How to handle an IF STATEMENT in a Mustache template?
Solution 1
Mustache templates are, by design, very simple; the homepage even says:
Logic-less templates.
So the general approach is to do your logic in JavaScript and set a bunch of flags:
if(notified_type == "Friendship")
data.type_friendship = true;
else if(notified_type == "Other" && action == "invite")
data.type_other_invite = true;
//...
and then in your template:
{{#type_friendship}}
friendship...
{{/type_friendship}}
{{#type_other_invite}}
invite...
{{/type_other_invite}}
If you want some more advanced functionality but want to maintain most of Mustache's simplicity, you could look at Handlebars:
Handlebars provides the power necessary to let you build semantic templates effectively with no frustration.
Mustache templates are compatible with Handlebars, so you can take a Mustache template, import it into Handlebars, and start taking advantage of the extra Handlebars features.
Solution 2
Just took a look over the mustache docs and they support "inverted sections" in which they state
they (inverted sections) will be rendered if the key doesn't exist, is false, or is an empty list
http://mustache.github.io/mustache.5.html#Inverted-Sections
{{#value}}
value is true
{{/value}}
{{^value}}
value is false
{{/value}}
Solution 3
In general, you use the #
syntax:
{{#a_boolean}}
I only show up if the boolean was true.
{{/a_boolean}}
The goal is to move as much logic as possible out of the template (which makes sense).
Solution 4
I have a simple and generic hack to perform key/value if statement instead of boolean-only in mustache (and in an extremely readable fashion!) :
function buildOptions (object) {
var validTypes = ['string', 'number', 'boolean'];
var value;
var key;
for (key in object) {
value = object[key];
if (object.hasOwnProperty(key) && validTypes.indexOf(typeof value) !== -1) {
object[key + '=' + value] = true;
}
}
return object;
}
With this hack, an object like this:
var contact = {
"id": 1364,
"author_name": "Mr Nobody",
"notified_type": "friendship",
"action": "create"
};
Will look like this before transformation:
var contact = {
"id": 1364,
"id=1364": true,
"author_name": "Mr Nobody",
"author_name=Mr Nobody": true,
"notified_type": "friendship",
"notified_type=friendship": true,
"action": "create",
"action=create": true
};
And your mustache template will look like this:
{{#notified_type=friendship}}
friendship…
{{/notified_type=friendship}}
{{#notified_type=invite}}
invite…
{{/notified_type=invite}}
AnApprentice
working on Matter, a new way to gather professional feedback.
Updated on July 08, 2022Comments
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AnApprentice almost 2 years
I'm using mustache. I'm generating a list of notifications. A notification JSON object looks like:
[{"id":1364,"read":true,"author_id":30,"author_name":"Mr A","author_photo":"image.jpg","story":"wants to connect","notified_type":"Friendship","action":"create"}]
With mustache, how can I do a if statement or case statement based on the
notified_type
&action
...If
notified_type == "Friendship"
render ......If
notified_type == "Other && action == "invite"
render.....How does that work?
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SketchBookGames over 8 yearsthis bloats the mustache data, but is a usable and readable approach worth considering
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JeanValjean over 8 yearsThe equality example is really useful!
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Triforcey about 8 yearsGreat job on showing how to to if true, and doing false as well!
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SVSchmidt almost 5 yearsThis answer was actually better for me than the accepted one, as I wanted to use this in "automation for jira" plugin which uses mustache.
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Riccardo Manfrin over 3 yearsThis is THE answer guys
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Dexter Legaspi over 3 yearsthis answer is not wrong, but the correct/better answer is this one