Internals

This section describes some of the internal operation of moe-js

The Context Object

In addition to the .model object that is used to pass data to a template, there is a second special object called the .context. Unlike the model object which can change between templates and partials, the context object remains the same across all templates used.

The context object is optional and if used should be passed as the second parameter to the compiled template function (see example below)

Partial Template Resolution and Model Decoration Hooks

By default when a partial template is referenced, the file is loaded directly from the current directory. Since most integrations will want to look for partials in a particular location, the context object can contain a special $moe member variable that can provide functions used to resolve the partial location and to decorate the partials model object before the partial is rendered.

These hooks are used by Moe-js's Express integration to look for partials in the views subfolder and to merge models with local settings.

Each function can be supplied in a Sync and optionally an Async version. The async versions will only be called if the template was compiled as an async template and if not present the sync version will be used as a fallback.

let context = 
{
    // Special member '$moe' provides hooks for partial processing
    $moe: 
    {
        // Map a partial name to an actual file path    
        resolvePartialPath: function(partialTemplateName) {
            // Return the full path to the template file to use
            return path.join("./views/partialViews", partialTemplateName);
        },

        resolvePartialPathAsync: async function(partialTemplteName) {
            // Async version of above.  Only called on async templates
            // and will fall back to sync version if not present
        },

        // Provides an opportunity to "decorate" the a model object before it's
        // passed to a partial.
        decoratePartialModel: function(model) {
            // Return either the original object modified, or a new object
            // merged with the original model.
            return merge({
                "someCustomSettingsForThePartial": "Whatever",
                "somethingElse": 99
            }, model);
        },

        decoratePartialModelAsync: async function(model) {
            // Async version of above.  Only called on async templates
            // and will fall back to sync version if not present
        },
    }  
};

let template = moe.compile(templateText);
let model = { }
let text = template(mode, context);     // NB: passing the context object