metaprogramming - Can a ruby object call super on a "grandparent"? -


if have class salad method chew , use super in it, call next available chew method available going chain of ancestors. if want "reach 2 levels up" (to second available chew method going chain)? there way without adding super first ancestor's method?

to make little more concrete, suppose salad class, salad object:

class salad < food   include almonds   include gorgonzola   include spinach   include dressing    def chew     super   end end  salad = salad.new

the array of ancestors this:

[salad, dressing, spinach, gorgonzola, almonds, food, object, kernel, basicobject]

if want salad.chew trigger chew method in spinach without adding super dressing#chew, possible? there way reach 2 levels (in same way super "reaches" 1 level up)?

yes, there way describing, , way through methods #method , #instance_method, in method = spinach.instance_method( :chew ), can bind salad, or metaclasses of salad instances, in method.bind( salad ). mechanism not neat using convenience keyword super, offers superset of super's functionality. there few more details, trust me, way, can want. that's power of ruby – can anything, point lispiest magic, need ripper, , (the far unfinished) sorcerer.

(for usage example, see other answer @ using object.inspect / object.to_s on class derived hash)


Comments

Post a Comment

Popular posts from this blog

SPSS keyboard combination alters encoding -

my question not have programming practical issue on spss. accident keyword combination cannot remember because did not intend press changed encoding in spss , text in data in different language english shown small boxes. nevertheless, when kind of analysis performed different language text shown in output. does know reason? tried change encoding did not produce result. first, @ edit > options , see whether setting unicode or locale. might fix it. if have text in multiple languages, want unicode. otherwise, may have specific locale set wrong. can change set locale, need know locale want use.
Read more

Add new record to the table by click on the button in Microsoft Access -

in ms access form want implement separate button, adds new record table. in order added button , attached button event: private sub btnaddrec_click() refresh codecontextobject on error resume next docmd.gotorecord , , acnewrec if err.number <> 0 btnaddrec.enabled = false end if end end sub everything ok when open window , click btnaddrec button, problem when first of perform navigation through existed records , after click on button. got runtime error: 2105: «you can't go specified record. may @ end of recordset» . how solve issue, need have ability add new record on click on specific button, no matter, have walked or not walked through records before. thanks. i created simple form field call description (and autonumber) , created button code follows click event. filled number of records , navigated through them, clicked addnewrec button. form navigated new record without issues. able click addnewrec button directly after
Read more

javascript - jQuery .height() return 0 when visible but non-0 when hidden -

i have problem here right opposite others: in jquery cannot height of element when it's visible, when hidden. have html code: <div id="filtering-filter-holder"> <div id="filtering-filter-holder-inner"></div> </div> basic css it: #filtering-filter-holder { display: none; position: absolute; width: 420px; min-height: 100px; padding: 5px 5px 5px 5px; background-color: #ffffff; border: 1px solid #164372; } and finally, js in document.ready(): $('div.filtering-filter-headline').mouseenter(function() { var el = $(this).parent().find('div.filtering-filter-content'); if ($('div#filtering-filter-holder').is(':visible')) { $('div#filtering-filter-holder-inner').stop(true, true).fadeout(300, function() { $('div#filtering-filter-holder-inner').html($(el).html()); var height = $('div#filtering-filter-holder-inner&#
Read more