Is it possible to assign a parameter value within handlebars templates without using helpers?

问题

I am trying to assign values within a template, the idea is to do something like this:

    {{#if author}}
        {{className = 'classA'}}  <- trying to implement this line.
    {{else}}
        {{className = 'classB'}}
    {{/if}}

<div class={{className}}></div>

Is it possible to do so without registerHelper?

回答1:

You can do this with a partial.

partial:

<div class="{{classname}}">{{var1.author}}</div>

template:

{{#if author}}
{{> mypartial var1=. classname="classA"}}
{{else}}
{{> mypartial var1=. classname="classB"}}
{{/if}}

In this example I've passed the current scope as var1. I can't recall if the scope stays the same and the new variable is just added to it or if you have to pass the scope manually.

回答2:

I needed this solution solved in the same way the original poster expected. Therefore I created a helper function to do this for me.

function setVariable(varName, varValue, options){
  options.data.root[varName] = varValue;
};

Contained within the options in the helper, is the data block, with the root of the helper variables.

I placed my variable within the root object, either assigning or overwriting with the value provided.

The helper in html looks a lot like this.

{{setVariable "thisVar" "Contents Here"}}

<div>
  {{thisVar}}
</div>

回答3:

Small update from a helpful above answer. In Handlebars 4.x, it seems we have to get the variables from @root.

handlebars.registerHelper('assign', function (varName, varValue, options) {
    if (!options.data.root) {
        options.data.root = {};
    }
    options.data.root[varName] = varValue;
});

And then,

{{assign 'imageTag' 'drop-155'}}

{{@root.imageTag}}

回答4:

 {{#if author}}
       <div class='{{ classA }}'></div>
    {{else}}
        <div class='{{ classB }}'></div>
    {{/if}}

or try

<div class='{{#if author}} {{ classA }} {{else}} {{ classB }} {{/if}}'></div>

or maybe this

create a script

<script> 
  $(function(){
       var class;
       {{#if author}}
          class = {{ classA }}
       {{else}}
          class = {{ classB }}
       {{/if}}

   var $specials = $('.special');
   $specials.removeClass('special');
   $specials.addClass(class);
  })

</script>

来源：https://stackoverflow.com/questions/24736938/is-it-possible-to-assign-a-parameter-value-within-handlebars-templates-without-u

标签

handlebars.js