Bound conditional Handlebars helpers for Ember

if-all-exists.js

import ifConditionHelper from 'myapp/helpers/if-condition';

/**
 * Logical AND Existence Conditional Block
 *
 * Usage: {{#if-all-exists field1 field2}}Either field1 or field2 is truthy{{/if-all-exists}}
 *
 * Executes the given block if all arguments are defined
 */
export default function() {
  var options = arguments[arguments.length - 1];

  options.conditional = function(results) {
    return results.every(exists);
  };

  return ifConditionHelper.apply(this, arguments);
}

function exists(value) {
  return value !== undefined;
}

if-all.js

import ifConditionHelper from 'myapp/helpers/if-condition';

/**
 * Logical AND Conditional Block
 *
 * Usage: {{#if-all field1 field2}}Both field1 and field2 are truthy{{/if-all}}
 *
 * Executes the given block if all arguments are truthy
 */
export default function() {
  var options = arguments[arguments.length - 1];

  options.conditional = function(results) {
    return results.every(identity);
  };

  return ifConditionHelper.apply(this, arguments);
}

function identity(value) {
  return value;
}

if-any-exists.js

import ifConditionHelper from 'myapp/helpers/if-condition';

/**
 * Logical OR Existence Conditional Block
 *
 * Usage: {{#if-any-exists field1 field2}}Either field1 or field2 is truthy{{/if-any-exists}}
 *
 * Executes the given block if any argument is defined
 */
export default function() {
  var options = arguments[arguments.length - 1];

  options.conditional = function(results) {
    return results.any(exists);
  };

  return ifConditionHelper.apply(this, arguments);
}

function exists(value) {
  return value !== undefined;
}

if-any.js

import ifConditionHelper from 'myapp/helpers/if-condition';

/**
 * Logical OR Conditional Block
 *
 * Usage: {{#if-any field1 field2}}Either field1 or field2 is truthy{{/if-any}}
 *
 * Executes the given block if any argument is truthy
 */
export default function() {
  var options = arguments[arguments.length - 1];

  options.conditional = function(results) {
    return results.any(identity);
  };

  return ifConditionHelper.apply(this, arguments);
}

function identity(value) {
  return value;
}

if-condition.js

/**
 * Bound Conditional if/else Block
 *
 * Executes the given block if all arguments are equal
 * NOTE: this helper is meant to be used by other helpers by specifying
 * a callback as the `conditional` option
 */
export default function() {
  var args = [].slice.call(arguments);
  var options = args.pop();
  var context = (options.contexts && options.contexts[0]) || this;

  if (!options.conditional) {
    throw new Error("A conditional callback must be specified when using the if-condition helper");
  }

  // Gather all bound property names to pass in order to observe them
  var properties = options.types.reduce(function(results, type, index) {
    if (type === 'ID') {
      results.push(args[index]);
    }
    return results;
  }, []);

  // Resolve actual values for all params to pass to the conditional callback
  var normalizer = function() {
    return Ember.Handlebars.resolveParams(context, args, options);
  };

  // This effectively makes the helper a bound helper
  // NOTE: 'content' path is used so that multiple properties can be bound to using the `childProperties` argument,
  // however this means that it can only be used with a controller that proxies values to the 'content' property
  return Ember.Handlebars.bind.call(context, 'content', options, true, options.conditional, normalizer, properties);
}

if-equal.js

import ifConditionHelper from 'myapp/helpers/if-condition';

/**
 * Equality Comparison Conditional Block
 *
 * Usage: {{#if-equal field1 field2 "foo"}}field1 and field2 are equal to 'foo'{{/if-equal}}
 *
 * Executes the given block if all arguments are equal
 */
export default function() {
  var options = arguments[arguments.length - 1];

  // Find all unique values in the array; if one is left, they were all equal
  options.conditional = function(results) {
    return results.uniq().length === 1;
  };

  return ifConditionHelper.apply(this, arguments);
}

Thank you for publishing, this has been incredibly helpful for me! :)

Thank you so much for your help, these are awesome!

@slindberg - this is super helpful. any plans of porting these to an ember-cli addon?

Note: this doesn't seem to work with Ember >= 1.9 and Handlebars >= 2.0.0. It seems that resolveParams here no longer exists.

any word on this? I'm totally stuck trying to do something like {{#if has-permission "myPermission" }}.. the cli docs dont say how to do it, I get errors maybe due to handlebars 2.0.. no idea.. stuck

I'm getting this error in Ember 1.11

TypeError: Ember.default.Handlebars.bind is undefined