[Closed] How to Change a Setting in Firefox, Without Using the GUI

[Zohar]

Hi

 

If you open Firefox, and enter in the URL Field:  about:config

You will see many settings that you can edit.

 

One of them for example is:

gfx.downloadable_fonts.enabled

This is a boolean setting that tells firefox whether to download custom fonts that a website want the browser to download, or not.

 

How can I change this setting programmatically, without automating the GUI?

 

So I can turn this setting On and Off, without seeing the GUI for the settings all the time...

 

I hope it's pssible

 

Thank you

Edited July 23, 2017 by Zohar

[ViciousXUSMC]

I do not have FF installed on this computer but the settings are usually in the registry or in a settings file.

I just do a compare before/after the change to see what changed and then script it.

 

https://support.mozilla.org/en-US/questions/965842

[mdwerne]

I've found most of the settings I need to change are in the prefs.js file in each Firefox users profile.

I've had great success with this script: https://www.autoitscript.com/forum/topic/169753-firefox-configuration

Hope this helps,

-Mike

Update: Using the above script, this command allowed me to change from true to false...I assume the method to toggle back is obvious. 

_FF_Config("gfx.downloadable_fonts.enabled", false)

Make sure you quit Firefox before attempting to make the change.

Edited October 16, 2015 by mdwerne
Adding solution...

[Zohar]

Hi ViciousXUSMC and mdwerne

 

Thank you both for this solution,

it will indeed work, and it's indeed programmatic and not via GUI,

however since it messes with the config file, it is a disadvantage,

since if the user changes other settings via the GUI, then they will be overridden by the file that we write.

(that's why it's emphasized in the _FF_Config() function to close Firefox first..)

 

Anther disadvantage of messing with the config file, is that the change will only happen after firefox is opened again.

 

For these reasons,I am looking for a programmatic way which uses some Object Model that Firefox provides (hopefully),

and which allows changing a setting..

.

Is there a chance that there is some?

 

[BrewManNH]

The pref.js file IS the programmatic way to configure FireFox. You only have to do it once, and before FF is opened. You could do it by including it in the StartUp folder to have it run on log in.

The changes a user makes to FF that shows in about:config should be in one of the prefs.js files and your script can read these files prior to writing to them to make sure you're not changing a user setting.

[Zohar]

Thank you BrewManNH,

but as I asked in the last post, If there is an Object Model that we can use,

it will be a better method of achieving it.

 

I do hope Firefox exposed an Object Model..

[pcjunki]

you could set it globally in Mozilla.cfg
which is stored in the same directory as firefox.exe

just add this line, and it's set for all users

pref("gfx.downloadable_fonts.enabled", false);
 

[ViciousXUSMC]

Also the link I gave shows how to lock preferences and have user.js set preferences at startup so no need to have issues with closing FF first.  

You really have quite a few options here, all of them quite valid and easy to implement. 

[Zohar]

pcjunki,

but I don't want just to set uit once and for all..

I want to be able to togle it on and off when ever needed.

(usually it's off, and on some occasions I want to temporarily turn it on).

 

BTW,

maybe there's a way to change Firefox's settings via command line?

 

It's amazing how little firefox did, regarding automation for the browser..

 

For example, to automate webpages, one needs to install the MozRepl add-in..

You would expect that such a feature would be available built-in..

I like Firefox, but in terms of automation it's extremely disappointing

Edited October 16, 2015 by Zohar

[pcjunki]

you can toggle it on off,

pref("gfx.downloadable_fonts.enabled", false);

or

pref("gfx.downloadable_fonts.enabled", true);

[Zohar]

yes I know

but using what you said (setting it globally in Mozilla.cfg file) still has the disadvantages that I wrote earlier..

[BrewManNH]

Have you tried modifying the prefs.js or mozilla.cfg file while FF was running? Does it change anything you're trying to change?

[JohnOne]

Seems to me like you're not interested in anything anyone has to say, I'm wondering why your question was not just "Does FF expose COM methods?"

It does not, there would be a UDF that uses it easily found if it did.

For example, to automate webpages, one needs to install the MozRepl add-in

So why not just do that?

[jguinch]

@Zohar : applying changes in prefs.js or mozilla.cfg seems to be the only way to change the Firefox configuration. You can edit mozilla.cfg even if Firefox is open, but all changes require a restart of the application to be applied.

 

[Zohar]

Seems to me like you're not interested in anything anyone has to say, I'm wondering why your question was not just "Does FF expose COM methods?"

I am very much interested in what everyone has to say,

but not all solutions will fit..

Not choosing a solution doesn't mean I am not interested in what people have to say..

 

    It does not, there would be a UDF that uses it easily found if it did.

Yeah, I begin to understand there isn't another way..

Sad

 

@Zohar : applying changes in prefs.js or mozilla.cfg seems to be the only way to change the Firefox configuration.

You can edit mozilla.cfg even if Firefox is open, but all changes require a restart of the application to be applied.

Thank you jguinch,

Since it's the only way, then I will use it, and close FF before changing anything..

 

Thank you