Export CLOB as a SQL Script #JoelKallmanDay

Quite often I will need to export some data from one system, such as system setup metadata, preferences, etc. that need to be included in a repository and imported when the application is installed elsewhere.

I might export the data in JSON or CSV or some other text format as a CLOB (character large object) variable. I then need to wrap this in suitable commands so that it will execute as a SQL script when installed in the target system. To do this I use a simple script that takes advantage of the APEX_STRING API to split the CLOB into chunks and generate a SQL script that will re-assemble those chunks back into a CLOB on the target database, then call a procedure that will process the data (e.g. it might parse the JSON and insert metadata into the target tables).

This will work even if the incoming CLOB has lines that exceed 32K in length, e.g. a JSON document that includes embedded image data encoded in base 64, or documents with multibyte characters.

This is clob_to_sql_script:

function clob_to_sql_script (
    p_clob           in varchar2,
    p_procedure_name in varchar2,
    p_chunk_size     in integer := 8191
) return clob is

-- Takes a CLOB, returns a SQL script that will call the given procedure
-- with that clob as its parameter.

    l_strings apex_t_varchar2;
    l_chunk   varchar2(32767);
    l_offset  integer;        

begin

    apex_string.push(
        l_strings,
        q'[
declare
l_strings apex_t_varchar2;
procedure p (p_string in varchar2) is
begin
    apex_string.push(l_strings, p_string);
end p;
begin
]');
    
    while apex_string.next_chunk (
        p_str    => p_clob,
        p_chunk  => l_chunk,
        p_offset => l_offset,
        p_amount => p_chunk_size )
    loop
        apex_string.push(
            l_strings,
            q'[p(q'~]'
            || l_chunk
            || q'[~');]');
    end loop;    

    apex_string.push(
        l_strings,
        replace(q'[
    #PROC#(apex_string.join_clob(l_strings));
end;
]',
            '#PROC#', p_procedure_name)
        || '/');

    return apex_string.join_clob(l_strings);
end clob_to_sql_script;

Note that the default chunk size is 8,191 characters which is the safe limit for multi-byte characters. You can choose a smaller chunk size if you want, although if the incoming CLOB is very large, the smaller the chunk size the bigger the expanded SQL script will be.

A simple test case will demonstrate what it will do:

declare
    l_input  clob;
    l_output clob;
begin
    l_input := q'[
{
    "data": "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
}
]';
    l_output := clob_to_sql_script(
        p_clob           => l_input,
        p_procedure_name => 'mypackage.import',
        p_chunk_size     => 60 );
    dbms_output.put_line( l_output );
end;
/

The above script would output this:

declare
l_strings apex_t_varchar2;
procedure p (p_string in varchar2) is
begin
    apex_string.push(l_strings, p_string);
end p;
begin

p(q'~
{
    "data": "Lorem ipsum dolor sit amet, consectetur adip~');
p(q'~iscing elit, sed do eiusmod tempor incididunt ut labore et d~');
p(q'~olore magna aliqua. Ut enim ad minim veniam, quis nostrud ex~');
p(q'~ercitation ullamco laboris nisi ut aliquip ex ea commodo con~');
p(q'~sequat. Duis aute irure dolor in reprehenderit in voluptate ~');
p(q'~velit esse cillum dolore eu fugiat nulla pariatur. Excepteur~');
p(q'~ sint occaecat cupidatat non proident, sunt in culpa qui off~');
p(q'~icia deserunt mollit anim id est laborum."
}
~');

    mypackage.import(apex_string.join_clob(l_strings));
end;
/

The source can be downloaded from here: clob_to_sql_script.sql


Protect your APEX app from URL Tampering – in just a few clicks

Recently I’ve been reviewing and updating my knowledge of APEX security, especially protection from URL tampering. I’ve read the documentation, a number of blogs, and heard from people with experience in the field such as Lino. By default, when you create a new application in APEX you get the following security settings set automatically, which is a good start:

  • Application Session State Protection is Enabled.
  • Each page has Page Access Protection set to Arguments Must Have Checksum.
  • Each Application Item has Protection Level set to Restricted – May not be set from browser.
  • Each Primary Key Item* created by a wizard has Protection Level set to Checksum Required – Session Level.

(* that is, any item mapped from a table column that is, or forms part of, a Primary Key constraint).

These default settings are considered best practice. If you change these, it becomes your responsibility to ensure that your application is protected against security vulnerabilities from URL tampering.

For page items, however, the Protection Level defaults to Unrestricted. This is ok for Form items because the page fetch process will set their values on page load, rendering any attempt at URL tampering ineffective.

For non-form page items, unless the Page Access Protection is relaxed (Unrestricted), leaving items unrestricted is safe since URL tampering is blocked for the entire page anyway. At runtime, if a malicious visitor tries to modify the item value via the URL, they will get the error “No checksum was provided to show processing for a page that requires a checksum when one or more request, clear cache, or argument values are passed as parameters.

Error message "No checksum was provided to show processing for a page that requires a checksum when one or more request, clear cache, or argument values are passed as parameters."

However, what if a developer later needs to change the page to Unrestricted? They may unwittingly introduce a potential URL tampering issue because one or more items were not protected.

UPDATE: in fact, this applies even if it’s a different page in the same application. As Martin D’Souza pointed out a decade ago, URL tampering for any item in the application is possible from any page in the application that is Unrestricted.

The majority of these items are editable input items, so the fact that someone may input a value via the URL is not a big deal. However, for Hidden and Display Only items, it is common for application logic to depend on their values; this logic may be adversely affected by malicious values supplied via the URL.

In some cases, this default is needed in order for the application to work. Some examples when an item must be left Unrestricted are:

  • An item is changed by a Dynamic Action (whether via a Set Item Value, via the Items to Return of a Execute Server-side Code action, or in some custom JavaScript), and cannot have Value Protected set because the page may be submitted.
  • We do actually intend the item to be set via the URL, e.g. when an external web page has a link that sets the item’s value.

In all these cases, the application must be designed to ensure it does not “trust” the value of these items; it should apply suitable checks to ensure the values are valid.

In most cases, it is best practice to set the item Protection Level to Checksum Required – Session Level (or Restricted – May not be set from browser where supported).

You can use a query like this to discover all items that may need to be reviewed:

select
    i.application_id,
    i.page_id,
    i.page_name,
    i.region,
    i.item_name,
    i.display_as
from apex_application_page_items i
where i.application_id = :app_id
and i.item_protection_level = 'Unrestricted'
and i.display_as_code in ('NATIVE_HIDDEN','NATIVE_DISPLAY_ONLY')
order by i.application_id, i.page_id, i.region, i.item_name;
Report showing APPLICATION_ID, PAGE_ID, PAGE_NAME, REGION, ITEM_NAME, DISPLAY_AS, listing two Display Only items (P1_DISPLAY_ONLY_ITEM, P1_DISPLAY_ONLY_ITEM_DA) and two Hiden items (P1_HIDDEN_ITEM, P1_HIDDEN_ITEM_DA) that have Item Protection Level set to "Unrestricted".

Other excellent options are using third-party security scanners such as APEXSec and APEX-SERT to alert you to potential issues in your application. We mandate the use of tools like these internally at Oracle for our own applications and they are a great help.

Using the Session State Protection Wizard

One easy step you can take right now is to use the Session State Protection wizard. It gives you a quick overview of what level of protection your application has against URL tampering, and gives an easy way of fixing the relevant attributes in bulk.

You can access the wizard via Shared Components > Session State Protection

Screenshot of part of App Builder Shared Components; under the Security heading, we want to click on "Session State Protection".

Alternatively, you can access the wizard via Edit Application Definition > Security > Session State Protection > Manage Session State Protection

Screenshot of part of the App Builder Edit Security Attributes page, under the Security tab. In the Session State Protection section, we want to click on the button "Manage Session State Protection".

The wizard starts by showing an overview of the current state of your application’s protection against URL tampering.

Screenshot of the App Builder Session State Protection overview page.
It indicates that my application has Session State Protection = Enabled.
It shows that one page is set to "Arguments Must Have Checksum", one page allows "No URL Access", and one page is "Unrestricted".
It indicates that all 9 Page Items in the application are set to "Unrestricted".
It indicates that of the application's Application Items, one is set to "Restricted - May not be set from browser", one is "Checksum Required - Session Level", and one is "Unrestricted".
Next to each category a ">" icon button is shown.
At the bottom of the page is the button "Set Protection".

You can see if your application has Session State Protection enabled (which it should, really), and if any pages, page items, and/or application items are unprotected. In my sample app here, it’s obvious that there are some potential security issues that need to be reviewed.

You can click the > buttons next to each category to list all the pages and items that need to be reviewed.

The main things to watch out for are Pages, Page Items, and Application Items that are set to Unrestricted. Other values are generally fine.

If you see any Items which are set to Checksum Required but not at the Session Level, you may find that a developer has simply set them incorrectly and you should consider changing them to Session Level. However, there are some scenarios where the other levels (Application Level, or User Level) are required.

Now, I might now go through the application page-by-page and set the protection level on each page and item as appropriate. This could be a laborious process for a large application.

A good alternative is to use this wizard to set the protection level in bulk. In this case, I’m going to click Set Protection.

Screenshot of page 1 of the Session State Protection Wizard.
It is asking to Select an Action - either "Disable", or "Configure". I have selected "Configure".
Buttons at the bottom of the page allow me to Cancel, or go to the Next page.
I’ve selected the action Configure, then click Next.
Screenshot of page 2 of the Session State Protection Wizard.
This page allows me to select the Page Access Protection (defaulted to "Arguments Must Have Checksum"), the Page Data Entry Item Protection, the Page Display-Only Item Protection, and the Application Item Protection. These last three are all defaulted to "Checksum Required - Session Level".
Buttons at the bottom of the page allow me to go to the Previous page, Cancel, or go to the Next page.
The wizard now gives me the opportunity to modify the protection level on my pages and items in bulk. I’m going to accept the defaults (Arguments Must Have Checksum / Checksum Required – Session Level) because they are appropriate for most cases in my application.
Screenshot of the last page of the Session State Protection Wizard.
This allows me to confirm the changes that will be made to pages and items in the application.
Buttons at the bottom of the page allow me to go to the Previous page, Cancel, or Finish.
After reviewing the summaries of the changes that the wizard will make, I click Finish.
Screenshot of the App Builder Session State Protection overview page, after running the wizard.
The page now indicates that all 3 pages in my application are set to "Arguments Must Have Checksum", that all 9 Page Items and the 3 Application Items are now set to "Checksum Required - Session Level".

Perfect!

Final Steps

Now, I need to check for hidden page items that are now restricted that might need to be returned to Unrestricted. Otherwise, users will see the error “Session state protection violation” when they submit the page, if a dynamic action has changed them.

Screenshot of an error message alert, saying "1 error has occurred: Session state protection violation: This may be caused by manual alteration of protected page item P1_DISPLAY_ONLY_ITEM_DA. If you are unsure what caused this error, please contact the application administrator for assistance."

The following query will alert me to any Hidden items that have Value Protected switched off (e.g. because they need to be submitted):

select
    i.application_id,
    i.page_id,
    i.page_name,
    i.region,
    i.item_name,
    i.display_as
from apex_application_page_items i
where i.application_id = :app_id
and i.item_protection_level != 'Unrestricted'
and i.display_as_code = 'NATIVE_HIDDEN'
and i.attribute_01 = 'N' -- Value Protected
order by i.application_id, i.page_id, i.region, i.item_name;
Report showing APPLICATION_ID, PAGE_ID, PAGE_NAME, REGION, ITEM_NAME, DISPLAY_AS listing one entry for "P1_HIDDEN_ITEM_DA", a hidden item that is set to "Unrestricted" and has attribute_01 (Value Protected) set to "N".

Now I can review this item to check if Value Protected really needed to be switched off. If the page is never submitted, or the item is never changed by any dynamic actions, this could be switched On. Otherwise, I need to set the item protection to Unrestricted in order for the page to work.

Having made changes to the application, I need to test to ensure I haven’t introduced any issues. My focus will be mainly on the following areas:

  1. Navigation – e.g. do the View or Edit buttons in all reports still work?
  2. Dynamic actions – e.g. do all the dynamic actions and custom javascript still work on all pages that set item values?

For #1, I’m looking for any links that include item values that were not correctly built. If the application generates any links using just string concatenation, it will fail if the target page expects a checksum. The application should build these links using declarative link attributes if possible, or by calling apex_page.get_url (or apex_util.prepare_url at least).

For #2, I would test to ensure that after triggering a dynamic action or javascript code that modifies an item’s value, that the form is still submitted (saved) without error.

Further Reading

Thanks to Christian Neumueller for his review and comments on this article.


Reusable Region as a Modal Page

"clone" icon

On a number of pages throughout my application, I needed to build a region containing a fairly complex set of items, along with dynamic actions and other controls to provide a friendly editing experience for the user. This non-trivial set of items with their accompanying dynamic actions and conditions would be needed on several different pages, and in some cases, multiple times on the same page.

Copying all this all over the place would have created a maintenance headache, so I would much prefer to build them only once, and then re-use the same component throughout my application. Unfortunately, APEX does not at this stage support the concept of a reusable region. An idea might be to allow a region to “subscribe” to another region – although this would be tricky because somehow the item names, dynamic action names, etc. would need to be unique but predictable.

Why not use a plugin?

One approach is to build the whole region as a plugin; this would be ideal as the plugin can then be maintained separately and deployed wherever it’s needed; this would have the benefit that it could be reused in multiple applications.

The downside is that I would not be able to use the declarative features of APEX to define the items and dynamic actions within the region; I would have to code most of that in custom HTML, JavaScript and AJAX calls for database interaction. This would then provide a different maintenance challenge for my successors.

Why not put the region on the Global Page?

Another approach would be to build the region on the Global Page; a condition could be used to show it if it’s needed by the current page.

The downsides to this approach include: (a) you can’t reuse it multiple times on a single page; (b) it may be tricky to integrate it on the pages it needs to return data to (although this could be done with some JavaScript); and (c) you have little control over where on each page the region would be shown.

The Global Region idea might work better if is implemented as an Inline Dialog; with some JavaScript it could be made to pop up wherever it’s needed. I haven’t tried this approach, however.

Use a Modal Page

Instead, the approach I took was to use a modal page. This is a page that will pop up as a layer on top of the calling page, making the calling page visible but non-responsive until the user closes the popup. I can then define all the items needed, along with their conditions and dynamic actions, in the one modal page, and then add buttons throughout my application wherever it was needed.

The calling page needs to pass the current value of one or more items to the modal page; these values are not in the database (yet) because the user may be in the middle of editing them, so their current value on screen may be different to the value stored in the table. This means I can’t have the modal page reading the value from the table, and I can’t just pass the value using the link attributes because these are set in stone when the page is rendered.

In order to open the modal page, then, I need to use a dynamic action.

Note that you can’t build the URL for the modal page in JavaScript, because the client-side code cannot calculate the checksum required by the modal page. Instead, I pre-calculate the URL for the modal page using apex_page.get_url which generates the checksum automatically.

When the user clicks the “Edit” button, it needs to first copy the current value of the item into the session state for the modal page; I do this by making the Edit button Defined by Dynamic Action. On click, it executes two actions: (1) Server-side Code to submit the current value of the text item and set the modal item’s value; then (2) JavaScript Code to redirect to the URL I calculated earlier.

The modal page is then shown, allowing the user to make changes to the value. When they click the “OK” button, the modal page closes and returns the value via Items to Return.

Note that the modal page itself never saves any changes to the database, since on the calling page, the user might decide to cancel.

Back on the calling page, the new value is copied back into the page item via a Dialog Closed dynamic action. This sets the value based on the Dialog Return Item.

I’ve built a “dummy” sample app to demonstrate this technique. You can try it out, and download the sample app definition, from here: https://apex.oracle.com/pls/apex/jk64/r/demo-reusable-modal/home

Details

Here is my main page definition, with two regions. Each region has an item that we want to pass to/from our modal page.

Page designer showing two regions defined, "Region 1" and "Region 2"

Each region needs a unique Static ID.

Page designer showing the Static ID for "Region 1" is set to "region1"
Page designer showing the Static ID for "Region 2" is set to "region2"

Each region has a visible Value item, an Edit button, and a hidden item to precalculate the URL for the modal page.

Page designer showing Region 1 has an item "P1_VALUE1", a button "EDIT1", and a hidden item "P1_EDIT_URL1". Region 2 similarly has an item "P1_VALUE2", a button "EDIT2", and a hidden item "P1_EDIT_URL2".

There are no special attributes on the value item(s); they could be a simple text field, a text area, a readonly item, a combination of various item types, or they could be hidden. Typically they would be based on database column(s) and saved in the record being edited.

The “EDIT URL” hidden items are precalculated using an expression, and set to Always, replacing any existing value in session state.

Page designer showing the PL/SQL Expression as the source for P1_EDIT_URL1.

The other edit URL is similar.

Page designer showing the PL/SQL Expression as the source for P1_EDIT_URL2.

The call to apex_page.get_url is used to pass some static values (that are not changed by the page at runtime) to the modal page. These values may be used by the modal page to customise it for the context it was called from.

apex_page.get_url(
    p_page => 'modal',
    p_items => 'P2_ID,P2_OPTION',
    p_values => :P1_ID || ',' || 'Region 1',
    p_triggering_element => '$(''#region1'')'
)

Note that the value of the item is not passed in the URL.

Note that p_triggering_element is a string, constructed to be a jQuery selector referring to the Static ID that was set on the region, so that the right Dialog Closed event will fire (since we may have multiple Edit buttons on the same page).

Tip: if your modal page doesn’t need them, you can omit the p_items and p_values parameters.

The Edit buttons are set to “Defined by Dynamic Action“.

Page designer showing EDIT1 with a dynamic action "on click edit1".

The Server-side Code simply copies the current value of the item into the modal page’s item. This sets the session state on the server, which is then loaded when the modal is opened.

Page designer showing the Execute Server-side Code action runs the code ":P2_VALUE := :P1_VALUE1;", with Items to Submit set to "P1_VALUE1".

The JavaScript Code redirects to the modal page using the URL we calculated on page load.

Page designer showing the Execute JavaScript Code action.
apex.navigation.redirect("&P1_EDIT_URL1.");

The JavaScript Code for Region 2 is the same except it refers to P1_EDIT_URL2.

On page 2, the modal page, I have contrived an example “calculator” which simply breaks the string value into two “parts”, and allows the user to edit each “part” separately; when they click OK, the concatenated value gets returned to the calling page.

Page designer for page 2 ("modal"). It has two editable items "P2_PART1", "P2_PART2", as well as a "hidden items" region with "P2_VALUE", "P2_ID" and "P2_OPTION". The page also has a button region with "CANCEL" and "OK" buttons.

The two “PART” items are calculated on page load with some PL/SQL:

The page has an After Header process "init" which computes some value for P2_PART1 and P2_PART2 based on the value of P2_VALUE. (The expression itself is not important.)

Note that this code is being executed based on the value of P2_VALUE which was set in session state by the calling page.

Just for the sake of the demo, my “calculator” merely sets the value of the hidden P2_VALUE item based on concatenating the two “parts”:

Dynamic action on change of P2_PART1 and P2_PART1 executes some JavaScript which sets the value of P2_VALUE based on the entered values of P2_PART1 and P2_PART2.

Note: you would define whatever items, dynamic actions or other components that you need.

This modal page never saves any changes to the database; that’s the role of the calling page.

The OK button simply closes the dialog, returning the new value of P2_VALUE to the calling page.

Page designer showing the "on Click OK" dynamic action. It runs the Close Dialog action. The Items to Return is set to P2_VALUE.

Back on the calling page, each region has a dynamic action defined on Dialog Closed.

Page designer on page 1, within Region 1, a dynamic action "on close modal1" on the event Dialog Closed.

The Set Value action copies the Dialog Return Item value into the appropriate item on the page.

Page designer on page 1, the "on close modal1" dynamic action runs a Set Value to set the item P1_VALUE1 to the Dialog Return Item, P2_VALUE.

Summary

To use my special modal page in my application, I need to:

  1. Set a unique Static ID on the region
  2. Add an Edit button with a dynamic action
  3. Add a hidden URL item based on an expression
  4. Add a dynamic action to the region on Dialog Closed

The outcome is that the modal page provides a user-friendly experience involving any complex items, lists, dynamic actions, conditions, etc. maintained in one place, which can be re-used anywhere needed in the application.

If you would like to examine in detail the demo app, you can download it from here: https://apex.oracle.com/pls/apex/jk64/r/demo-reusable-modal/home (click the “Download this demo app” link). You may then install this in your own workspace and check out how it all works.

Have you had a similar requirement in your apps? Comment below and describe how you implemented it.


I didn’t change anything… yet I get “Unsaved changes”?

I had an APEX page based on a Form region that I’d built by hand (rather than using the wizard). I was wondering why the user always got an unexpected warning “Changes that you have made may not be saved.” – even though they hadn’t changed anything on the page.

I found Martin D’Souza’s article How to Find Which Item has Been Changed in APEX and ran the code in the browser console. This pointed me to a single item and I had a closer look at it.

I noticed that the item had a List of Values, and it had the Display Null Value setting set to No; however, the value in the underlying column was NULL. What was happening was that the item could not handle a null value, so it was changing to the first value in the LOV; this in turn marked the item as “changed” which caused the “unsaved changes” warning to show when the user tries to navigate away from the page.

When I set Display Null Value to Yes, the problem was resolved. Alternatively, I could have ensured that the underlying column would always have a value (e.g. by putting a NOT NULL constraint on it), which would also have resolved this problem.


APEX Map Region vs. Google Map Plugin

Within the APEX development team it has been known for some time that maps are frequently required and this has been on the roadmap to be built in to the core product.

Since 2016 I have built and maintained plugins that make it easy to integrate Google Maps in your APEX applications. The most popular of these is the ReportMap Plugin which has received a wealth of features and enhancements, and is being used widely.

Introducing: Map regions

In the latest pre-production release APEX 21.1 which you can try today for yourself at apex.oracle.com, the APEX development team has introduced the new Map region. This component allows the developer to show a world map on the page, and add one or more “Layers”, each based on a table or SQL query, to show features on the map.

This is a welcome move because it means maps will be easy for all APEX developers to use, including those who avoid plugins (e.g. due to the lack of direct support from Oracle). It also means that maps added to applications based on the core feature will be fully supported in future releases of APEX without needing to rely on a 3rd party.

Note: this post is based solely on my first impressions of the new feature and is not intended to answer all questions about it. There will be more official blog posts coming directly from the APEX development team about this and other new features being introduced in APEX 21.1, so keep a look out for those!

The APEX Map region renders the map using the MapBox API, with a number of tile backgrounds included based on OpenStreetMap and HERE map data.

Implementing a Map Region

Let’s try the new Map region, and compare it to the jk64 ReportMap plugin. To add a map to a page, I added a region of type “Map” and nominated a data source for the Layer to show on it.

First thing you might notice is what I didn’t need:

  • no 3rd party plugin to install
  • no account on a 3rd party cloud service
  • no API key, and no APIs need to be enabled
  • no credit card details

The Map region is free to use within your applications, just like any other built-in feature of APEX.

If you already have a map based on the ReportMap plugin, you can if you wish convert it to a map by simply changing the region Type to Map – the SQL data source will be preserved and you can use the same query for the new Map region type. However, the danger with this approach is that you may lose some attributes and customisations that you had on the plugin region. Instead, I recommend using the Duplicate feature to create a copy of your map region, change the attributes on the copy, using the original as a reference as you go. Once you’re happy with the new map you can then delete the original plugin region.

You can choose to set the data source directly on each Layer (e.g. if you want to get data from multiple data sources), or you can set the data source on the map Region. If you set it on the Region, each Layers may refer to the Region data source by setting the layer’s Location attribute to Region Source.

If you have a single data source that you want to split up into multiple Layers, you can set the Row Assignment column which will be used to differentiate the data for each layer. This would be more efficient than adding separate SQL queries for each layer if the queries are based on the same table or view.

The first thing I noticed when converting my demo application was that since my data source was based on an APEX collection, the Lat and Lng columns are strings, not numbers; to use this as a data source for the Map region I had to convert the strings to numbers first using TO_NUMBER.

Once that was done, I could map the LAT and LNG columns to the layer by setting the Geometry Column Data Type to Longitude/Latitude:

Notice that the layer may alternatively be based on a SDO_GEOMETRY column, or a GeoJSON geometry object.
Layer attributes

This is the result:

I wanted to style it as close as possible to my plugin demo so I tweaked a few attributes on the Region:

  • Appearance / Template Options / Remove Body Padding = on
  • Region Attributes:
    • Background = Custom
    • Standard (tile background) = Oracle World Map
    • Height = 350
    • Controls / Options / Mousewheel Zoom = on
    • Legend / Show = off
  • Layer Attributes:
    • Point Objects / Shape Scale = 1.5
    • Appearance / Fill Color = #e21818 (reddish)
    • Tooltip / Column = NAME
    • Info Window / Title Column = NAME
    • Info Window / Body Column = INFO

Much nicer colours, in my humble opinion 🙂

Map Dynamic Actions

The next thing I need to do is handle click events on the pins. To do this, I added a Dynamic Action to the map region, on the event Map Object Clicked.

Notice that the Map region can trigger the following events:

  • Map Initialized – the map has loaded, including all the data
  • Map Changed – the user pans the map or zooms in or out
  • Map Clicked – the user clicks in the map area (but not on a pin)
  • Map Object Clicked – the user clicks on a pin

Whenever I’m experimenting with dynamic actions one of the first things I’ll add is a Action to run this JavaScript:

At runtime in debug mode, the console log will then show the content of this.data which shows the structure it takes.

Based on this, I can see that we get the id, infoWindow, lat, lng, and tooltip attributes – similar to the structure provided by the ReportMap plugin events. If I want to display the Latitude and Longitude values on the page, I create a display-only item (e.g. P1_POSITION), and add a “Set Value” action to the dynamic action as follows:

When a pin is clicked, we now see this data on the page:

Of course, we could make this item hidden if we want, and use its value in other ways.

The Map Clicked event returns this.data.lat and this.data.lng to indicate where the user clicked.

The Map Changed event returns:

  • this.data.changeType – e.g. ‘map-resized’, ‘map-drag’, ‘map-zoom’
  • this.data.bbox – bounding box, an array of numbers of longitudes and latitudes [west, south, east, north]
  • this.data.layers – an array with attributes for each layer (id, name, visible)
  • this.data.bearing
  • this.data.pitch
  • this.data.zoom

New Features

The following is a short list of features or enhancements that the new Map region has, which are not (currently) supported by the ReportMap plugin:

  • Multiple data layers, each with their own distinct data source; you can also use one SQL query for multiple layers if you want
  • REST data sources
  • Declarative styles – options for customing how each data layer is rendered, including pin and feature icon, colour and size
  • Min/Max Zoom – each layer can be shown or hidden automatically depending on the zoom level (e.g. show a more detailed layer as the user zooms in)
  • Legend – each data layer (optionally) can be shown in a legend, allowing the user to selectively show/hide each layer
  • Extruded polygons – show a 3D polygon rising from the ground with the height determined by a column from your data source
  • Initial Position and Zoom is remembered between page requests
  • Circle tool – allows the user to draw a circle on the map; you can then respond to this by filtering data by points that fall within the circle
  • Distance tool – allows the user to calculate the distance between two points

Conclusion

That’s page 1 of my side-by-side demo done. Not too shabby!

Only 34 other pages to go over… eventually I plan to release my demo application for you to play with. Some of the demo pages will not be so easy or even possible to replicate, however, until we get the ability to use the Google Maps JavaScript API in the native Map region – so they’ll need to wait for some potential future release.

More posts to come…

Q: Should we switch now, or wait?

If you have a simple map on your page showing some pins, with no custom JavaScript code that provide specific custom behaviour, I think you should consider switching now. Of course, you should make sure to test the new region thoroughly – as with any major new feature, there will be a few bugs here and there. Overall however the Map region looks solid so far and is based on a well-known open source API with a long history.

One of the things to remember if you’re planning to switch from the ReportMap plugin to the new Map region is that not every feature is implemented the same way, and some features are not available at all (at least, not yet, if ever). This is partly because they are based on different JavaScript APIs (Google Maps vs MapBox). In addition, some UI behaviour is different and will likely always be different, although a lot of it will be customisable.

Q: Is this the end for the JK64 ReportMap plugin?

No, the ReportMap plugin is not going away any time soon. I plan to enhance and support it for years to come. My intent is to continue supporting the plugin at least until the APEX Map component supports integration of the Google Maps JavaScript API, and provides declarative support for most (ideally, all) of the declarative features of the ReportMap plugin. I expect that after this, most developers will naturally choose the native Map region over the plugin for new projects, and I’ll only need to provide bug fix support for the plugin while existing users of the plugin migrate gradually to the new component.

I consider this one of the strengths of the plugin system: the APEX development team will never have the capacity to support every last feature needed for every last application built for any customer in the world, so developers and companies should be empowered to create and use plugins to fill those gaps.

These plugins often serve to prove there is demand and need for a particular feature, and this often prompts the APEX development team to consider building these features into the core product, making it better with each release. Exciting times are ahead of us.


ReportMap Release 1.5

The latest version of the ReportMap APEX plugin is now v1.5.

The plugin now supports Overlays, which allows you to add almost any arbitrary HTML or image content to particular points on the map. For example, instead of showing the default red pin, you might want to show a pretty Information card at a location. The cards are clickable as well, and you can use a dynamic action to make your app respond however you wish.

You can even show an image as a map overlay, which will be scaled automatically as the user zooms and pans the map.

In the previous release I added a companion Dynamic Action “Action” plugin that allows you to declaratively perform actions on the map. This release fixes a few bugs in that plugin, and also adds a new, second companion Dynamic Action plugin: Show Directions. This plugin allows you to invoke the Directions API on the map between one location and a destination without needing to write JavaScript. The locations may be specified with static values (lat,lng coordinates or addresses), from items on your page, JavaScript expressions, or jQuery selectors. The travel mode (e.g. driving, bicycling, etc.) can also be specified the same way.

You can review the full list of changes and download the plugin from here: https://github.com/jeffreykemp/jk64-plugin-reportmap/releases/tag/v1.5


Speaking at AUSOUG 2021

The Australian Oracle User Group is hosting a series of webinars this year and on 17 February I’ll be speaking about how to add an interactive Google Map to your APEX application. If you’re using APEX and want to see how easy it can be to integrate Google Map capabilities into your application, this is for you.

My session is at 9am in Perth time (1am UTC) – which is:

  • 6:30am in India
  • 9:45am in Eucla
  • 10:30am in Darwin
  • 11am in Brisbane
  • 11:30am in Adelaide
  • 12pm in Sydney, Melbourne, Canberra and Tasmania
  • 2pm in New Zealand

For more information about the AUSOUG National Webinar Series, go to: https://ausoug.org.au/home/2021-webinar-series/national-webinar-series-2021/

To register for this session, go to: https://register.gotowebinar.com/register/6201790250674031374


ReportMap Release 1.4

Release 1.4 of the JK64 Report Google Map R1 has been released with a number of bug fixes and enhancements. You can review the changes here: https://github.com/jeffreykemp/jk64-plugin-reportmap/releases/tag/v1.4. The most important enhancement is a new Dynamic Action plugin that is included as a recommended companion to the map plugin.

The Dynamic Action plugin, called JK64 Report Google Map R1 Action, allows you to implement any of a range of custom behaviours on your map region. If installed, you can make the map respond to user behaviour or other events without needing to resort to writing your own custom JavaScript.

You can add a dynamic action to modify a variety of options and attributes of the map, execute searches, pan and zoom, load features via geoJson, and more – and these can be based on the value of items on your page, or via JavaScript expressions that you specify.

For example, on the demo Plugin Options, the user can change the map type:

This is implemented as a radio item with a dynamic action on the Change event:

The dynamic action has the following attributes:

Note that in this case, it sets an Option – Map Type, based on the triggering element (the P28_MAP_TYPE item). The Affected Elements is required, and must refer to the map region that we want to change.

Notice anything missing? That’s right – No Code needed!

The plugin makes it easy to customise which of the default Google Map controls (buttons, etc.) are shown to the user:

  • Full Screen control
  • Map Type control
  • Rotate control
  • Scale control
  • Street View Pegman control
  • Zoom control

Other options that can be set include:

  • Clickable Icons
  • Disable default UI
  • Gesture Handling
  • Heading
  • Keyboard shortcuts
  • Map Type
  • Maximum Zoom level
  • Minimum Zoom level
  • Restrict search to Country
  • Styles
  • Tilt
  • Zoom level

In addition, the plugin allows you to restrict the map to a set of bounds, via the Restrict to Bounds or Restrict to Bounds Strict Mode actions.

You can browse all the possible actions in the WIKI: https://github.com/jeffreykemp/jk64-plugin-reportmap/wiki/DA-Plugin-Attributes-Reference


Another enhancement included in this release is explicit support for the Table / View data source. This is simple to use, although not quite as flexible as the SQL Query option. Your table or view must include columns with the correct column names expected by the selected Visualisation – for example, if your Visualisation is Pins, the table or view must have columns named lat, lng, name and id. Click the Help tab on Table Name for more details, or review the WIKI (https://github.com/jeffreykemp/jk64-plugin-reportmap/wiki/SQL-Query-Examples).


NOTE: the plugin supports APEX 18.2 and later. It is no longer planned to include backports for older versions of APEX.


A big thanks to many APEX developers around the world who have installed and used the map plugin over the years. Your suggestions, questions and bug reports have contributed a great deal to improving the plugin.


Saved Interactive Reports, Lost and Found

Sometimes we can too quickly say “No” when we should take a moment to think about whether we can actually say “Yes”. This was one of those times for me.

We had just gone live with a fairly big system move + upgrade – a suite of APEX applications shifted from one database instance running APEX 5 to another instance running version 19.1. The migration went smoothly. After the new instance was released to the business to do some final shakedown testing, they noticed one problem:

“All our saved reports are gone.”

Oops. We had built the new instance by simply importing each application from source control; since these scripts don’t include the Saved Report formats that users had customised in many of the Interactive Reports in prod, they didn’t get migrated to the new database.

When they asked if we can transfer the saved reports across, I initially replied, “Sorry, we can’t” – thinking that redoing the migration from scratch with a full export from the old database, followed by re-doing all the app changes, was going to take too much time and effort.

A minute later, I sent another email. “Hold that thought – there is a way.” I’d forgotten that my script for exporting the applications uses an APEX API with some parameters that until now I’d rarely used, but which would solve our problem. My script included this:

wwv_flow_utilities.export_application_to_clob (
    p_application_id => 100,
    p_export_ir_public_reports => 'N',
    p_export_ir_private_reports => 'N',
    p_export_ir_notifications => 'N');

NOTE: on more recent versions this API became supported as apex_export.get_application.

In order to restore all the user saved reports, I created a new version of my export script, but changed all the “N”s into “Y”s:

wwv_flow_utilities.export_application_to_clob (
    p_application_id => 100,
    p_export_ir_public_reports => 'Y',
    p_export_ir_private_reports => 'Y',
    p_export_ir_notifications => 'Y');

I call this the “Yes” script. Using this “Yes” script, we performed the following steps:

  1. Log into the schema on the old database
    (we hadn’t shut it down yet, thankfully – we’d just locked the schemas and set all the applications to “Unavailable”)
  2. Run the “Yes” script.
    Rename the resulting export files, e.g. f100_ir.sql, f110_ir.sql, etc.
  3. Log into the new database.
  4. Run the IR scripts (f100_ir.sql, etc.).
    This reverted all the applications to their old versions, but they included all the user’s saved reports.
  5. Re-import the new versions of the applications from source control.
    This upgraded all the applications, leaving the user’s saved reports intact.

Problem solved.


ReportMap Release 1.2

Version 1.2 of the ReportMap Google Map plugin has been released today. While the rest of you have been idling away under Covid-19 restrictions, I’ve been happy as a clam working on some exciting enhancements to the plugin.

If you just want to get in and have a play, check out the demo on apex.oracle.com.

New Features in this Release

Included in this release are the following new features:

  • New visualisation: Spidifier
  • Show turn-by-turn Directions
  • Customise each Marker with your own JavaScript function
  • Load large data sets in batches
  • Show spinner while data is loading
  • Localisation options

A bug when the new Friendly URLs feature of Oracle APEX 20.1 is used with the Clustering visualisation has also been fixed in this release.

The full list of enhancements and bugfixes, with links to the issues register, may be viewed here.

If you use the Directions or Route Map options, you can now show the turn-by-turn directions on your page, anywhere you want.

The documentation has been updated. The plugin now has four new plugin attributes, as well as a number of other attributes that can be set via JavaScript (the officially supported ones are documented on the plugin attributes page). Three new plugin events have also been added to support the new features.

Spiderfier

If you have a map that needs to show a lot of pins, especially ones that are close together, the plugin previously had the option of Clustering them at high zoom levels. The user could click on a cluster to zoom in enough to show the individual pins. One weakness of this approach is that if one or more pins are almost (or exactly) overlapping, the cluster never “unclusters” – the user cannot zoom in far enough to get the pins to show individually.

This release provides another Visualisation option, Spiderfier. This uses the OverlappingMarkerSpiderfier to control how pins react when clicked. When the user clicks a pin that is close or overlapping with other pins, it shifts the pins in that area into a ring, or a spiral (depending on how many pins are there) with lines pointing back to their original location. It also colours them blue to indicate they’ve been “spiderfied”. The user can then hover and click each marker separately.

If the user zooms in, the Spiderfier automatically returns all the pins to their original location.

I think the defaults I’ve set work reasonably well. If needed, you can customise the Spiderfier by setting its options via the JavaScript Initialisation Code (refer to “spiderfier options” here for details). You can also provide your own formatting function to change how the markers look when they are “spiderfied”.

Marker Icons

The WIKI has been augmented with a handy guide to Map Icons. The plugin has long supported the ability to specify custom images for the marker icons. This release gives a whole lot more control over the markers to the developer:

If all the icons in the query are being loaded from the same location, you can now set the iconBasePath option once and just have a relative icon file name in the query. When there is a lot of data to show in the map, this can significantly reduce the volume of data loaded to the client, which can lead to a significant performance improvement.

The developer can now supply a custom JavaScript function (via the markerFormatFn option) to format each marker using whatever logic they need.

For example, if the marker icon needs to be different according to some data value, you can send the data via one of the flex fields, and then write your custom function to set the marker icon depending on the value of the flex field.

You could also modify other characteristics of the marker, such as the title (hover text), info text (popup window), icon anchor point, opacity, and even position (although usually I’d expect your query would provide the correct lat/lng coordinates).

If you have a large number of custom icons you wish to use, along with a large data set of pins to render on the map, you could even compile the icons into a single sprite map to reduce network overhead. This means the image file is loaded once to the client, and then the map “cuts out” bits of the sprite map to render the marker icons. This can be done by setting just a few attributes of the marker’s Icon object. I haven’t tried it myself yet, but this tool looks like it would be useful for this purpose.

Loading Large Datasets

This release adds the Show Spinner and the Rows Per Batch attributes. These attributes are independent of each other, and they help to improve the quality of the experience for your end users when you are rendering a large number of pins on the map.

By default, new maps will have Show Spinner set on. For any existing maps, after upgrading you can turn this option on by setting it in the plugin attributes. This option causes the map to show the default APEX spinner while the data is loaded. The spinner is then removed when the last marker has been rendered. The effect is to give the user an indication that the map is “working”, and gives them immediate feedback when the data has finished loading and they may now interact with the map.

If the spinner seems to stay forever, it may indicate an issue with connectivity to the server (or perhaps that the server is under severe load or has stopped responding to requests).

When the APEX page has been rendered on the client, the Google Map is shown but the data is not immediately loaded; instead, a separate AJAX request is sent to the server to run your query and download all the data to render the pins on the map. By default, this is all done in one single AJAX call, which is the fastest way to get from start to finish; the downside is that the user will not see any pins on the map until all the data has been downloaded. You can change this behaviour by setting Rows Per Batch to some number (e.g. 1000). With this attribute set, the plugin will send a series of AJAX calls to the database (one at a time) and get a batch of records at a time. After loading a batch, the plugin will render the pins on the map (and if necessary, it will pan / zoom the map to show them all) and then send another AJAX request to get the next batch. When it has finished receiving all the batches, it adds any finishing touches needed (e.g. for a visualisation) and returns control to the user.

The advantage of this approach is that the user can see the pins being shown gradually, and they will know that “something is working”. This may help to give them a nicer user experience.

The downside of this approach is that it may cause a bigger load on the server (because each AJAX request requires running a new query, with an offset) and will usually take longer from start to finish. Generally, if your data comprises only a few hundred records at most, you will probably want to leave the Rows Per Batch setting blank.

The Future

There are still a few little enhancements on my “todo” list, but I’m keen to hear how you are using (or perhaps planning to use) this plugin, and if there are any new features or improvements that you need or want. If so, please raise them on the GitHub Issues page.

Quite a few people have raised questions or ideas in the past and sometimes I’ve incorporated them straight away, and other times it’s taken a little longer but I get there eventually. If you’re keen to contribute, feel free to have a poke around in the code and perhaps even do a pull request on the GitHub source to suggest a change. It would be great to collaborate with you because everyone has something unique to offer.

Long-term, I’m watching with interest the future direction of Oracle APEX. I remember at one point they were talking about incorporating some sort of new map region into the product, although the mention of this seems to have been dropped from the Statement of Direction (or maybe my memory is misleading me). I guess time will tell.