How to access node field content in a custom module?

Question

I have a content type called districts and i have created the following fields

• district geojson(polygon values)
• harzards (list) - heavy rain, freezing rain, storm
• Alert level (list) - extreme, high, low

I am displaying in a view as a leaflet map. Now i would like to write a custom module that can get the field content of a nodes ie harzards and alert level and then pass them to a javascript file that will print specific colors to the districts in the view depending on the alert_level.

What is the best way to get the field content (harzards and alert_level) in to the custom module and then pass them to the javascript file? Or is there another way of achieving this. Thanks

Answer 1

Assuming you mean Drupal 7, just off the top of my head, implement something like hook_node_view() and attach the Javascript via the #attached element. I am frequently silly in my hook options, so someone may have a better one to suggest.

Answer 2

Not sure if what you need, but you can always load the node (the object of your content type) with:

$district = node_load($district_nid);

And then you have access to it's fields:

$harzard = $district->field_harzard['und'][0]['value];

The last line may change, depending on your language configuration.

OR as suggested by @Juraj Nemec, use Drupal's function to access fields:

$harzard = field_get_items('node', $district, 'field_harzard');

Answer 3

Why not continue using the same View that builds the leaflet map? Doing so seems simplest and most 'standard' in the Drupal world.

Three options (at least) come to mind for setting your styling if you stick with Views:

1. use the Views Conditional module.
2. rewrite the field_hazzard output to account for your conditions.
3. call the View in your custom module using views::getView.

Here's a step-by-step tutorial that accomplishes something similar using the 2nd option. It looks pretty good and broadly applicable: Conditional Formatting of Data In Drupal Views.