Pebble templating for YAML file

Question

I am trying out Pebble templating for a config file which is in YAML format. The value for this comes from another YAML file. That is -

1. value.yml contains:-

    server:
     -
      box1:
        host:"12345"

2. config.yml contains:-

    server:
      -
       env: "abc"
       host: {{ server.box1.host }} 

I could read the config.yml as string and create a Pebble template. Using evaluate I am able to replace the template with context variable whose name is not nested (example {{ serverBox1Host }} --> this works).

If I use {{ server.box1.host }}, I get com.mitchellbosecke.pebble.error.RootAttributeNotFoundException: Root attribute [server] does not exist or can not be accessed and strict variables is set to true. If I set strictVariables as false, the {{ server.box1.host }} is replaced with empty.

How to solve this?

context.put("server.box1.host", "suriya" );

I took references from: https://www.programcreek.com/java-api-examples/?api=com.mitchellbosecke.pebble.PebbleEngine

I am using "String Template":

new PebbleEngine.Builder()
                .strictVariables(true)
                .newLineTrimming(false)
                .loader(new StringLoader())
                .build();

Thanks

Answer 1

You can use the dot (.) notation to access attributes of variables that are objects. If the attribute contains any atypical characters, you can use the subscript notation ([]) instead.

{{ foo.bar }}
{{ foo["bar"] }}

Behind the scenes foo.bar will attempt the following techniques to to access the bar attribute of the foo variable:

If foo is a Map,

foo.get("bar")
foo.getBar()
foo.isBar()
foo.hasBar()
foo.bar()
foo.bar

Additionally, if foo is a List, then foo[0] can be used instead of foo.get(0).

You can take a look at pebble documentation here : https://pebbletemplates.io/wiki/guide/basic-usage/

Answer 2

Resolved this:

Variable name assigned in the context was server like - context.put("server", new HashMap<String, Object> map1);

And map1 had nested map whose keys was box1 and host. The value of the host was suriya.

map1 :
key - box1
value - Map with key host and value suriya.

In the Pebble template was able to access {{ server.box1.host }} and this rendered with value "suriya"