the okCancelControl template, the parameter will still contain the instance of the insectForm template. This is because we are calling the event handler as Template.insectForm.events = {} .
Also see this answer for template instances.

Accessing parent context in Meteor templates and template helpers

I'm running into a template context situation that I'm having a hard time finding a way around.
Here's the template in question:
{{#each votes}}
<h3>{{question}}</h3>
<ul>
{{#each participants}}
<li>
<p>{{email}}</p>
<select name="option-select">
{{#each ../options}}
<option value="{{option}}" class="{{is_selected_option}}">{{option}}</option>
{{/each}}
</select>
</li>
{{/each}}
</ul>
</div>
{{/each}}
And here's an example of a vote document:
{
_id: '32093ufsdj90j234',
question: 'What is the best food of all time?'
options: [
'Pizza',
'Tacos',
'Salad',
'Thai'
],
participants: [
{
id: '2f537a74-3ce0-47b3-80fc-97a4189b2c15'
vote: 0
},
{
id: '8bffafa7-8736-4c4b-968e-82900b82c266'
vote: 1
}
]
}
And here's the issue...
When the template drops into the #each for participants, it no longer has access to the vote context, and therefore doesn't have access to the available options for each vote.
I can somewhat get around this by using the ../options handlebars path to jump back into the parent context, but this doesn't affect the context of the template helper, so this in Template.vote.is_selected_option refers to the current participant, not to the current vote or option, and has no way of knowing which option we are currently iterating through.
Any suggestions on how to get around this, without resorting to DOM manipulation and jQuery shenanigans?
This is a templating issue that has come up multiple times for me. We need a formal way of reaching up the template context hierarchy, in templates, template helpers, and template events.
It seems since Spacebars (Meteor's new template engine), you have access to the parent context within {{#each}} blocks using ../.
In Meteor 0.9.1, you can also write a helper and use Template.parentData() in its implementation.
It's not particularly pretty, but I've done something like this:
<template name='forLoop'>
{{#each augmentedParticipants}}
{{> participant }}
{{/each}}
</template>
<template name='participant'>
...
Question: {{this.parent.question}}
...
</template>
// and in the js:
Template.forLoop.helpers({
augmentedParticipants: function() {
var self = this;
return _.map(self.participants,function(p) {
p.parent = self;
return p;
});
}
});
It's similar to the approach that AVGP suggested, but augments the data at the helper level instead of the db level, which I think is a little lighter-weight.
If you get fancy, you could try to write a Handlebars block helper eachWithParent that would abstract this functionality. Meteor's extensions to handlebars are documented here: https://github.com/meteor/meteor/wiki/Handlebars
I don't know the formal way (if there is one), but to solve your issue, I would link the participants with the parent ID like this:
{
_id: "1234",
question: "Whats up?",
...
participants: [
{
_id: "abcd",
parent_id: "1234",
vote: 0
}
]
}
and use this parent_id in helpers, events, etc. to jump back to the parent using findOne.
That is obviously a sub optimal thing to do, but it's the easiest way that comes to my mind as long as there is no way of referencing the parent context.
Maybe there is a way but it is very well hidden in the inner workings of Meteor without mention in the docs, if so: Please update this question if you find one.
It's a long shot, but maybe this could work:
{{#with ../}}
{{#each options}}
{{this}}
{{/each}}
{{/with}}
This should make life easier.
// use #eachWithParent instead of #each and the parent._id will be passed into the context as parent.
Handlebars.registerHelper('eachWithParent', function(context, options) {
var self = this;
var contextWithParent = _.map(context,function(p) {
p.parent = self._id;
return p;
});
var ret = "";
for(var i=0, j=contextWithParent.length; i<j; i++) {
ret = ret + options.fn( contextWithParent[i] );
}
return ret;
});
Go ahead and change
p.parent = self._id;
to whatever you want to access in the parent context.
Fixed it:
// https://github.com/meteor/handlebars.js/blob/master/lib/handlebars/base.js
// use #eachWithParent instead of #each and the parent._id will be passed into the context as parent.
Handlebars.registerHelper('eachWithParent', function(context, options) {
var self = this;
var contextWithParent = _.map(context,function(p) {
p.parent = self._id;
return p;
});
return Handlebars._default_helpers.each(contextWithParent, options);
});
This works :) with no error
Simply register a global template helper:
Template.registerHelper('parentData',
function () {
return Template.parentData(1);
}
);
and use it in your HTML templates as:
{{#each someRecords}}
{{parentData.someValue}}
{{/each}}
======= EDIT
For Meteor 1.2+, you shold use:
UI.registerHelper('parentData', function() {
return Template.parentData(1);
});
I was stuck in a similar way and found that the Template.parentData() approach suggested in other answers currently doesn't work within event handlers (see https://github.com/meteor/meteor/issues/5491). User Lirbank posted this simple workaround:
Pass the data from the outer context to an html element in the inner context, in the same template:
{{#each companies}}
{{#each employees}}
Do something
{{/each}}
{{/each}}
Now the company ID can be accessed from the event handler with something like
$(event.currentTarget).attr('companyId')
"click .selected":function(e){
var parent_id = $(e.currentTarget).parent().attr("uid");
return parent_id
},
<td id="" class="staff_docs" uid="{{_id}}">
{{#each all_req_doc}}
<div class="icheckbox selected "></div>
{{/each}}
</td>
{{#each parent}}
{{#each child}}
<input type="hidden" name="child_id" value="{{_id}}" />
<input type="hidden" name="parent_id" value="{{../_id}}" />
{{/each}}
{{/each}}
The _id is NOT the _did of the thing, it's the id of the parent!

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