Handlebars - Concat string parameters when calling

问题:

I would like to know if it is possible to concat a variable with another string when loading a partial using Handlebars.

{{partial logos this ns=../ns nsr=../nsr id=id+"something"}}

I'd like to concat id+"something" and storing it into id, which would be sent to the template.

I'm using a custom helper to load partials (partial) which merge this with the options.hash provided by handlebars.

回答1:

There is a way actually. I've tried with default partial loader ">", but I hope it should work with "partial" too.

You can write a helper like this

Handlebars.registerHelper( 'concat', function(path) {
    return "/etc/path" + path;
});

and Call it like

{{> responsive-image src=(concat '/img/item-tire.png') alt="logo" }}

I hope that helps.

回答2:

Here's an easier way. A helper named 'concat':

module.exports = function(){
  var arg = Array.prototype.slice.call(arguments,0);
  arg.pop();
  return arg.join('');
};

To be used as:

{{>myPartial id=(concat "foo" myVar myOtherVar)}}

回答3:

You could do a slightly more reusable solution like so:

module.exports = function (json) {
  var concat = '';
  var flipArray = [];
  for(var key in json.hash){
    flipArray.push(json.hash[key]);
  }

  for(var i = (flipArray.length - 1); i >= 0; i--){
    concat += flipArray[i];
  }

  return concat;
};

Then call it like so:

{{> icon name=(concat a="file-" b="pdf")}} // passes file-pdf to the partial under the hash value name

or

{{concat a="icon-" b="pdf" c="-Asdfasd" d="zxcvzxcvzxcvxz"}} // outputs icon-pdf-Asdfasdzxcvzxcvzxcvxz

The reason for the looping backwards in the helper is because handlebars currently lists it's hash parameters from last to first from the order you declare them.

回答4:

No, this is not possible. Use concatenation inside your helper.

{{partial logos this ns=../ns nsr=../nsr idKey=id idValue="something"}}

回答5:

Try following. Link helper is my own helper for adding context path /us

Handlebars.registerHelper('link', function(option,parameter) {
            return '/us' + option.hash.target;
        });

Handlebars.registerHelper('concat', function() {
            var outStr = '';
            for(var arg in arguments){
                if(typeof arguments[arg]!='object'){
                    outStr += arguments[arg];
                }
            }
            return outStr;
        });

Then I have called like this. My url having puppies

{{link target=(concat '/' url)}}

Then finally i got output like this /us/puppies

回答6:

If you're doing a simple a + b concatenation and you're already including handlebars-helpers, you can use the add helper:

{{> myPartial myVariable=(add someVariable "some string") }}

回答7:

In ES6 this is possible using this helper: concat : (...strs) => strs.join('')

You may also want to skip parameters given by Handlebars, which is: concat : (...strs) => strs.filter( arg => typeof arg !== 'object' ).join('')