dojo/has!condition sometimes executes before dojoConfig processed

[bill]

dojo/_base/config.js parses that djConfig global variable, adding the specified has flags in a case like:

djConfig = {
   has : { "dojo-bidi" : true }
};

However, a module dependency like dojo/has!dojo-bidi?myModule can execute before the code in dojo/_base/config.js has executed, thus returning null instead of loading the specified module. Actually there's no guarantee that the code in dojo/_base/config will load at all. At least when using RequireJS as a loader; I haven't looked into what dojo.js does.

A workaround is to define all of our modules to explicitly load dojo/_base/config first:

require(["dojo/_base/config"], function(){
   define([
       ...
       "dojo/has!dojo-bidi?myModule",

However that's pretty onerous and I'm not sure if it would work with the builder.

[ben hockey]

is it naive to think that adding dojo/_base/config as a dependency to dojo/has will fix this? i haven't looked into it but it sounds like that would do it.

[Bryan Forbes]

dojo/_base/config already depends on dojo/has, so setting up the reverse dependency would give us a circular dependency.

[bill]

Right, it's a true circular dependency. I thought about just putting all the code from config.js into has.js, but config.js has a comment indicating that users may override the module in a build:

By defining user configuration as a module value, an entire configuration can be specified in a build, thereby eliminating the need for sniffing and or explicitly setting in the global variable dojoConfig. Also, when multiple instances of dojo exist in a single application, each will necessarily be located at an unique absolute module identifier as given by the package configuration. Implementing configuration as a module allows for specifying unique, per-instance configurations.

[bill]

Perhaps we should stop depending on dojoConfig altogether and instead use standard AMD module configuration setting. As documented on ​stack overflow (and probably other better places), we should be able to do something like:

var require = {
    config: {
         'dojo/has': {
              'dojo-bidi': true
         }
    }
};

The code in dojo/has.js is actually already setup to handle this. Unfortunately it's inside an if() block that doesn't normally execute:

if(!has("dojo-has-api")){
        ...
        cache = (module.config && module.config()) || {};

The code that runs instead is in dojo.js:

hasCache = has.cache = defaultConfig.hasCache;

Actually, I guess if we just fix dojo.js so that hasCache is populated from userConfig in addition to defaultConfig, things should start working.

[dylan]

Ticket planning... move current 1.13 tickets out to 1.15 to make it easier to move tickets into the 1.13 milestone.