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CH 14 - CUSTOMISING POWERBASE ============================= This chapter describes all the things you can do to influence the way Powerbase looks and functions. 14.1 Overall control of the database ===================================== A Powerbase database is normally controlled in four ways:− • mouse-clicks on the keypad • keystrokes which mimic the actions of the keypad • choices from the main menu • choices from the icon-bar menu Each of these can be disabled by deselecting one of the option switches on the Password window (see 11.2). The main reason why you might want to do this is to provide limited facilities to someone else who is using your database. It doesn’t, on the face of it, make a lot of sense to disable both the keypad and the keystroke-equivalents as no browsing or editing would then be possible. You can, however, place some or all of the keypad buttons on the record screen itself (see 4.2.9) thus allowing you to choose what functions you want to allow access to. You might, for example, wish to provide only the “Next record”, “Previous record” and “Search” buttons. Define these as Button fields at the time the record is being designed then disable the keypad and keystroke equivalents. Other switches in the Password window enable you to stop the user exporting data as CSV files or subsets or printing reports. 14.2 Defining the function keys ================================ Any button on the keypad may have its action duplicated by one of the keys F1-F11, with or without the use of Shift or Ctrl. Point at the button to which you wish to assign a key and click MENU to display the keypad menu. Assign leads to a window which shows the present key-assignment, if any. Use the “bump” icons to select the required function key and, if desired, select one of the switches for Shift and Ctrl. Click on the Assign button and you will now find that the assigned key exactly mimics the keypad button − even to the extent of actually “pressing” the button when you type the key. One important constraint should be noted. Whatever key you assign to the Search button, Powerbase will automatically assign the shifted version of this key to the “search all subfiles” function (see 2.3.1). For this reason you should assign an unshifted key to Search and avoid assigning the shifted version to any other keypad button. Similarly, assigning a key to the New record button automatically assigns the shifted key to the Copy record function. You may save your key definitions by choosing Save choices from the keypad menu and you will find them operative next time you use Powerbase. Please note that your definitions work with all the databases you use; there is no facility for saving separate assignments for each database. The default keystrokes (together with some which duplicate non-keypad actions) are listed in Appendix B. If they have been redefined you may restore the defaults by choosing Defaults from the keypad menu. If you wish to “lose” the redefined keystrokes permanently you should restore the defaults as described then Save choices. List keys on the keypad menu displays all the key definitions (including those for non-keypad functions) in a window from which the information may be saved as a text file. Function keys may also be used to enter data into record fields or writable icons in dialogue boxes. The actual programming of the keys is done at the command line which is accessed by pressing f12. This takes you temporarily out of the desktop and gives you a “star” prompt at the bootm of the screen. Suppose you want to program f3 to enter the word “Powerbase”. Type, at the star prompt: Key3 Powerbase and press Return twice to return to the desktop. The string assigned to the key may be entered by typing Ctrl-Shift-f3. Any of the keys f1-f9 may be programmed and the string is always entered by typing the key with Ctrl and Shift both held down. 14.3 Print options =================== The Print options window, accessible from the Print submenu or by typing Shift Print, was described in some detail in 3.5 but a few features still require comment. You may set up this window to suit the requirements for a particular database and then save the set-up as part of the database by clicking on Save choices with the in database radio button selected. A Save box appears which, by default, saves the options file in the PrintRes directory under the name PrtOptions. A file of that name, in that directory, is read when the database is subsequently re-opened and will set up the print options as you left them. You can, of course, give the file a different name and even save it in a different place if you wish. Print option files are recognisable by their icon, which bears a large “P”. Some users like to have several of them in their database’s PrintRes directory to do different jobs. It is always possible to load the one you want by opening the PrintRes directory (Show resources from Print submenu or, alternatively, Ctrl R) and double-clicking on the required file or dragging it onto the record window. Should you wish to “throw out” your special keys set-up during a working session with the database you can restore the default settings by clicking Load default. If you like your own setup better than the default and wish to use it for all your databases then select the as default radio button before clicking Save choices. The file PrtOptions will then be saved inside Powerbase itself. Note also that, provided the Print options window has not been closed, the Cancel button will restore it to the state it was in when you opened it. 14.4 CSV options ================= It was explained in 8.2 how to access the CSV options window and what the pop-up menus and option switches are for. The buttons Save choices, as default, in database, Load default and Cancel work in a similar way to that described above for the Print options window − with one notable difference. No Save box appears when you Save choices in database; the file is saved as a plain text file called CSVoptions. This more limited behaviour has been chosen because, although you might want several Print options files for different jobs, it is unlikely that you will have a use for several CSV options files. 14.5 Preferences ================= Several previous references have been made to the Preferences window which is opened from the icon-bar menu. A full description of the choices offered in this window follows. 14.5.1 Separators in date and time fields ----------------------------------------- By default dates have the format dd-mm-yy or dd-mm-yyyy, i.e. the separator is a hyphen. You might wish to use a colon, full-stop, slash or other character. You may type any non-numeric character when entering dates and Powerbase will re-format the field to use the specified character. Only fields actually defined to be of type Date behave in this way. Fields defined to be of type Time have the form hh:mm:ss, i.e a colon is used as the separator. As in the case of dates, you may type any non-numeral you like during data entry and Powerbase will reformat the time as above. To change either of these separators type the required character into the writable icon in place of the default. 14.5.2 Wild-cards ----------------- The use of wild-card characters is described in 2.7.5 and 3.3.4. By default “#” represents a single character and “$” a group of characters which need not be matched. You may change either or both wild-card characters if you wish in the same way as described above for date and time separators. 14.5.3 Option switches ---------------------- Record edits as CSV file when ON causes a CSV file called NewData to be created in PrintJobs. New and edited records are saved in this file which may then be used to enter data into another Powerbase database. Launch new copy ··············· When ON, causes another copy of Powerbase to be loaded when you double-click on a database, instead of closing the current database. This can be useful if you want to access several databases at once, as one copy Powerbase only supports the use of a single database. If there is a dormant copy of Powerbase on the icon-bar (i.e. one with “No data” under its icon) then double-clicking a database sends it to that copy rather than launching a new one. With the switch OFF double-clicking on a database closes down an already-open database before opening the new one. Even then you can load multiple copies of Powerbase by double-clicking on Powerbase itself and then open a different database in each by dragging the databases to the icons. Recalculate on opening ······················ Affects Composite fields (see 6.2) whose associated formulae make use of the system variable TIME$. With the switch OFF the contents of such fields are recalculated only when a record is displayed. This might not be good enough where, for example, TIME$ is used in a User function (see 6.3) to keep track of people’s current ages. Selecting the switch causes Powerbase to scan the whole file and update such fields when the database is first opened. Blank record on deletion ························ If this switch is OFF then deleting a record from the database merely removes all references to its key(s) from the index(es), leaving the actual record data untouched in the Database file. Although such “deleted” records will be overwritten when new records are entered, the situation may be deemed unsatisfactory from a security point of view since the “deleted” records can be examined by simply loading Database into Edit. If the switch is ON deletion causes the relevant record to be over-written with a blank record. Keep descriptor with data ························· Alters the behaviour of fields as they are dragged around the screen when designing the record layout. With the switch OFF you may drag the data field and the descriptor independently of one another. With the switch ON this is true only of the descriptor; if you drag the data field the descriptor jumps to its “normal” position to the left of the data field as soon as you release the mouse button. Validate input ·············· Turns data validation (see Ch 5) ON and OFF. If you ever find yourself unable to escape from a field linked to a validation table you can bring up the Preferences window, deselect this switch and try again. Display linked table data ························· Every time the caret enters a field with a link to a validation table a window showing data from the relevant validation table row appears to the right of the field if the switch is ON. This is either useful or infuriating, depending on your point of view. If turned OFF you can still call up the window for a specific field by double-clicking on the field with SELECT (see 5.5). Warn of external deletion ························· Since deleting data from an External field (see 2.6) involves the deletion of an actual file you will probably appreciate being warned when you are about to do it. With this switch ON you will be given a warning and the opportunity to change your mind. Warn of duplicates ·················· The creation of records with identical primary keys can be prohibited if so desired (see 11.2.1). Normally, however, they are permitted. You may, if you wish, turn this switch ON to issue a warning that such a record is about to be created. Default action on Return ························ According to the Acorn Style Guide for RISC OS typing Return anywhere inside a dialogue box ought to have the same effect as clicking on the default action button (that’s the one with the yellow channel border) regardless of which writable icon the caret is in. If that’s what you want then turn this switch ON. Many users (including the author!) hate it and prefer the default action to take place only if the caret is in the last writable icon when Return is typed. Hence the default setting, which is OFF. Strip leading spaces ···················· Is ON by default. Spaces at the beginning of data fields will be stripped before the record is written to the file. Turn the switch OFF if you actually want spaces in this position Strip trailing spaces ····················· Should normally be left ON to avoid unwanted spaces at the right of data fields. It is easy to press the space-bar by accident when entering data quickly and you might not notice that a field has one or more spaces between the end of the last word and the caret. Balance every <n> records ························· The need to balance indices and the use of this option is explained in 10.6. Remember place in subfile ························· With this switch OFF a change of subfile leads to the display of the first record in the new subfile. If you are doing a lot of hopping back and forth between subfiles to inspect specific records you might want to select the switch. It is then just as if you had bookmarks in separate chapters of a book; when you return to a subfile you have previously visited you will see the same record you were viewing when you left that subfile. 14.5.4 Save indices (Default: Manual) ------------------------------------- Indices are always saved whenever you close a database or quit Powerbase and only fear of power cuts or system failure (which includes some kind person switching off your computer!) need make you concerned about saving them yourself. With the Manual setting nothing happens during normal working unless you click Force update on the keypad. Selecting Automatic or Warn only allows you to type in a suitable time interval (default = 10 min) at which Powerbase will either issue a warning to save your indices (using Force update) or actually save them for you. 14.5.5 Start editing at ----------------------- When a record is displayed the caret is placed, by default, in the first editable field. Editing may be made to start at a different field by choosing Start editing from the Field submenu (see 2.5.4) or, alternatively, by placing the caret in the required field and typing Ctrl-S. The tag of the relevant field is stored in this writable icon in the Preferences window and can be saved along with the other preferences. 14.5.6 Application for ImpulseII data-merging --------------------------------------------- As noted elsewhere (9.2) Powerbase can merge directly into a suitably-formatted Impression document by simply dropping the document icon onto the record window. The dialogue box which then appears contains a writable icon which shows the application with which Powerbase will merge. This name is, by default, “Impression”, but may be altered by users for their own purposes. An application which will receive data from Powerbase in this way must make use of the ImpulseII protocols as defined by Computer Concepts. Even if you are using Style or Publisher the name to which these applications respond is still “Impression”. 14.5.7 Save choices ------------------- This section of the window works exactly as it does for CSV options (see 14.4) as do the Load default and Cancel buttons. 14.6 Colours of key fields and linked fields ============================================= These may be selected in a window reached by choosing Colours from the Miscellaneous submenu. The following default colours are used:− Type Foreground Background Descriptor of key field (inactive) dark blue light grey Descriptor of key field (active) red light grey Data icon of primary key field(s) black pale yellow Data icon of field linked to validation table dark green white Clicking with SELECT on the descriptor and data icons within this window makes either the foreground or background (depending on the setting of the two radio buttons) cycle through the available colours. Clicking with ADJUST cycles through the colours in the opposite direction. Apply allows you to see the effect of the changes and Defaults enables you to return the colours to what they were before, provided you haven’t clicked on Save choices. The latter applies the new colours and saves the changes so that they are effective next time the database is used. Different databases may have different colours. 14.7 The Config file ===================== Inside the Powerbase application directory is a sub-directory called Resources. The file Config, which will be found there, determines certain aspects of the program’s operation which will seldom need changing. Changes made to Config take effect only when Powerbase is next loaded. If you load the file into Edit you will see lines which determine:− • maximum number of fields per record (default = 100, maximum = 127) • maximum number of subsidiary indices (default = 10) • maximum number of validation tables (default = 10) • maximum number of pop-up menu fields (default = 3) • maximum number of columns in a validation table (default = 20) • whether submenus off the icon-bar menu open on the left instead of on the right as normal. This avoids the overlapping submenus which can occur but many users hate it! Put YES, instead of NO, at the start of the line if you want the icon-bar menu to work like that. • background colour of record window. Default (1) is pale grey. • whether password entry is forced to uppercase. Earlier versions of Powerbase allowed only uppercase letters in passwords and some users may wish to place YES at the start of this line. Current versions of Powerbase allow both upper and lowercase letters. • display option for directories opened by buttons on the record window. Default is -si (small icons). This may be changed to -li or -fi (large icons and full information respectively). The options to sort by name, type, date and size (-sn, -st, -sd, -ss) may also be added after a space. • method used for storing Text, Sprite and Draw files which are linked to External fields. A description of the old and new methods is given below. When altering Config be sure to leave a space between the number or word which begins the line and the explanation. 14.7.1 Pathnames for External file objects ------------------------------------------ The system used is detemined by pacing the word OLD or NEW at the beginning of the relevant line in Config. The OLD method of deriving the pathname for the stored file object is as follows:− (a) Divide the record number by 4900. The integer part of the result is used as the name of the top-level directory. (b) Divide the record number by 70. The integer part of the result is used as the name of the second-level directory. (c) The integer remainder of dividing the record number by 70 is used as the actual filename. This is an awkward system if you are in the habit of using the filer windows to sift through the files rather than relying on Powerbase to display them. To calculate the number of the record to which the file belongs you have to take the number forming the name of the file’s parent directory, multiply by 70 and add the number corresponding to the filename itself. The new system improves on this. Steps (a) and (b) are identical. The filename itself, however, uses the whole record number preceded by Rec, e.g. a file associated with record 275 will be called Rec275. You can therefore use the RISC OS filer’s Find command to locate and examine the file. Under the OLD system such a file would be called 65. The default setting in Config is NEW. Users should be aware that the earliest version of Powerbase to support this feature is v. 6.94, dated 02-03-96. This and later versions understand both methods of storage and will rename files according to the Config setting. Thus, a database created under an earlier version in which record 275 is represented by a file called 65 will have that file renamed to Rec275 simply by displaying the record, even if the file itself is not loaded. Once this has happened the file cannot be found by an earlier version of Powerbase. Under most circumstances this should not cause any difficulty; just make sure you are using v. 6.94 or later. Should you wish to run a database under an earlier version and access the External file objects from the record window you must first convert the filenames to the OLD format. To do so place OLD in the Config file as described above, then load Powerbase. Open your database and click on the Play button. Click on Stop when all records have been displayed. If you use more than one subfile you will need to do this for each occupied subfile. OLD may be converted to NEW pathnames in a similar way. 14.8 The Messages file ======================= This text file in the Resources sub-directory contains all the error and warning messages used by Powerbase including those for Acorn’s interactive Help application. The wording may be altered if you wish. Many error messages contain the string “%0” and possibly “%1” and “%2”. Data items are substituted for these when the message is printed so don’t omit them or alter their logical placement within the message.