I have collection that has a document object "wageringStraightSpread" that sometimes is an embedded array. I need to check then look through the array, but i am not sure of the syntax of the {{if}} statement. I am specifically looking for help with this line {{#if team.[0].wageringStats.wageringStraightSpread = array}}. Thank you!
Here's what I got:
{{#if team.[0].wageringStats.wageringStraightSpread = array}}
{{#each}}
{{team.[0].wageringStats.wageringStraightSpread.this.line}}
({{team.[0].wageringStats.wageringStraightSpread.this.money}})
{{/each}}
{{else}}
{{team.[0].wageringStats.wageringStraightSpread.line}}
({{team.[0].wageringStats.wageringStraightSpread.money}})
{{/if}}
You can create a isArray helper that does the check:
Template.layout.helpers({
isArray: function(a){
return Array.isArray(a);
}
});
And use it from your html with:
{{#if isArray someVariable}}
First of all, your if condition is wrong. it is supposed to ==, not =. However, that is not the case, because if of Meteor template does not support boolean operation. Therefore, you will have to have a helper for this
Template.layout.helpers({
checkArray: function() {
// return the result of the comparison of
// team.[0].wageringStats.wageringStraightSpread == array.
// you do need to find the way to compare the array since == is also wrong
// for comparing the array
}
});
{{#if checkArray}}
{{/if}}
Related
I am using a helper inside another helper. I am trying to pass a value ‘post_id’, that i am getting dynamically from ‘show_post’ helper.I want to pass it and then use it inside the query that is returning a set of result back to helper. for some reason , app is crashing. Can someone guide me through this.
{{#each show_post}}
{{posttext}}
{{postedBy}}
{{#each show_comment({{post_id}}) }}
//<--- i am passing the value to helper like this.
<span> <p>{{postedBy}}: <h5>{{commenttext}}</h5>{{createdAt}}</p></span>
{{/each}}
{{/each}}
Template.display_block.helpers({
show_post(){
return PostComment.find({parent: 0},{sort: {createdAt: -1}});
}
});
Template.display_block.helpers({
show_comment(e){
var t1 = e;
var now = PostComment.find({post_id:{$regex:new RegExp(’^’ + t1)}});
return now;
}
});
The first helper generates a array(Mongo Db result).I want to use this array’s elements(that are dynamic) in next helper. So i want to use a variable that can hold the value of array element of first helper and then pass it to next helper. In second helper, i want to pass this variable and use this variable to sort a result in Mongo query. I am new to this so i am unable to understand how this instance
Firstly you don't need to wrap helper arguments in double curly braces or parens.
{{#each show_comment post_id}}
Will do what you need.
You're also making life a bit more complicated for yourself than necessary. You can use the current data context through this in your code. Also unclear why you're using a regex unless you're concatenating something to the post _id.
This allows you to simplify down to:
html:
{{#each show_post}}
{{posttext}}
{{postedBy}}
{{#each show_comment}}
<span><p>{{postedBy}}: <h5>{{commenttext}}</h5>{{createdAt}}</p></span>
{{/each}}
{{/each}}
js:
Template.display_block.helpers({
show_comment(){
return PostComment.find({post_id: this._id);
}
});
I am looping through documents in a template with Blaze spacebars to create a list
<template name="objectTemplate">
{{#if checkIfObjectExists}}
({{document.[0].object.object1}})
{{/if}}
</template>
I know that in some documents, some objects do not exist in that object position. normally if I didnt have (), it would be blank and I could move on, but in this case when empty, I will have a lot of () which is not good.
I created a helper, but its not working. I have tried null, 0, typeOf etc and still cant get it right. Anyhow here is the helper
Template.objectTemplate.helper ({
checkIfObjectExists: function() {
if (this !== 'null') {
return true;
} else {
return false;
}
}
});`
You can use _.has(object, key) if you want to check if the object document.[0].object has the property object1 set. The function _.isObject(value) will check instead if document.[0].object.object1 is an Object (this also includes arrays).
So, depending on your requirements, your template helpers should look like this:
Template.objectTemplate.helper({
checkIfObjectPropertyExists: function() {
return _.has(this.document[0].object, "object1");
},
checkIfPropertyIsObject: function() {
return _.isObject(this.document.[0].object.object1);
}
});
You could also register an Underscore.js global template helper and then use it directly in your Meteor templates:
Template.registerHelper('_', function () {
return _;
});
<template name="objectTemplate">
{{#if _.has this.document.[0].object 'object1'}}
({{document.[0].object.object1}})
{{/if}}
</template>
Your if is not in the right place. Your objectTemplate is probably called that way :
{{#each datum in data}}
{{>objectTemplate data=data}}
{{/each}}
So it's always rendered. Even if the datum is empty. The this you check in your helper will always be true, it's the template himself.
So, you should call it that way :
{{#each datum in data}}
{{#if datum.thingToTest}}
{{>objectTemplate datum=datum}}
{{/if}}
{{/each}}
The entire sub template won't be called.
I have this html-File in Meteor
{{#if thevalue}}
{{> one}}
{{else}}
{{> two}}
{{/if}}
and this helper
'thevalue': Session.get('thevalue') //returns true or false
My problem is that when the Session-Value changes, the if/else-Bracktes from Spacebars do not change with it. I thought Session-Values are reactive...but maybe I have some sort of misconception how this works.
Try to write your helper as a function like so
'thevalue': function () {
return Session.get('thevalue');
}
See the docs here for more.
Session is reactive and helper is a reactive computation. The problem may be the format of your helper which should be like this:
thevalue: function(){
return Session.get('thevalue');
}
The problem could simply be that you are putting 'thevalue' in quotes and turning it in to a string where I believe it needs to run as a function.
Keep in mind if your 'thevalue' is 0 then your spacebars will return {{> two}}.
So I am trying use a helper as an argument of another helper in Spacebars. In the example below, 'getResultInfo' is a helper that gets data specific to the arguments passed, and 'formatResult' is a helper that formats its result and the results of other helpers.
<template name="example">
{{#each collectionResults}}
Label: {{formatResult getResultInfo this._id 'text'}}
{{/each}}
</template>
The issue I'm having is that Spacebars thinks that the arguments for 'getResultInfo' are the just second and third arguments for 'formatResult'. I'd really like to keep the helper's functions separate (ie. not having to format the result at the end of the 'getResultInfo' and every other helper that I have). Is there any alternate syntax or method of doing what I'm trying to achieve?
I think that you cannot chain two helpers with parameters on the second one like you did. Subsequent parameters will still be interpreted as parameters from the first helper.
I see two ways for solving this problem:
1) you could get rid of the parameters and use the data context provided by each.
each bind the data context to this so in getResultInfo you could just use this._id directly. But you have to remember that you need this data context each time you use this helper. And this pose a problem with the 'text' parameter which does not depend from the data context.
2) you could create a function corresponding to your getResultInfo helper and use it directly in the formatResult helper like this:
getResultHelper = function(id, text) {
//do what you want
};
//bind the function to your getResultInfo (example with a global helper)
Template.registerHelper('getResultInfo', getResultHelper);
//use the function in your template helper
Template.example.helpers({
formatResult: function(format) {
return getResultHelper(this._id, format);
}
});
//and finally your template
<template name="example">
{{#each collectionResults}}
Label: {{formatResult 'text'}}
{{/each}}
</template>
FYI, this is now possible in Meteor 1.2, via Spacebars sub expressions in Blaze.
<template name="example">
{{#each collectionResults}}
Label: {{formatResult (getResultInfo this._id 'text')}}
{{/each}}
</template>
I'm definitely missing something about the way Handlebars works. I need to call different partials depending on the value of a variable. Currently the only way I've found to do it is this:
<template name="base">
{{#if a}}{{> a}}{{/if}}
{{#if b}}{{> b}}{{/if}}
{{#if c}}{{> c}}{{/if}}
</template>
And in the corresponding JS:
Template.base.a = function () {
return (mode === "a");
}
Template.base.b = function () {
return (mode === "b");
}
Template.base.c = function () {
return (mode === "c");
}
...which strikes me as extremely verbose. What I'd really like to do is something like:
<template name="base">
{{> {{mode}} }}
</template>
In other words, the value of mode would be the name of the partial that is called.
This seems like it must be a very common use-case, but I can't find any examples of this online. Where have I gone wrong?
The partials are stored in Handlebars.partials so you can access them by hand in your own helper. There are a few tricky bits here though:
The contents of Handlebars.partials can be strings or functions so you have to compile the partials on first use.
Handlebars doesn't know if the partial will be text/plain or text/html so you'll need to call your helper in {{{...}}} or {{...}} as appropriate.
This stuff isn't exactly documented (at least not anywhere that I can find) so you have to reverse engineer the Handlebars source and fumble about with console.log(arguments) to figure out how to use Handlebars.partials.
You have to pass this by hand when you call the helper.
Fear not, it isn't really that complicated. Something simple like this:
Handlebars.registerHelper('partial', function(name, ctx, hash) {
var ps = Handlebars.partials;
if(typeof ps[name] !== 'function')
ps[name] = Handlebars.compile(ps[name]);
return ps[name](ctx, hash);
});
should do the trick. Then you can say:
{{{partial mode this}}}
and get on with more interesting things.
Demo: http://jsfiddle.net/ambiguous/YwNJ3/2/
Update for 2016: Version 3 of handlebars added Dynamic Partials. From the docs:
It's possible to dynamically select the partial to be executed by using sub expression syntax.
{{> (whichPartial) }}
Will evaluate whichPartial and then render the partial whose name is returned by this function.
Subexpressions do not resolve variables, so whichPartial must be a function. If a simple variable has the partial name, it's possible to resolve it via the lookup helper.
{{> (lookup . 'myVariable') }}