Why in design time it does not show the html preview in my form?

Hi, as per the subject, i attached my screen shots

  1. in chrome browser , when it running properly, it showed up as follow,

  2. and then in my VSC, the HTML code that showed above, are ,

  3. but in my VSC, the editor there, the design Form just won't load the html, as shown,

is there anyone know, what is the reasons ?

Would be possible to .zip your project and send it to me at jose.leon@tmssoftware.com?


I have been investigating this one. The template is raising a javascript error when loaded into the designer, presumably because it does require the js environment to match something very specific. I keep investigating and will let you know when I found the exact problem.

One of the issues is that some of the scripts you are using (framework7) are not validating properly some variables for undefined values, and because of the environment the templates are loaded is not exactly a web browser, that is causing the error. Fixing that issue on the framework also shows that the template is making heavy use of javascript, not only for rendering, but also for loading the pages using xmlhttprequest, and such requests cannot be processed inside the designer. Because that could be a potential security issue.
While the solution I guess is not ideal for you, I suggest you to split the template in pieces, and just use the one for the border area (the one with the menus) and isolate the other pages on each TMS Web Core form, because TMS Web Core already provides the mechanism to load pages using xmlhttprequest, so they will collide.


Hi Jose,
Thanks for taking time to explore and advice, let me clarify from you,

  1. Will you be able to point me out how to see or debug the error you mentioned "...framework is using heavy use if JS,loading page using XMLHttpRequest that caused some variables undefined and cannot be processed by designer ..." ? (i wish to study it myself)

  2. With you suggestions, I would like to find out is the following what u meant ?

    • 2.1. I will need to use only the main.html that load the page.html template in the page folder, combine them into one and make it as the default main page? is that correct?

    • 2.2. Do I need to move as per some of the suggestions I saw in some video tutorial, that Javascript library is best to move to the index.HTML ?

    • 2.3. When splitting the page, you are suggesting that i will need to split the template into pieces, which I thought my pages already in pieces, because it already was in <<"template">> tag for each of the html page in the [pages] folder. So are you saying that I need to remake them into a proper HTML page and make it become a COMPATIBLE TMS Webcore form ?

    • 2.4. for handling cases like this kind JS framework, if i were to consider to develop it using Delphi component to handle that, will that possible and you can point me to some direction of how to go about it ? ( reasons of my team has been spending a considerable amount of time in this framework7 and personally i do like the way it does things)

Thanks & best regards,


The problem is that doc,location, when inside the designer, is "about:blank", so the variable s, in this case, is undefined, causing the error.

Next week I will provide more guidance on this topic, as I think it's very important to allow integrate these type of templates into apps.