Tag: APEX

BIG checkboxes

Getting older, it’s getting harder to see and click those tiny checkboxes…

checkboxestoosmall

csscheckboxes

input[type=checkbox] {
/* Double-sized Checkboxes */
-ms-transform: scale(2); /* IE */
-moz-transform: scale(2); /* FF */
-webkit-transform: scale(2); /* Safari and Chrome */
-o-transform: scale(2); /* Opera */
}

checkboxesbig

CAN YOU SEE THEM NOW? Ah, good. That’s all right then.

Brought to you by dept-of-coding-by-copy-and-paste.

Google Map Apex Plugins

I’ve published two three Apex Region Plugins on apex.world that allow you to incorporate a simple Google Map region into your application. They’re easy to use, and you don’t need to apply for a Google API key or anything like that (although you can plug your key in if you have one, which enables a few additional features).

1. Simple Map

plugin-simplemap-preview

This allows you to add a small map to a page to allow the user to select any arbitrary point. If you synchronize it with an item on your page, it will put the Latitude, Longitude into that item. If the item has a value on page load, or is changed, the pin on the map is automatically updated.

Source

2. Report Map

plugin-reportmap-preview.png

This allows you to add a map to a page, and based on a SQL query you supply, it will render a number of pins on the map. Each pin has an ID, a name (used when the user hovers over a pin), and an info text (which can be almost any HTML, rendered in a popup window when the user clicks a pin).

If the user clicks a pin, the ID can be set in a page item.

Source

3. GeoHeatMap

Visualise a large set of data points on the map using the Google Maps “Heatmap” visualisation. All you need to do is supply a SQL Query that returns the data points to show, and the visualisation library does the rest.

plugin-heatmap-preview

Your SQL Query must be in the following format:

select lat, lng, weight from mydata;

You can set the Map Style (e.g. to the light blue/greyscale style you see above) easily on this plugin; just copy-and-paste the style codes from a site like snazzymaps.com.

Source

I’m very open to feedback, issues and contributions on all of these. Best way is to raise an issue on the associated github page. Have fun!

Refer to my Plugins page for future updates.

Apex API for Tabular Forms

grid-edit
Ever since I started exploring the idea of using a TAPI approach with Apex, something I was never quite satisfied with was Tabular Forms.

They can be a bit finicky to work with, and if you’re not careful you can break them to the point where it’s easier to recreate them from scratch rather than try to fix them (although if you understand the underlying mechanics you can fix them [there was an article about this I read recently but I can’t find it now]).

I wanted to use the stock-standard Apex tabular form, rather than something like Martin D’Souza’s approach – although I have used that a number of times with good results.

In the last week or so while making numerous improvements to my TAPI generator, and creating the new Apex API generator, I tackled again the issue of tabular forms. I had a form that was still using the built-in Apex ApplyMRU and ApplyMRD processes (which, of course, bypass my TAPI). I found that if I deleted both of these processes, and replaced them with a single process that loops over the APEX_APPLICATION.g_f0x arrays, I lose a number of Tabular Form features such as detecting which records were changed.

Instead, what ended up working (while retaining all the benefits of a standard Apex tabular form) was to create a row-level process instead. Here’s some example code that I put in this Apex process that interfaces with my Apex API:

VENUES$APEX.apply_mr (rv =>
  VENUES$TAPI.rv
    (venue_id   => :VENUE_ID
    ,name       => :NAME
    ,version_id => :VERSION_ID
    ));

The process has Execution Scope set to For Created and Modified Rows. It first calls my TAPI.rv function to convert the individual columns from the row into an rvtype record, which it then passes to the Apex API apply_mr procedure. The downside to this approach is that each record is processed separately – no bulk updates; however, tabular forms are rarely used to insert or update significant volumes of data anyway so I doubt this would be of practical concern. The advantage of using the rv function is that it means I don’t need to repeat all the column parameters for all my API procedures, making maintenance easier.

The other change that I had to make was ensure that any Hidden columns referred to in my Apply process must be set to Hidden Column (saves state) – in this case, the VERSION_ID column.

Here’s the generated Apex API apply_mr procedure:

PROCEDURE apply_mr (rv IN VENUES$TAPI.rvtype) IS
  r VENUES$TAPI.rowtype;
BEGIN
  log_start('apply_mr');

  UTIL.check_authorization('Operator');

  IF APEX_APPLICATION.g_request = 'MULTI_ROW_DELETE' THEN
  
    IF v('APEX$ROW_SELECTOR') = 'X' THEN
      VENUES$TAPI.del (rv => rv);      
    END IF;

  ELSE

    CASE v('APEX$ROW_STATUS')
    WHEN 'C' THEN

      r := VENUES$TAPI.ins (rv => rv);

    WHEN 'U' THEN

      r := VENUES$TAPI.upd (rv => rv);

    ELSE
      NULL;
    END CASE;

  END IF;

  log_end;
EXCEPTION
  WHEN UTIL.application_error THEN
    log_end('application_error');
    RAISE;
  WHEN OTHERS THEN
    UTIL.log_sqlerrm;
    RAISE;
END apply_mr;

The code uses APEX$ROW_STATUS to determine whether to insert or update each record. If the Delete button was pressed, it checks APEX$ROW_SELECTOR to check that the record had been selected for delete – although it could skip that check since Apex seems to call the procedure for only the selected records anyway. The debug logs show Apex skipping the records that weren’t selected.

Now, before we run off gleefully inserting and updating records we should really think about validating them and reporting any errors to the user in a nice way. The TAPI ins and upd functions do run the validation routine, but they don’t set up UTIL with the mappings so that the Apex errors are registered as we need them to. So, we add a per-record validation in the Apex page that runs this:

VENUES$APEX.val_row (rv =>
  VENUES$TAPI.rv
    (venue_id   => :VENUE_ID
    ,name       => :NAME
    ,version_id => :VERSION_ID
    )
  ,region_static_id => 'venues');
RETURN null;

As for the single-record page, this validation step is of type PL/SQL Function (returning Error Text). Its Execution Scope is the same as for the apply_mr process – For Created and Modified Rows.

Note that we need to set a static ID on the tabular form region (the generator assumes it is the table name in lowercase – e.g. venues – but this can be changed if desired).

The val_row procedure is as follows:

PROCEDURE val_row
  (rv               IN VENUES$TAPI.rvtype
  ,region_static_id IN VARCHAR2
  ) IS
  dummy            VARCHAR2(32767);
  column_alias_map UTIL.str_map;
BEGIN
  log_start('val_row');

  UTIL.pre_val_row
    (label_map        => VENUES$TAPI.label_map
    ,region_static_id => region_static_id
    ,column_alias_map => column_alias_map);

  dummy := VENUES$TAPI.val (rv => rv);

  UTIL.post_val;

  log_end;
EXCEPTION
  WHEN UTIL.application_error THEN
    log_end('application_error');
    RAISE;
  WHEN OTHERS THEN
    UTIL.log_sqlerrm;
    RAISE;
END val_row;

The pre_val_row procedure tells all the validation handlers how to register any error message with APEX_ERROR. In this case, column_alias_map is empty, which causes them to assume that each column name in the tabular form is named the same as the column name on the database. If this default mapping is not correct for a particular column, we can declare the mapping, e.g. column_alias_map('DB_COLUMN_NAME') := 'TABULAR_FORM_COLUMN_NAME';. This way, when the errors are registered with APEX_ERROR they will be shown correctly on the Apex page.

Things got a little complicated when I tried using this approach for a table that didn’t have any surrogate key, where my TAPI uses ROWID instead to uniquely identify a row for update. In this case, I had to change the generated query to include the ROWID, e.g.:

SELECT t.event_type
      ,t.name
      ,t.calendar_css
      ,t.start_date
      ,t.end_date
      ,t.last_updated_dt
      ,t.version_id
      ,t.ROWID AS p_rowid
FROM   event_types t

I found if I didn’t give a different alias for ROWID, the tabular form would not be rendered at runtime as it conflicted with Apex trying to get its own version of ROWID from the query. Note that the P_ROWID must also be set to Hidden Column (saves state). I found it strange that Apex would worry about it because when I removed the ApplyMRU and ApplyMRD processes, it stopped emitting the ROWID in the frowid_000n hidden items. Anyway, giving it the alias meant that it all worked fine in the end.

The Add Rows button works; also, the Save button correctly calls my TAPI only for inserted and updated records, and shows error messages correctly. I can use Apex’s builtin Tabular Form feature, integrated neatly with my TAPI instead of manipulating the table directly. Mission accomplished.

Source code/download: https://bitbucket.org/jk64/jk64-sample-apex-tapi

Apex API – call a package for all your DML

If you create an Apex form based on a table, Apex automatically creates processes of type Automatic Row Fetch and Automatic Row Processing (DML) as well as one item for each column in the table, each bound to the database column via its Source Type. This design is excellent as it’s fully declarative and is very quick and easy to build a data entry page for all your tables.

The downside to this approach is that if you want to use a Table API (TAPI) to encapsulate all DML activity on your tables, you need to write a whole lot of code to replace the processes that Apex created for you. In order to mitigate this as much as possible, I’ve augmented my code generator with an “Apex API” generator. This generates a second package for each table which can be called from Apex, which in turn calls the TAPI to run the actual DML. In addition, the validations that are performed by the TAPI are translated back into Apex Errors so that they are rendered in much the same way as built-in Apex validations.

Probably the best way to explain this is to show an example. Here’s my EMPS table (same as from my last article):

CREATE TABLE emps
  (emp_id       NUMBER NOT NULL
  ,name         VARCHAR2(100 CHAR) NOT NULL
  ,emp_type     VARCHAR2(20 CHAR) DEFAULT 'SALARIED' NOT NULL
  ,start_date   DATE NOT NULL
  ,end_date     DATE
  ,dummy_ts     TIMESTAMP(6)
  ,dummy_tsz    TIMESTAMP(6) WITH TIME ZONE
  ,life_history CLOB
  ,CONSTRAINT emps_pk PRIMARY KEY ( emp_id )
  ,CONSTRAINT emps_name_uk UNIQUE ( name )
  ,CONSTRAINT emp_type_ck
     CHECK ( emp_type IN ('SALARIED','CONTRACTOR')
  );
CREATE SEQUENCE emp_id_seq;

By the way, my table creation script calls DEPLOY.create_table to do this, which automatically adds my standard audit columns to the table – CREATED_BY, CREATED_DT, LAST_UPDATED_BY, LAST_UPDATED_DT, and VERSION_ID. My script also calls GENERATE.journal for the table which creates a journal table (EMPS$JN) and a trigger (EMPS$TRG) to log all DML activity against the table.

I then call GENERATE.tapi which creates the Table API (EMPS$TAPI) which has routines for validating, inserting, updating and deleting rows (or arrays of rows using bulk binds) of the EMPS table.

Finally, I call GENERATE.apexapi which creates the Apex API (EMPS$APEX) which looks like this:

Package Spec: EMPS$APEX

create or replace PACKAGE EMPS$APEX AS
/**************************************************
 Apex API for emps
 10-FEB-2016 - Generated by SAMPLE
**************************************************/

-- page load process
PROCEDURE load;

-- single-record page validation
PROCEDURE val;

-- page submit process
PROCEDURE process;

END EMPS$APEX;

Notice that these routines require no parameters; the API gets all the data it needs directly from Apex.

Package Body: EMPS$APEX

create or replace PACKAGE BODY EMPS$APEX AS
/*******************************************************************************
Table API for emps
10-FEB-2016 - Generated by SAMPLE
*******************************************************************************/

PROCEDURE apex_set (r IN EMPS$TAPI.rowtype) IS
  p VARCHAR2(10) := 'P' || UTIL.apex_page_id || '_';
BEGIN
  log_start('apex_set');

  sv(p||'EMP_ID',          r.emp_id);
  sv(p||'NAME',            r.name);
  sv(p||'EMP_TYPE',        r.emp_type);
  sd(p||'START_DATE',      r.start_date);
  sd(p||'END_DATE',        r.end_date);
  st(p||'BLA_TSZ',         r.bla_tsz);
  st(p||'DUMMY_TS',        r.dummy_ts);
  sv(p||'CREATED_BY',      r.created_by);
  sd(p||'CREATED_DT',      r.created_dt);
  sv(p||'LAST_UPDATED_BY', r.last_updated_by);
  sd(p||'LAST_UPDATED_DT', r.last_updated_dt);
  sv(p||'VERSION_ID',      r.version_id);

  log_end;
EXCEPTION
  WHEN UTIL.application_error THEN
    log_end('application_error');
    RAISE;
  WHEN OTHERS THEN
    UTIL.log_sqlerrm;
    RAISE;
END apex_set;

FUNCTION apex_get RETURN EMPS$TAPI.rvtype IS
  p  VARCHAR2(10) := 'P' || UTIL.apex_page_id || '_';
  rv EMPS$TAPI.rvtype;
BEGIN
  log_start('apex_get');
  
  rv.emp_id     := nv(p||'EMP_ID');
  rv.name       := v(p||'NAME');
  rv.emp_type   := v(p||'EMP_TYPE');
  rv.start_date := v(p||'START_DATE');
  rv.end_date   := v(p||'END_DATE');
  rv.bla_tsz    := v(p||'BLA_TSZ');
  rv.dummy_ts   := v(p||'DUMMY_TS');
  rv.version_id := nv(p||'VERSION_ID');
    
  log_end;
  RETURN rv;
EXCEPTION
  WHEN UTIL.application_error THEN
    log_end('application_error');
    RAISE;
  WHEN OTHERS THEN
    UTIL.log_sqlerrm;
    RAISE;
END apex_get;

FUNCTION apex_get_pk RETURN EMPS$TAPI.rvtype IS
  p  VARCHAR2(10) := 'P' || UTIL.apex_page_id || '_';
  
  rv EMPS$TAPI.rvtype;
BEGIN
  log_start('apex_get_pk');

  IF APEX_APPLICATION.g_request = 'COPY' THEN

    rv.emp_id := v(p||'COPY_EMP_ID');

  ELSE

    rv.emp_id     := nv(p||'EMP_ID');
    rv.version_id := nv(p||'VERSION_ID');
    
  END IF;

  log_end;
  RETURN rv;
EXCEPTION
  WHEN UTIL.application_error THEN
    log_end('application_error');
    RAISE;
  WHEN OTHERS THEN
    UTIL.log_sqlerrm;
    RAISE;
END apex_get_pk;

/*******************************************************************************
                               PUBLIC INTERFACE
*******************************************************************************/

PROCEDURE load IS
  p  VARCHAR2(10) := 'P' || UTIL.apex_page_id || '_';
  rv EMPS$TAPI.rvtype;
  r  EMPS$TAPI.rowtype;
BEGIN
  log_start('load');

  UTIL.check_authorization('Reporting');

  rv := apex_get_pk;
  r := EMPS$TAPI.get (emp_id => rv.emp_id);

  IF APEX_APPLICATION.g_request = 'COPY' THEN

    r := EMPS$TAPI.copy(r);

  END IF;

  apex_set (r => r);

  log_end;
EXCEPTION
  WHEN UTIL.application_error THEN
    log_end('application_error');
    RAISE;
  WHEN OTHERS THEN
    UTIL.log_sqlerrm;
    RAISE;
END load;

PROCEDURE val IS
  p             VARCHAR2(10) := 'P' || UTIL.apex_page_id || '_';
  rv            EMPS$TAPI.rvtype;
  dummy         VARCHAR2(32767);
  item_name_map UTIL.str_map;
BEGIN
  log_start('val');

  IF APEX_APPLICATION.g_request = 'CREATE'
  OR APEX_APPLICATION.g_request LIKE 'SAVE%' THEN

    rv := apex_get;

    UTIL.pre_val
      (label_map     => EMPS$TAPI.label_map
      ,item_name_map => item_name_map);

    dummy := EMPS$TAPI.val (rv => rv);
    
    UTIL.post_val;

  END IF;

  log_end;
EXCEPTION
  WHEN UTIL.application_error THEN
    log_end('application_error');
    RAISE;
  WHEN OTHERS THEN
    UTIL.log_sqlerrm;
    RAISE;
END val;

PROCEDURE process IS
  p  VARCHAR2(10) := 'P' || UTIL.apex_page_id || '_';
  rv EMPS$TAPI.rvtype;
  r  EMPS$TAPI.rowtype;
BEGIN
  log_start('process');
  
  UTIL.check_authorization('Operator');

  CASE
  WHEN APEX_APPLICATION.g_request = 'CREATE' THEN

    rv := apex_get;
    
    r := EMPS$TAPI.ins (rv => rv);

    apex_set (r => r);

    UTIL.success('Emp created.');

  WHEN APEX_APPLICATION.g_request LIKE 'SAVE%' THEN

    rv := apex_get;

    r := EMPS$TAPI.upd (rv => rv);

    apex_set (r => r);
    UTIL.success('Emp updated.'
      || CASE WHEN APEX_APPLICATION.g_request = 'SAVE_COPY'
         THEN ' Ready to create new emp.'
         END);

  WHEN APEX_APPLICATION.g_request = 'DELETE' THEN

    rv := apex_get_pk;

    EMPS$TAPI.del (rv => rv);

    UTIL.clear_page_cache;

    UTIL.success('Emp deleted.');

  END CASE;

  log_end;
EXCEPTION
  WHEN UTIL.application_error THEN
    log_end('application_error');
    RAISE;
  WHEN OTHERS THEN
    UTIL.log_sqlerrm;
    RAISE;
END process;

END EMPS$APEX;

Now, given the above package, we can create an Apex page that allows users to view, create, update, copy and delete a record from the EMPS table, using all the features provided by our TAPI.

  1. Create Page, select Form, select Form on a Table or view, select the table EMPS.
  2. Accept the defaults, or change them to taste, and click Next, Next.
  3. On the Primary Key wizard step, change type to Select Primary Key Column(s) and it should pick up the EMP_ID column automatically. Click Next.*
  4. For Source Type, leave the default (Existing trigger).** Click Next, Next, Next.
  5. For Branching, enter page numbers as required. Click Next, then Create.

* the Apex API and Table API generator also handles tables with no surrogate key by using ROWID instead; in this case, you would leave the default option selected (Managed by Database (ROWID)) here.
** note however that our TAPI will handle the sequence generation, not a trigger.

The page should look something like this:

Notice that it has created a Fetch Row from EMPS process for when the page is loaded, as well as the Process Row of EMPS and reset page processes for when the page is submitted. It has also created a few validations.

Notice also that all the items are named consistently with the column names; this is important as my Apex API package generator relies on this one-to-one mapping. You can, of course, add additional non-database items to the page – they won’t be affected by the generator unless the table is altered with columns that match.

Now, this page will work fine, except that it bypasses our TAPI. To change the page so that it uses our TAPI instead, edit the page as follows:

  1. Delete all the Fetch Row from EMPS, Process Row of EMPS and reset page processes.
  2. Delete all the validations.
  3. For all the page items, set Source Type to Null. In Apex 5 this is easy – just Ctrl+Click each item, then make the change to all of them in one step!
  4. Make the audit column items (CREATED_BY, CREATED_DT, LAST_UPDATED_BY, LAST_UPDATED_DT) Display Only.
  5. Make the VERSION_ID item Hidden.
  6. Under Pre-Rendering, add an After Header process that calls EMPS$APEX.load;.
  7. In the Page Processing tab, under Validating, add a validation with Type = PL/SQL Function (returning Error Text).
  8. Set the PL/SQL Function Body Returning Error Text to EMPS$APEX.val; RETURN null;.
  9. Set Error Message to “bla” (this is a mandatory field but is never used – I think this is a small bug in Apex 5).
  10. Under Processing, add a process that calls EMPS$APEX.process;.
  11. Set Error Message to #SQLERRM_TEXT#.

Run the page – you should find that it works just as well as before, with all the TAPI goodness working behind the scenes. Even the validations work, and they will point at the right items on the page.

But that’s not all! You can easily add a useful “Copy” function that your users will thank you for because (depending on the use case) it can reduce the amount of typing they have to do.

  1. Add a button to the region, named SAVE_COPY (this name is important) with the label Copy. Tip: if you want an icon set the Icon CSS Classes to fa-copy.
  2. Add a hidden item named after the PK item prefixed with “COPY_”, e.g. P14_COPY_EMP_ID.
  3. Under After Processing, add a Branch that goes to this same page (e.g. 14, in this example).
  4. On the branch, set Request (under Advanced) to COPY and assign &P14_EMP_ID. to the item P14_COPY_EMP_ID.
  5. Set When Button Pressed to SAVE_COPY.
  6. Change the order of the branches so that the Copy branch is evaluated before the other branches (see below)

Now, when they click Copy, the page will first save any changes they had made to the record, then go back to the same page with a copy of all the details from the original record. The user can then edit the new record and Create it if they so desire, or Cancel.

An advantage of this design is that, if you want to add a validation that applies whether someone is updating the table from Apex or from some other UI or interface, you can add it in one place – the TAPI (specifically, you would add it to the TAPI template). If you add a column, just add an item to the Apex page and regenerate the TAPI and Apex API. It’s a nice DRY-compliant solution.

Addendum: you may be wondering why we need a P14_COPY_EMP_ID item, instead of simply reusing the P14_EMP_ID item that’s already there. The reason for this is that after saving a copied record, in some cases we may want to copy some or all the child records from the original record to the copy, or do some other operation that needs both the old and the new ID.

Source code/download: https://bitbucket.org/jk64/jk64-sample-apex-tapi

Refresh Apex Calendar

calendarwithrefreshbutton.PNG
Sometimes it’s the simple little things that can add polish and make your Apex application shine. One simple little thing that you can do is add a Refresh button to improve the usability of your Apex 5 calendar. This makes it easy for the user to see recent changes on the database, e.g. if events had been added or changed since the page had last been loaded.

  1. Set the Static ID on the Calendar region (e.g. “eventscalendar“)
  2. Add an Icon button (Button Template = “Icon”) to the calendar region
  3. Set the button’s Static ID (e.g. “refreshbutton“)
  4. Set Icon CSS Classes to “fa-refresh
  5. Set Action to “Defined by Dynamic Action”
  6. (optional) Set Template Option -> Style to “Remove UI Decoration”
  7. Add a Dynamic Action to the button, Event = “Click”
  8. Set Fire on Page Load to “No”
  9. Add a True Action “Execute Javascript Code” with the code below:
$("#eventscalendar_calendar").fullCalendar("refetchEvents");

This calls the refetchEvents method of the FullCalendar object. Replace the “eventscalendar” part of the id with whatever static ID you set on the Calendar region in step #1.

Now, to add a bit of pizzazz you can get the refresh button icon to spin while the calendar is being refreshed. To do this, change the dynamic action code to this instead:

$("#refreshbutton span.t-Icon").addClass("fa-spin");
window.setTimeout(function() {
  $("#eventscalendar_calendar").fullCalendar("refetchEvents");
  window.setTimeout(function() {
    $("#refreshbutton span.t-Icon").removeClass("fa-spin");
  }, 1000);
}, 50);

This code starts the refresh icon spinning before invoking refetchEvents, then stops the icon spinning after it has completed. Note that these are done via timeouts (otherwise the icon isn’t repainted until after the entire javascript function has completed). I added a wait of 1 second prior to stopping the spinning because most of the time the refresh is too quick to notice the spinning effect.

You can, if it makes sense in your case, also make the calendar automatically refresh itself periodically, using some simple javascript: add the following function to the page Function and Global Variable Declaration:

function refreshCalendar() {
  $("#refreshbutton span.t-Icon").addClass("fa-spin");
  window.setTimeout(function() {
    $("#eventscalendar_calendar").fullCalendar("refetchEvents");
    window.setTimeout(function() {
      $("#refreshbutton span.t-Icon").removeClass("fa-spin");
    }, 1000);
  }, 50);
}

Then add this to start the timer in the page attribute Execute when Page Loads:

var periodicrefresh = setInterval(function() {
                                    refreshCalendar();
                                  }, 30000);

In this example, I’ve set the timer to go off every 30 seconds. Not only does it refresh the calendar, but the user gets feedback on what’s going on because the refresh button icon is spinning. Be careful not to set the timeout too low, or else your database could get very busy!

The function I’ve declared can now also be reused by the button’s dynamic action, so I can replace the DA javascript with simply:

refreshCalendar();