consul/ui/packages/consul-ui/app/helpers/render-template.mdx

# render-template

`{{render-template 'template string' vars}}` is used to interpolate some dynamic
variables into a string and produce a string output as a result i.e. a micro,
regex based, template engine. For example:

```hbs preview-template
<figure>
  {{render-template 'http://localhost/?service={{Service.Name}}&datacenter={{Datacenter}}'
    (hash
      Datacenter="dc1"
      Service=(hash
        Name="Hello-Service"
      )
    )
  }}
  <figcaption>^ that is the rendered template</figcaption>
</figure>

```

Additionally the variables passed into the template are automatically URL
encoded as our primary usecase for this is for creating dynamic links/URLs. If
we ever need to reuse this without URL encoding, then an option could be added
as a named argument to disable/turn that off. In which case, encode should be
default and a knob provided to turn it off (at the time of writing our primary
usecase is to encode).

Currently supported separators are mustache style `{{VariableName}}`, although
we would like to add Javascript style `${VariableName}` separators in the future
and transition to default to those whilst remaining backwards compatible.
Mustache style are a documentated user 'feature' for some Consul config, so we
should be mindful of that.

**Please note:** Our `uri` helper (that is used extensively in the UI) also uses
some of the underlying functionality of `render-template` via our `encoder`
service.

## Positional Arguments

| Argument | Type | Default | Description |
| --- | --- | --- | --- |
| `template` | `String` |  | A template string for the variables to be interpolated into |
| `vars` | `Object` |  | An object/hash of variables to URL encode and interpolate into the template string |