Timber get_theme_mod in template - twig

Question

I'm very beginner with Timber.
I want to redo (reproduce) one of my wordpress themes with Timber.
I try to call a theme_mod in my template but nothing is showing up.
Any answer or advise would be appréciate.
My original wp header.php
//***********************************Phone******************************************************//
$idbbase_very_top_header_phone = get_theme_mod( 'idbbase_very_top_header_phone', esc_html__( '(+9) 0999.500.400', 'idweb' ) );
$idbbase_very_top_header_phone = apply_filters( 'idbbase_translate_single_string', $idbbase_very_top_header_phone, 'Very Top Header' );
$idbbase_very_top_header_phone_text = get_theme_mod( 'idbbase_very_top_header_phone_text', esc_html__( 'Call us: ', 'idweb' ) );
$idbbase_very_top_header_phone_text = apply_filters( 'idbbase_translate_single_string', $idbbase_very_top_header_phone_text, 'Very Top Header' );
if ( ! empty( $idbbase_very_top_header_phone ) || ! empty( $idbbase_very_top_header_phone_text ) ) {
echo '<div class='.$class.'><i class="fa fa-phone"></i>';
echo '<span><strong class="idbbase_very_top_header_phone_text">';
echo $idbbase_very_top_header_phone_text.'</strong>';
echo '<p class="idbbase_very_top">' .wp_kses( $idbbase_very_top_header_phone, 'post', $allowed_protocols ) . '</p></span>';
echo '</div>';
} elseif ( isset( $wp_customize ) ) {
echo '<div id="idbbase_very_top_header_phone" class="idbbase_only_customizer '.$class.'"><span><strong>'.$idbbase_very_top_header_phone_text.'</strong><p class="idbbase_very_top_header_phone_text">' .wp_kses( $idbbase_very_top_header_phone, 'post', $allowed_protocols ) . '</p></span></div>';
}
My Timber header.php
//*************Phone******************************************************//
$idagency_very_top_header_phone = get_theme_mod(
'idagency_very_top_header_phone', esc_html__( '(+9) 0999.500.400', 'idweb' )
);
$idagency_very_top_header_phone2 = apply_filters(
'idagency_translate_single_string', $idagency_very_top_header_phone, 'Very
Top Header' );
$idagency_very_top_header_phone_text = get_theme_mod(
'idagency_very_top_header_phone_text', esc_html__( 'Call us: ', 'idweb' ) );
$idagency_very_top_header_phone_text2 = apply_filters(
'idagency_translate_single_string', $idagency_very_top_header_phone_text,
'Very Top Header' );
$context['idagency_very_top_header_phone'] =
$idagency_very_top_header_phone;
$context['idagency_very_top_header_phone'] =
$idagency_very_top_header_phone2;
$context['idagency_very_top_header_phone_text'] =
$idagency_very_top_header_phone_text;
$context['idagency_very_top_header_phone_text'] =
$idagency_very_top_header_phone_text2;
$GLOBALS['timberContext'] = Timber::get_context();
ob_start();
Timber::render( 'base.twig', $context );
My base.twig
{% if idbbase_very_top_header_phone %}
<div class="col-md-3">
<a href="#">
<i class="fa fa-phone"></i>
</a>
<span>
<strong>{{ idbbase_very_top_header_phone_text }}</strong>
<p>{{ idbbase_very_top_header_phone }}</p>
</span>
</div>
{% endif %}

Answer 1

Timber's philosophy of separating data from markup requires a significant conceptual shift when compared to the standard Wordpress template architecture.
The root of your problem is that you are treating your header like a template when it is actually a partial.
In Timber terms, a template corresponds to a post or an archive and consists of two files:
A Twig file with your html markup mixed with some variables and logic, and a PHP file that, at minimum, defines the following:
The Timber context for a given post generated with Timber::context() (formerly get_context(), which has been deprecated)
Which twig file (or files) should be used to render the template
The very simplest Timber PHP template file could look like this:
<?php
/*
* This is the `single.php` template
*/
$context = Timber::context();
Timber::render( 'single.twig', $context );
This would generate the rendered contents of single.twig along with some global context values. In order to pass real values to the template, you have to assign them to $context, as you have attempted to do with $context['idagency_very_top_header_phone'], etc. However, these values cannot be assigned at the level of a partial — they must be assigned at the template level or higher.
To do what you are trying to do, you're going to need to set up a template (e.g. single.php and single.twig), and then include the header.twig file inside your template Twig file using {% include 'header.twig' %}.
Then you need to define your context values so that they are available to single.twig and all of its included partials, which in this case would include header.twig. You can define these directly inside the single.php file, after $context is defined. For simplicity, I'm only defining one of your values:
/* single.php */
$context = Timber::context();
$idagency_very_top_header_phone = get_theme_mod(
'idagency_very_top_header_phone',
esc_html__( '(+9) 0999.500.400', 'idweb')
);
$context['idagency_very_top_header_phone'] = $idagency_very_top_header_phone;
Timber::render( 'single.twig', $context );
If you need these values to be global across all templates, you can also define them in your theme's functions.php using the (poorly documented) timber/context filter. Then the values will be available in any template where that Timber::context() is used:
/* This would be placed in your functions.php file
* (or a separate file that's been included in functions.php)
*/
add_filter( 'timber/context', function( $context ) {
$idagency_very_top_header_phone = get_theme_mod(
'idagency_very_top_header_phone',
esc_html__( '(+9) 0999.500.400', 'idweb')
);
$context['idagency_very_top_header_phone'] = $idagency_very_top_header_phone;
return $context;
} );
This leaves out some key steps for setting up a full template, like including the data from the actual post, but that is all decently documented in Timber's Getting Started guide.
The key, TL;DR points are:
The Timber context is defined once per post
The context and all of its values are passed directly from the post's PHP template to its Twig template
Twig partials are not tied directly to partial-specific PHP files.
Partials included within a Twig template inherit the Timber context from that template. The same goes for partials nested within those partials.

Answer 2

This is late, but for any future dwellers, the above answers only show how to do it the WordPress way in timber, whereas, there's a simpler native way to achieve this in timber.
This is how you can get any current theme mod in timber twig view files natively:
{{ site.theme.theme_mod('mod_name_here') }}
How it works: Timber supplies the current theme object in the default global object (you don't need to add this manually, anywhere).
From Timber's documentation (here), timber theme object has this method: theme_mod
Hope this helps anyone stuck in future.