different behaviors same application.

Gleisson Henrique

Hello everyone!

To be honest, I don't even know how to phrase this question properly. I am new to Oracle Apex and I love it so far. I am replacing an old Oracle Form legacy system with an app developed in Oracle Application Express 21.1.

For the running environment, I have two different scenarios. The first one is when my users are in the office. They access the app through running the latest Firefox version (currently 91.0.2) on their Windows 10 machine. The second scenario is when they are working remotely. Please don't ask me why but my IT Security Team provides a portal with a very restrict Citrix Enviroment for them to access. On this portal, they can run Firefox ESR 52.9.0, allegedly due to compatibility with other web based systems they keep this version up. The app that I am developing runs fine on the in office setup. Modal pages always popups, insert data form instances shows all the page items and etc. On the Citrix/older firefox version, it doesn't run properly at all. Modal dialog pages are not able to redirect to the pages they were called from, and some forms, when empty or to insert data form just shows up a blank page with no page item fields.

So I assumed it was due to the older version of Firefox and the citrix enviroment. It turns it isn't. I downloaded and installed the Summit Application ( https://apex.oracle.com/pls/apex/f?p=39731:1:4016291120747::::: ) and it runs fine on both scenarios. All the modal dialog pages pop up, blank insert forms have all the page items fields to input data and etc.

So I am assuming it is some configuration on my developed app.

I compared the properties of both apps, mine and the Summit Application app, to see if it was some configuration issue, theme settings or anything but I can not find any different settings. Even buttons look a little different between the two apps.

Here are some screen shots:

My app's home page running in scenario one:

My app's home page running in scenario two:

Note that frame (for lack of better term) with release version shows up halfway through the browser's page. Also, on the top right hand side corner the icons for login/logout and feedback are over each other.

Blank entry form on scenario one

Blank entry form on scenario two

Note how the buttons look and feel different between the same page on the different scenarios.

Lastly, the modal dialog page on scenario one:

the modal dialog page on scenario two:

Notice the entry form page comes up blank when it is a modal dialog page on scenario two.

I don't know what it could be. I tried checking the html and inspect the pages elements but it is a really time consuming task. And to be honest, for lack of experience, I am not sure if I know what I am looking for because the inspector shows no errors.

Any help is greatly appreciated!

fac586

What are the Universal Theme version numbers for the two applications?

This information is rather obscurely located:

• Go to Application > Shared Components > Theme
• Click Universal Theme - 42 link
• Scroll to the bottom of the page and the version number is at the end of the File Prefix property

fac586

If I change the property to #IMAGE_PREFIX#themes/theme_42/1.5/, it should fix and not break my app?

No, it won't. Changing that property alone will not perform a consistent and complete theme switch to the earlier Universal Theme version, nor would I recommend doing so.

The comparison of the theme versions was simply intended to confirm the nature of the problem, key to which are the APEX browser requirements documented in the Installation Guide:

Oracle Application Express requires a JavaScript-enabled browser and supports the current and prior major release of Google Chrome, Mozilla Firefox, Apple Safari, and Microsoft Edge.

That clearly does not include Firefox ESR 52.9.0, as the current and prior Firefox ESR releases are 91.0.1 and 78.13.0. Thus APEX 21.1 is not compatible with Firefox 52.9.0.

Under the covers, UT 21.1 is a major re-implementation of the APEX Universal Theme, and it seems that it is dependent on CSS and/or JavaScript features that are supported in the most recent Firefox versions, but not in 52.9.0.

Unfortunately, several APEX 21.1 components and features are directly dependent on UT 21.1, which is why I would not recommend attempting to downgrade the theme as a solution to the problem.

In my opinion the real problem lies in the provision of the outdated browser in the remote environment. Mozilla support for Firefox ESR 52.9.0 ended in September 2018: it has not received any security fixes for 3 years. It is baffling that an "IT Security Team" are currently mandating its use. They must have a very good explanation for this?

fac586

What are the Universal Theme version numbers for the two applications?

This information is rather obscurely located:

• Go to Application > Shared Components > Theme
• Click Universal Theme - 42 link
• Scroll to the bottom of the page and the version number is at the end of the File Prefix property

Gleisson Henrique

Hey @fac586 ,

Thanks for looking into my post. They are different.

The File Prefix property for my app is #IMAGE_PREFIX#themes/theme_42/21.1/

The File Prefix property for the Summit Application is #IMAGE_PREFIX#themes/theme_42/1.5/

If I change the property to #IMAGE_PREFIX#themes/theme_42/1.5/, it should fix and not break my app?

Gleisson Henrique

I changed the property to #IMAGE_PREFIX#themes/theme_42/1.5/ It did fixed the problem. However, I don't know exactly what the problem is. I will look into the documentation to try to figure it out. Thanks very much for your help!

fac586

If I change the property to #IMAGE_PREFIX#themes/theme_42/1.5/, it should fix and not break my app?

No, it won't. Changing that property alone will not perform a consistent and complete theme switch to the earlier Universal Theme version, nor would I recommend doing so.

The comparison of the theme versions was simply intended to confirm the nature of the problem, key to which are the APEX browser requirements documented in the Installation Guide:

Oracle Application Express requires a JavaScript-enabled browser and supports the current and prior major release of Google Chrome, Mozilla Firefox, Apple Safari, and Microsoft Edge.

That clearly does not include Firefox ESR 52.9.0, as the current and prior Firefox ESR releases are 91.0.1 and 78.13.0. Thus APEX 21.1 is not compatible with Firefox 52.9.0.

Under the covers, UT 21.1 is a major re-implementation of the APEX Universal Theme, and it seems that it is dependent on CSS and/or JavaScript features that are supported in the most recent Firefox versions, but not in 52.9.0.

Unfortunately, several APEX 21.1 components and features are directly dependent on UT 21.1, which is why I would not recommend attempting to downgrade the theme as a solution to the problem.

In my opinion the real problem lies in the provision of the outdated browser in the remote environment. Mozilla support for Firefox ESR 52.9.0 ended in September 2018: it has not received any security fixes for 3 years. It is baffling that an "IT Security Team" are currently mandating its use. They must have a very good explanation for this?

Gleisson Henrique

No, it won't. Changing that property alone will not perform a consistent and complete theme switch to the earlier Universal Theme version, nor would I recommend doing so.

I did change :) and you are right!!! While the change made everything work in the older firefox version. In the updated version of firefox, it is showing some minor visual glitches. Any field that's required shows "required" under the text box and all data pick field types are also off and the pop up calendar really small.

However, I wonder now how the Summit Application is running properly in the same Apex 21.1 environment being developed for an older version of the universal theme. Does Apex servers the theme older theme for backwards compatibility? Can I develop an app for the old Universal theme on 21.1?

It is baffling that an "IT Security Team" are currently mandating its use. They must have a very good explanation for this?

The Infrastructure guys are keeping the old version in place. They said it is a requirement. Apparently there is a web application that is so old that it is only compatible to that firefox version.

I did install older firefox versions to see which version the Universal theme would be. It worked on Firefox version 59, which is not that much newer than version 52.

thanks so much for your help and insights @fac586