Implement "Back" one html page button

If your visitors' browsers support the navigation bar (Opera natively, Firefox with an extension, MSIE users luck out) you can add link elements to the page header, stating where the browser needs to go (up, down, next, previous, first, last, etc.).

That way, the visitor can use the same navigation bar (application buttons) for both the next and the previous set.

Obviously you'll still need to create a duplicate for moronic browsers like Microsoft's excuse.

Sorry I took so long to respond.

As OmegaJunior suggested, I downloaded a Firefox navigation bar and for some reason it did not work on my application.  I don't believe it is a problem with the navigation bar, but rather an issue with my applicaton.

I next tried to program it using a combination of php and javascript history.back() and history.forward(). The history.back() works fine.  However, I ran into a problem on the "Next" button. Suppose you go forward 10 pages and then back 5 pages.  Initially going forward 10 page requires SQL to get the next 20 vendors to display on each of the 10 pages. Secondly, when I go back 5 pages, I can simply use javascript document.back().  Thirdly, if I want to go forward 5 pages, when I click the Next button, I go back to my database to get the next set of vendors for pages 6 - 10.  I only want to hit my database when it is necessary.  My programming keeps track of what page I am on, how many pages I have gone forward and the maxinum number of pages I can go forward.   For example, if I am on page 5, I know I can use document.forward() for pages 6-10.  For pages 11,12, etc..., I know I have to hit my database.

My Next button is a submit button.  Is there a way I can programatically change the behavior of it to use the document.forward() or to hit my database?  I believe the answer is yes.  When I reenter my program, I know if the page has been created. If it has beencreated, I can issue document.forward() and drop out of my program. Otherwise, this requires going to the database.  I can do that since that is already in my program.

Is this a workable solution?  Have a better idea? I don't have my ego in this.


Thanks much!

sounds like you miss that you only can use document.forward(), history.next() if there was a hixtory.back() (or use of th eback button) right before ...

Hi,

First I've upped the point to 500.

I have made one enhancement to the browse function.  I require the operator to enter sufficient search criteria so that no more than 300 rows are returned  or max. 15 pages.  I think that,  from a practical functional and database resources perspective, is quite generous for the operator.

This little project has turned into somewhat of a nightmare.  The ideal solution to me is to implement Back and Next buttons using javascript, except when I have to hit the DB, and do not take an unnecessary php  trip to the server and back.  For example my Back and Next Buttons would be defined as follows:

<input type="btn1" value="Back"  onClick="history.back()" />      (not submit button)
<input type="btn2" value="Next"  onClick="history.forward()"/>  (not submit button)

My Next button when I have to hit the DB is:
<input  type="submit" value="Next">

Using browser history is a double edged sword.  On one hand it is easy to implement history.back() and history.forward().  On the other hand, it creats a few problems:

1. It makes it very difficult to keep my php navigation variables in sync with which keep track where I am at in the browse: $onPage, $maxPages (viewed), and $totalPages.  Javascript and php variables don't cross language boundaries very easily.

2. If I start a new browse and  Next to page 5, then hit the Back button 3 times ( on page 2), the Next button on page 2 is defined as hit the DB (e.g. that how it was defined when I origionally displayed page 2).  So when I click it I hit the DB to get to page 3.  I want to execute history.forward().

This approach is clearly wrong.


My latest effort was to define all my buttons as submit buttons:

Back javascript:
<input type="submit" value="Back" class="font-filler-button" onClick="this.form.$whichButton.value=this.name;" name="PJ" />  

Next javascript:      
<input type="submit" value="Next" class="font-filler-button" onClick="this.form.$whichButton.value=this.name;" name="NJ" />

Next hit DB:
<input type="submit" value="Next" class="font-filler-button" onClick="this.form.$whichButton.value=this.name;" name="ND" />

Note, I gave each button a name. PJ is Back using javascript, NJ is Next using javascript and ND is Next hitting the DB.

When I click the button, my program gets the navagation variables ($onPage, $maxPage & $totalPages) and determines which button was clicked.

If it is DB, I hit the database and increment and save the the $onPage and $maxPages vars  to a file and display my page.

If it is PJ or NJ here is my code:

I store my location data is a local file. It looks like this: 4|4|244  The variables are $onPage, $maxPages and $totalPages respectively.  In this case I've gone out 5 pages and stopped.

$contents = readPageNav();     //get the data from a local file
$line = explode("|", $contents);
$onPage = $line[0];
$maxPages = $line[1];
$totalPages = $line[2];


$whichButton=$_POST['$whichButton'];
switch ($whichButton) {
  case "PJ":
    if ($onPage > 1) {
      $onPage--;
      writePageNav($onPage, $maxPages, $totalPages, $lastVendor); //function to update nav file variables
      echo  '<script language="javascript"> history.back() </script> ' ;   //DOES NOT WORK
    exit();
    }
  case "NJ":
    if ($onPage < $maxPages) {
      $onPage++;
      writePageNav($onPage, $maxPages, $totalPages, $lastVendor);
      echo  '<script language="javascript"> history.forward() </script>' ;  //DOES NOT WORK
    exit();
    }
  default:
    break;
}

....
remainig code handles DB access, presentation and displaying buttons.

The echo statement, which execute javascript do not work. If I go out 5 pages, the nav variables are: 5|5|244 which is correct. When I hit the Back button twice, the nav variables are: 3|5|244, BUT I stay on page 5. This mean history.back() did not execute.  

--->>>  Any ideas on how I can get get the javascript to execute as shown above?  <<<---


I've thought about making links like you see on blogs:
<Previous> <1> <2> <3>... <14> <Last>

But this pesents its own set of problems.  My DB browse has to read the entire results of the search criteria, save every 20 row and store the name in an array so I can keep track of the first vendor on each page.  My SQL would have to be something like this:

$nextVendor = vendorArray[$onPage + 1];  //returns first vendor name on page 6

SELECT * FROM vendor  WHERE name >= '$nextVendor ' ORDER by name LIMIT 20;


--->>> Can someone suggest a better approach?  <<<---

Thanks much!

Cheers!

Another question, it it possible to add code to the end of my url so each page is uniquely identified.  Now the url on each page (1...15) looks like this:

http://localhost/ap/vndrSearch2.php

Can I add a page number at the end of the url like this and transfer to the 3rd page since it is unique?  For example:

header("location:vndrSearch2.php?page=3");

I know this is a method to pass a small amount of data between programs, but can it be treated las a unique url too?

Thanks again.

Cheers.