always in the process of learning Javascript and modifying a cool autocomplete library, i am now in front of this :
i need to check if something passed in an object literal is a variable/field (that is to be considered as a simple value) or is something that can be called.
(as MY autocomplete depend on many input fields, i need to "value" the right things, just before the Ajax.Request) so that this declaration (see the 'extra' parts...)
myAutoComplete = new Autocomplete('query', {
serviceUrl:'autoComplete.rails',
minChars:3,
maxHeight:400,
width:300,
deferRequestBy:100,
// callback function:
onSelect: function(value, data){
alert('You selected: ' + value + ', ' + data);
}
// the lines below are the extra part that i add to the library
// an optional parameter, that will handle others arguments to pass
// if needed, these must be value-ed just before the Ajax Request...
, extraParametersForAjaxRequest : {
myExtraID : function() { return document.getElementById('myExtraID').value; }
}
see the "1 // here i'm lost..." below, and instead of 1 => i would like to check, if extraParametersForAjaxRequest[x] is callable or not, and call it if so, keeping only its value if not. So that, i get the right value of my other inputs... while keeping a really generic approach and clean modification of this library...
{
var ajaxOptions = {
parameters: { query: this.currentValue , },
onComplete: this.processResponse.bind(this),
method: 'get'
};
if (this.options.hasOwnProperty('extraParametersForAjaxRequest'))
{
for (var x in this.options.extraParametersForAjaxRequest)
{
ajaxOptions.parameters[x] = 1 // here i'm lost...
}
}
new Ajax.Request(this.serviceUrl, ajaxOptions );
You can do a typeof to see if the parameter is a function, and call it if it is.
var value;
for (var x in this.options.extraParametersForAjaxRequest)
{
value = this.options.extraParametersForAjaxRequest[x];
if (typeof(value) == 'function') {
ajaxOptions.parameters[x] = value();
}
else {
ajaxOptions.parameters[x] = value;
}
}