jQuery validate (at least one field has text)

I have this page which has several TextAreas (asp.net mvc).

I need to开发者_如何学运维 validate that at least one of those fields has text in it. How can I do that with jQuery?

<%= Html.TextArea("taMetodologia",Model.Enmienda.Detalles.EnmiendaMetodologia, 8, 70,new {@class = "Especificaciones"}) %>

That's an example of the textAreas I have.

Assuming you are not using the validate plugin and all the textareas have the "Especificaciones" class, you could use a filter on the class.

If the length of the following is greater than 0, then at least one of the textareas had a value in it.

$(".Especificaciones").filter(function(){
    return $(this).val() != "";
}).length;

Check out this link as it should be what your looking for:

jQuery validation: Indicate that at least one element in a group is required

Quoted from the above link:

To start with, I put class="required_group" on each of the elements in the group. Then, I added a custom validation method:

jQuery.validator.addMethod('required_group', function(val, el) {
    var $module = $(el).parents('div.panel');
    return $module.find('.required_group:filled').length;
});

... a custom class rule to take advantage of the new method:

jQuery.validator.addClassRules('required_group', {
    'required_group' : true
});

... and finally a custom message for the new method:

jQuery.validator.messages.required_group = 'Please fill out at least one of these fields.';

Here is another link to someone that used this method but tweaked it:

jquery validation only one field in a group required