Digital Workshop

Fred

Interesting.

I'll admit that I know nothing about this issue, so perhaps my suggestion is way out from left field, or maybe even off the planet, but here it is.

1. I wonder if the count of 20 pages is attached to the Next Button, or if it is stored in a global variable.

2. What would happen if, when the number of successive clicks on the Next Button reached 19, you replaced that Next Button with another Next Button?

3. Does the count continue or reset?

This might be worth testing, because sometimes these way out ideas just happen to work.

Hi Ray,

Fortunately the next button (forward) has no limit. It just goes to whatever page is next.




Hi Fred,

Thanks for sharing this, as this information is not in the Help File.

Though thinking about it, it does make sense how "previous" could accumulate, so I can see how a limit buffer is set in place. I've basically used "previous" just to go back to a previous page, that does not have a previous button. Obviously I have been lucky -- so once again thanks for pointing this out.

I assume in a published publication, the end-user would keep clicking on "Previous" and in the end, after 20 times, the button would simply do nothing. So my way of thinking, is they would interpret they have reached their "previous visits" (like "back" on a web browser), so obviously another "home" or "goto" button would be required. (which in 99% of cases we would have -- especially after 20 previous pages). The "previous" buffer is re-initialised so another 20 records can be kept.

So I doubt you or Linda's pub will lock up. The "previous" will simply stop working until another click of a button initiates it again.

I have attached an IMP however, (using Linda's pub once again) showing one easy way of limiting the "previous" button to an example of 5 times -- then it will return to the Home page. (or main menu) Obviously you would know how to do this, but it may help others learning Opus.

Linda - would this approach be suitable for you?

Hi Steve



Point taken I just didn't explain what I meant as clearly as I could have done. So here goes again.

I was working on the theory that the normal way of moving through a pub is via the Next or Back Buttons. One has to move forward or back (or go somewhere else perhaps via a hyperlink) before one can go to previous.

This means there has to be a record of this movement kept somewhere -- otherwise, how can the Previous Button track the movement?

To my way of thinking, the logical places to store this movment history would be (i) in a global variable with a limit of 20 entries, or (ii) directly associated with the Previous Button.

If, as seems more logical, this history is stored in a limited global variable, I see no way of circumventing it.

On the other hand, if the history is directly associated with the Previous Button, there might just be a possibility of exceeding the 20 limit by having a series of Previous Buttons, P1, P3... etc.

As soon as P1 records 20 left-mouse clicks, what happens if P1 is disabled and replaced with P2?

Just another way out thought from the West

I'm afraid someone, especially a new OPUS user, will get confused by reading our postings, so I'm going to try to explain when you use BACKWARD, and when you use PREVIOUS. They are completely different. Most of the time you will ONLY use BACKWARD. PREVIOUS is for very special occassions.

BACKWARD
If you have a linear presentation with 100 Pages, each with a Button Object to go to the next Page, and one to go to the prior Page, you use Actions Go Forward, and Go Backward. No exceptions, these are the only two you should use.

PREVIOUS
In the above 100 Page example, let's create Page 101, but this is only a Help Page. It's not seen in the regular run of Pages. From any Page we want to be able to get Help, then we want to go back to the Page we just came from. You would create, for each Page, a Button Object and using a Left Mouse Click you'd have an Action of Go To Page 101 (Help). On our new Help Page, we will create one Button Object with a Left Mouse Click Trigger, and an Action of PREVIOUS.

You can NOT PREVIEW this effectly from Page 101, because there is no previous Page. Go to any other Page (1-100), click the Help Button, then click the return Button on the Help Page, and it will take you to the original Page. (Programmers: This is like a RETURN after using a GOTO SUB).

Now let's imagine we've created multiple Help Pages, and from each of them, we want to be able to go to an even higher second level of Help. We could create Buttons on each Help with a Go to Page Super Help. From Super Help we would put a Button with another Previous Action.

Preview from a Page between 1 and 100. Select the first level Help, then select the second level of Help. By using Previous, OPUS will take us back to Help level 1, then back to the initial Page where we started our Preview.

This is an example of just two levels of Previous. OPUS can have 20. If you used 25 levels, and you tried to go back, it would stop after 20, and give you an error message to the effect that there is no other Previous Pages.

Once you get the concept of Previous, it's easier to understand than to explain.

Fred

This is a good and timely explanation which many people will find useful.

When I first read this thread I wondered why I had never come across the problem you raised. It never even occurred to me that it could exist.

I have one pub with 1100+ pages. It has a main menu which links to 26 submenus. Each submenu has multiple links to specific pages within their alphabetic range. Every alpha page has from 1 to 20+ hyperlinks which let the user jump to other pages, from which they can make yet more jumps...

The most common movements made in this pub are leaps from one page to another, with a real need to be able to leap back from the target page to the launch page. For this reason, every page has a Previous Button.

Even with a large pub that encourages leaping from page to page, I have no reports of anyone encountering the 20-level limit, so on the strength of that, I'm going to stop worrying and forget I ever read this thread

I believe it unlikely that any user would want to browse through this pub -- it is just not built for that style of use. However, 30+ years of working with computers and customers has taught me that as soon as I make a decision that something isn't needed, you can bet that someone will prove that they can't live without it So, I have Next and Back buttons on each page.

Because of the confusion between Previous and Back I include a comprehensive navigation button tutorial that explains this difference. So far so good with no problems reported.

To add yet more to this intriguing thread...

Hello DW,

Here is an idea and suggestion for the use of "Previous" in the new version of Opus.

Can it be changed so that when the 20 limit is reached, it simply cycles? That should stop any problems with a Previous action inadvertently leaving an end-user in limbo in a publication. (or when it reaches its limit we have a Goto PageX option, like on the Goto Page on EXIT?)

Perhaps this could be introduced by expanding the OpusScript 'GotoPreviousPage()' function feature?