ES: Opening the 5th book component from the end

[rombanks]

Hello fellows,

I wonder what is the best way to find the 5th book component from the end of the book (so the 1st book component to count is basically the last one). 

I can loop through all components and get a list of all of them. Then, I guess, I need to somehow put them into an array and find the 5th one from the bottom?

Any ideas will be appreciated!

[Mike-Hardy]

I cannot see any alternative to iterating through all the book components, storing the component ids as you go..

I'd use a buffer big enough to hold only 5 component ids. Store each successive component id you find in location (counter modulo 5) - so it's effectively a circular buffer. When you reach the last component in the book, the component you want will be the next entry in the circular buffer. This method saves memory, and handles a book of any size.

Whether or not you use the above method, ensure you gracefully handle a book with fewer than 5 components. In the above case, I'd intiialize the buffer to nulls, and check for a non-null value at the end.

[Russ Ward]

Mike, Rom, all this sounds good so far, but why bother with buffers at all? I would just go to the end with FP_NextComponentInBook, then step backwards 5 times with FP_PrevComponentInBook. Given the speed of this type of operation, I don't think that you would see any performance issues even with a very large book.

Russ

[rombanks]

Hi Russ,

I wonder why there is no LastComponentInBook. It would be easier to start counting from it.

[rombanks]

Hi Mike,

Thank you for your response!

How would you create and manage this buffer?

[frameexpert]

This is how I would do it:

#target framemaker

var comps = [];
var book = app.ActiveBook;
var bookComp = book.FirstComponentInBook;
while (bookComp.ObjectValid ()) {
    // put the components into the array in reverse order.
    comps.unshift (bookComp);
    bookComp = bookComp.NextBookComponentInDFSOrder;
}

alert (comps[4].Name);

[rombanks]

Hi Rick,

Thank you for your response and for the suggested code! What does the unshift method do? I couldn't find it in the scripting guide.

Thank you!

[frameexpert · Accepted solution]

unshift is an array method that puts an item into the front of the array instead of the back. So if you had an array of numbers:

var array = [1, 2, 3, 4, 5];

and did this:

array.unshift (6);

you would have this:

[6, 1, 2, 3, 4, 5]

Normally, you use push to put items on an array:

array.push (6);

would give you:

[1, 2, 3, 4, 5, 6]

[rombanks]

Hi Rick,

Thank you for the explanations!

Now I see that unshift is a standard JS method. I need to learn more about arrays.

Thank you for your help!

[rombanks]

Hello fellows,

Let's say I have a book open and also a standalone FM file that is not part of that book.

I previously opened this standalone FM file as follows:

var openFM = Open(dname, openParams, openReturnParams), where dname is the full name of that FM file, openFileParams and openFileReturnParams are defined in a function that lists all relevant open params.

var openParams = getOpenPrefs();

var openReturnParams =  new PropVals();

function getOpenPrefs() {

    var params, i;

    params = GetOpenDefaultParams();

    i = GetPropIndex(params, Constants.FS_RefFileNotFound);

    params.propVal.ival = Constants.FV_AllowAllRefFilesUnFindable;  

    i = GetPropIndex(params, Constants.FS_FileIsOldVersion);

    params.propVal.ival = Constants.FV_DoOK;

    i = GetPropIndex(params, Constants.FS_FontChangedMetric);

    params.propVal.ival = Constants.FV_DoOK;

    i = GetPropIndex(params, Constants.FS_FontNotFoundInCatalog);

    params.propVal.ival = Constants.FV_DoOK;

    i = GetPropIndex(params, Constants.FS_FontNotFoundInDoc);

    params.propVal.ival = Constants.FV_DoOK;

    i = GetPropIndex(params, Constants.FS_LockCantBeReset);

    params.propVal.ival = Constants.FV_DoOK;  

    i = GetPropIndex(params, Constants.FS_FileIsInUse);

    params.propVal.ival = Constants.FV_OpenViewOnly;

    return (params);

}

After getting the 5th book component, I open it as follows:

var T_FM = comps[4].Name;

var openT_FMParams = getOpenPrefs();

var openT_FMReturnParams =  new PropVals();

var openT_FM = Open(T_FM, openT_FMParams , openT_FMReturnParams ).

So now, I have 2 FM files open in addition to the book. The active FM file is the 5th book component that I just opened.

Now, I'd like to import formats from the 5th book component to the standalone FM file (dname) and then close the 5th book component.

I tried doing that as follows:

openFM.SimpleImportFormats(openT_FM, Constants.FF_UFF_COND|Constants.FF_UFF_FONT|Constants.FF_UFF_PAGE |Constants.FF_UFF_PGF|Constants.FF_UFF_REFPAGE|Constants.FF_UFF_TABLE|Constants.FF_UFF_VAR|Constants.FF_UFF_XREF);

openT_FM.Close(Constants.FF_CLOSE_MODIFIED, true);

This part does not work for a reason that is unclear to me. What could be the cause of this problem?

Thank you for your input in advance!

[frameexpert]

After the Open method, you should confirm that the template did open correctly.

if (openT_FM.ObjectValid () === 1) {
    // opened correctly.
}

Also, there is a special constant for importing all formats:

openFM.SimpleImportFormats(openT_FM, Constants.FF_ALL);

As far as closing the template without saving changes, all you need is this:

openT_FM.Close(true);

[rombanks]

Hi Rick,

Thank you for your response. It works only if all the operations described above are defined within the same function. But what if I'd like to split that into 2 functions?

How, for example, do I pass the openFM variable defined and opened in Function A to Function B that will open openT_FM and import the formats to openFM? How do I make local function var's visible to other functions?

Thank you for your explanations in advance!

[rombanks]

Hi Rick,

Let's say I would like not to count excluded book components that appear at the end of the book. So I tried changing the while statement as follows:

1. ...
2. while (bookComp.ObjectValid () & bookComp.ExcludeBookComponent !==1) { 
3.     // put the components into the array in reverse order. 
4.     comps.unshift (bookComp); 
5.     bookComp = bookComp.NextBookComponentInDFSOrder; 
6. } 
7.  
8. alert (comps[4].Name);

However, in this case, the  comps[4] element is one of the first components of the book. Any idea why comps[4] is now counted from the top?

Thank you!

[frameexpert]

Try using && on line 2.

[rombanks]

Hi Rick,

I appreciate your response.

I tried that previously. As a result, comps[4] is an LOT file (which is the fourth component from the top of the book ).