---
layout: page
title: "JavaScript assert_options function"
comments: true
sharing: true
footer: true
alias:
- /functions/view/assert_options:832
- /functions/view/assert_options
- /functions/view/832
- /functions/assert_options:832
- /functions/832
---
<!-- Generated by Rakefile:build -->
A JavaScript equivalent of PHP's assert_options

{% codeblock info/assert_options.js lang:js https://raw.github.com/kvz/phpjs/master/functions/info/assert_options.js raw on github %}
function assert_options (what, value) {
  // From: http://phpjs.org/functions
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // *     example 1: assert_options('ASSERT_CALLBACK');
  // *     returns 1: null

  // BEGIN REDUNDANT
  this.php_js = this.php_js || {};
  this.php_js.ini = this.php_js.ini || {};
  this.php_js.assert_values = this.php_js.assert_values || {};
  // END REDUNDANT

  var ini, dflt;
  switch (what) {
  case 'ASSERT_ACTIVE':
    ini = 'assert.active';
    dflt = 1;
    break;
  case 'ASSERT_WARNING':
    ini = 'assert.warning';
    dflt = 1;
    throw 'We have not yet implemented warnings for us to throw in JavaScript (assert_options())';
  case 'ASSERT_BAIL':
    ini = 'assert.bail';
    dflt = 0;
    break;
  case 'ASSERT_QUIET_EVAL':
    ini = 'assert.quiet_eval';
    dflt = 0;
    break;
  case 'ASSERT_CALLBACK':
    ini = 'assert.callback';
    dflt = null;
    break;
  default:
    throw 'Improper type for assert_options()';
  }
  // I presume this is to be the most recent value, instead of the default value
  var originalValue = this.php_js.assert_values[ini] || (this.php_js.ini[ini] && this.php_js.ini[ini].local_value) || dflt;

  if (value) {
    this.php_js.assert_values[ini] = value; // We use 'ini' instead of 'what' as key to be more convenient for assert() to test for current value
  }
  return originalValue;
}
{% endcodeblock %}

 - [Raw function on GitHub](https://github.com/kvz/phpjs/blob/master/functions/info/assert_options.js)

Please note that php.js uses JavaScript objects as substitutes for PHP arrays, they are 
the closest match to this hashtable-like data structure. 

Please also note that php.js offers community built functions and goes by the 
[McDonald's Theory](https://medium.com/what-i-learned-building/9216e1c9da7d). We'll put online 
functions that are far from perfect, in the hopes to spark better contributions. 
Do you have one? Then please just: 

 - [Edit on GitHub](https://github.com/kvz/phpjs/edit/master/functions/info/assert_options.js)

### Example 1
This code
{% codeblock lang:js example %}
assert_options('ASSERT_CALLBACK');
{% endcodeblock %}

Should return
{% codeblock lang:js returns %}
null
{% endcodeblock %}


### Other PHP functions in the info extension
{% render_partial _includes/custom/info.html %}