al_get_next_config_entry with repeating values

al_get_next_config_entry with repeating values

Alianix

Member #10,518

December 2008

So I'm using al_get_next_config_entry to iterate through a config section however when it finds multiples of the same value it ends the section iteration:

#SelectExpand
  1int cfg_section_values( ALLEGRO_CONFIG *cfg, const char *section, const char *value){
  2
  3    const char *str = NULL;
  4    ALLEGRO_CONFIG_ENTRY *iter = NULL;
  5    int n = 0;
  6
  7    if( !(str = al_get_first_config_entry( cfg, section, &iter))){
  8        printf("ERROR: No such section [%s] while searcing for [%s]!\n", section, value);
  9        return( -1);
 10    }
 11
 12    if( !strcmp( str, value)) n++;
 13
 14    while( (str = al_get_next_config_entry( &iter))){
 15
 16        printf("%s\n", str);
 17        if( !strcmp( str, value)) n++;
 18
 19    }
 20
 21    printf("Found %d [%s] value in section [%s]\n", n, value, section);
 22
 23    return( n);
 24}

I have this in my config file:

[GAME]
#--------------------------------------------------------------------------------
DATA-PATH = data
FONT-PATH = font
GFX-FLAGS = WINDOWED
#GFX-FLAGS = FULLSCREEN
GFX-OPTION = VSYNC
TIMER-FREQ = 24
#SYS-FONT = bgothl.ttf,12
SYS-FONT = pirulen.ttf,12
ANI-SET = Animations.ani
BMP-SET = snow.ani
FONT = bgothl.ttf,12
FONT = pirulen.ttf,12
#--------------------------------------------------------------------------------

However it only finds one FONT value instead of two. Is this normal?

J-Gamer

Member #12,491

January 2011

That is indeed expected behaviour, because you would otherwise have to find a way to make one key have multiple values. ie: if you look up the value of font, what should it be?
ie: what should al_get_config_value(cfg, "Game", "FONT") return? undefined if you have multiple entries for the same key.

" There are plenty of wonderful ideas in The Bible, but God isn't one of them." - Derezo
"If your body was a business, thought would be like micro-management and emotions would be like macro-management. If you primarily live your life with emotions, then you are prone to error on the details. If you over-think things all the time you tend to lose scope of priorities." - Mark Oates

Alianix

Member #10,518

December 2008

I disagree, it could return the first value found. There are good reasons to have multiple entries of the same name.

J-Gamer

Member #12,491

January 2011

Alianix said:

There are good reasons to have multiple entries of the same name.

Which are?

Anyway, it is impossible to specify which of the double entries you want to get with al_get_config_value, just like an std::map.

Append:
I haven't ever used the allegro config routines, so I don't know which element al_get_config_value will return. I figure it'll be either the first or the last entry, depending on how it the routines were written(overwriting the value at each read, or check if the element already exists,...).

SiegeLord

Member #7,827

October 2006

The Manual said:

Keys do not need to be unique, but all but the last one are ignored.

"For in much wisdom is much grief: and he that increases knowledge increases sorrow."-Ecclesiastes 1:18
[SiegeLord's Abode][Codes]:[DAllegro5]:[RustAllegro]

Alianix

Member #10,518

December 2008

The fact that we are not sure which entry we get when multiples are found suggest that something is perhaps missing. Otherwise having multiple fonts is perfectly natural and would make sense to be able to load them all by iterating through the config entries. This makes sense to me from a programming point of view also. If you have a loading class it would need to find matching entries to know which loader to call for example. I guess I could use prefixes FONT_ and strstr instead but i don't see a good reason for this other than getting around the issue at hand.

Arthur Kalliokoski

Second in Command

February 2005

Quote:

all but the last one are ignored.

They all watch too much MSNBC... they get ideas.

Alianix

Member #10,518

December 2008

Ok got it, so how do i count them? Or get intermediate entries? I doesn't sound like this behavior is making much sense.

SiegeLord

Member #7,827

October 2006

Alianix said:

Ok got it, so how do i count them? Or get intermediate entries?

Impossible. You'll need to either use different keys (font0, font1), separate multiple fonts by delimeters, or use a different configuration file format. Not many configuration file formats support duplicate keys like that, incidentally... XML is the most popular one I can think ok. Everything else forces you to use lists (like JSON/YAML).

"For in much wisdom is much grief: and he that increases knowledge increases sorrow."-Ecclesiastes 1:18
[SiegeLord's Abode][Codes]:[DAllegro5]:[RustAllegro]

Elias

Member #358

May 2000

XML isn't a configuration file format though, just a markup language. If you use actual keys by attaching id attributes to elements they must be unique as well.

--
"Either help out or stop whining" - Evert

Alianix

Member #10,518

December 2008

Ok I'm not going to make a fuss out of this, probably just using FONT_XXX will do, then I will use strstr or strncmp...Thanks for your help!

SiegeLord

Member #7,827

October 2006

Elias said:

XML isn't a configuration file format though, just a markup language.

A markup language that's nearly never used for markup purposes .

"For in much wisdom is much grief: and he that increases knowledge increases sorrow."-Ecclesiastes 1:18
[SiegeLord's Abode][Codes]:[DAllegro5]:[RustAllegro]