Handlebar if condition not working

问题:

Unable to use if condition in Handlbars template. Below is my jquery Handlebars function below,

$.each(data.response, function (i, item) {
   var source = $("#my-orders").html();
   var template = Handlebars.compile(source);
   html += template(item);
   //alert(html);
});
if(html){
   $("#myorderss").html(html);
}

When I'm using if condition, its not working.

{{#if id=='1'}}
{{/if}}

How to use if condition in handlebars template?

回答1:

This is a misunderstanding of the if condition. Look at the #if documentation here : http://handlebarsjs.com/builtin_helpers.html

You can use the if helper to conditionally render a block. If its argument returns false, undefined, null, "", 0, or [], Handlebars will not render the block.

What you need to do is a handlebar helper to test your condition.

Here is one example of a "test" helper that I use to do comparisons :

Handlebars.registerHelper('test', function(lvalue, operator, rvalue, options) {
    var doDisplay = false;
    var items = (""+rvalue).split("|");
    var arrayLength = items.length;
    for (var i = 0; (i < arrayLength); i++) {
        if (operator == "eq") {
            if (lvalue == items[i]) {
                doDisplay = true;
            }
        } else if (operator == "ne") {
            if (lvalue != items[i]) {
                doDisplay = true;
            }
        } else if (operator == "gt") {
            if (parseFloat(lvalue) > parseFloat(items[i])) {
                doDisplay = true;
            }
        } else if (operator == "lt") {
            if (parseFloat(lvalue) < parseFloat(items[i])) {
                doDisplay = true;
            }
        }else if (operator == "le") {
            if (parseFloat(lvalue) <= parseFloat(items[i])) {
                doDisplay = true;
            }
        }else if (operator == "ge") {
            if (parseFloat(lvalue) >= parseFloat(items[i])) {
                doDisplay = true;
            }
        }
    }
    if (doDisplay) {
        return options.fn(this);
    } else {
        return "";
    }
}); 

and here is how you call it for example if you and to test and display a result depending on the test:

{{#test id 'eq' '1'}}
{{id}} equals 1
{{/test}}
{{#test id 'ne' '1'}}
{{id}} do not equals 1
{{/test}}
{{#test id 'ge' '1'}}
{{id}} greater or equals 1
{{/test}}
{{#test id 'ne' '1'}}
{{id}} lower or equals 1
{{/test}}