Got a lot of APEX applications, and/or a schema with lots of objects?
Not sure exactly what database objects are used by which application?
Not sure dropping a particular schema object might break something in your application?
Not sure if all the SQL and PL/SQL in every page of your application still runs without error?
If your answer to any of the above is “Yes”, you may be interested in a new API that has been added in APEX 24.1.
You can use this API to scan your application for any references to any schema objects, whether it refers to objects in a region, SQL queries, PL/SQL processes, and even plugins. Run this in your workspace, giving it the ID of an application you want to scan:
begin
apex_app_object_dependency.scan(p_application_id => :app_id);
end;
This scans through the whole application by generating a small temporary procedure that tests each schema object name, SQL, or PL/SQL. As it goes, it checks that the code compiles without error, and if it compiles, it saves a list of dependencies detected by the database including tables, views, stored functions and procedures, packages, and synonyms. It drops the temporary procedure at the end.
Depending on how big your application is, the scan may take some time to complete (e.g. 30 to 60 seconds) due to the time required to compile and analyze each temporary procedure. If you find it gets stopped prematurely due to a timeout error, you can run it in the background (for example, I like to use an “Execution Chain” process in an APEX application with “Run in Background” enabled).
Note that none of your application code is actually executed, so there should be no side effects of running the scan. However, if your database has any DDL triggers, they may fire as the temporary procedure is created and dropped.
Viewing the Scan Results
Once the scan is complete, you can query the results at your leisure by querying these views:
APEX_USED_DB_OBJECTS
APEX_USED_DB_OBJECT_COMP_PROPS
APEX_USED_DB_OBJ_DEPENDENCIES
APEX_USED_DB_OBJECTS
This lists each schema object that is used at least once in your application.
select
referenced_type, referenced_owner,
referenced_name, referenced_sub_name,
usage_count
from apex_used_db_objects
where application_id = :app_id;
Note that “USAGE_COUNT” is the number of distinct component properties that refer to the schema object; if a single component (e.g. a Process) refers to an object multiple times, it will only count as one usage.
If your database package is compiled with PL/Scope enabled, the dependency analysis will also report fine-grained dependencies on the functions, procedures, and other components within the database package.
APEX_USED_DB_OBJECT_COMP_PROPS
This lists each component property in your application that references at least one schema object.
select
page_id,
component_type_name, component_display_name,
property_group_name, property_name
from apex_used_db_object_comp_props
where application_id = :app_id;
You can also include the column CODE_FRAGMENT to show the object name, SQL or PL/SQL that was analyzed.
If a component property cannot be analyzed due to a compile error (e.g. if an expected database object is missing) the same view will tell you what the compile error was, which may help you to determine what’s gone wrong.
select
page_id,
component_type_name, component_display_name,
property_group_name, property_name,
code_fragment, error_message
from apex_used_db_object_comp_props
where application_id = :app_id
and error_message is not null;
APEX_USED_DB_OBJ_DEPENDENCIES
This is the complete report showing for each component property, all the database objects it refers to.
select
page_id,
component_type_name, component_display_name,
property_group_name, property_name,
code_fragment,
referenced_type, referenced_owner,
referenced_name, referenced_sub_name
from apex_used_db_obj_dependencies
where application_id = :app_id;
(some columns were removed from this screenshot)
Using the API
The results of a scan will be retained until the application is re-scanned. You can scan any number of applications in your workspace and analyze the results all together if you need. If an application is modified, you can re-scan it to refresh the report.
You may find it useful, so I encourage you to give it a try. If you do, please note a few caveats:
The documentation for this API is not yet available, but is being worked on.
When APEX is upgraded to a new version, all report results are wiped. You can then re-scan your applications to get up-to-date results.
The reports do not include recursive dependencies – e.g. if your application refers to a view, the report will not list the underlying tables of the view.
If the application includes any plugins, the dependencies report will include references to some internal plugin-related APIs even if your code doesn’t directly reference them.
If your application executes any dynamic SQL or PL/SQL (e.g. using “execute immediate”), any dependencies arising from the dynamic code will not be reported.
There are some component properties that are not included in the scan, such as the column names in a report (however, the data source for the region is scanned).
In spite of the caveats, I’m sure there are quite a few ways this new API will prove useful. We expect it will be further improved in future releases, including being integrated into the APEX Application Builder.
Wherein I natter on about gear and how I choose what to buy. Perhaps with a point to make about software development.
Bilung Pool, Murchison
At least once a year we pack the Prado with a tent, gear and food and go camping with a group of friends. For a few days to a week or so we’d unplug, relax and enjoy God’s creation somewhere in our vast state of Western Australia.
I’m a frugal person so at first we only collected the bare essentials, got a tent on special for $100 big enough to fit the whole family. Every time we’d go camping we’d think about what worked well last time, and what could be improved, and perhaps get some extra gear or replace something to make things a bit easier. Got a 4WD vehicle so we could go to more places. Got a fast frame tent to reduce the time to set up (this makes a huge difference when we rock up to the site with 5 minutes of light left and three hungry kids). Bought a collapsible basin and bucket which allowed us to fit more gear in. Got some hardy camping boxes for gear. A waterproof rooftop bag for the car which fits all our clothing, pillows and sleeping bags. Ditched the self-inflating mattress that got all warped and took up heaps of space, for some cheap inflatable ones that would only last a year or so but pack down very tightly.
Improvements to the car have also been made. Instead of spending thousands of dollars getting a custom set up done, while not really knowing exactly how we want it set up, we have gradually added small upgrades a bit at a time. Auxiliary battery installed with an isolator so that our fridge and chargers would run without draining the starter battery. My friend installed some power points in the boot so I could run the fridge there, as well as some USB points for charging phones. This year he upgraded my setup to a DC/DC charger which has improved things a lot, and I got a folding solar panel so that I can keep things running (as long as there’s sunlight). Ran two fridges, one as a freezer and one as a fridge – and learned that my aux battery doesn’t have the capacity to keep them both running well, especially in high temperatures. So now I have an idea of what sort of fridge/freezer combo I’d like, and what sort of power usage efficiency I need to be looking for in such a unit.
Early on we were short on funds and we did everything “on the cheap”. This required being very selective about what things we bought, looking for bargains, and buying some things secondhand. Over time we got better at managing our finances, got our spending under control – and so were able to afford the occasional big upgrade when it seemed worthwhile. Instead of just buying cheap gear that frustrates us for a couple of years before they break, we can invest in higher quality products that last many years. Our spending is reasonable and intentional.
Cattle Pool, East Lyons River
Software development works well when done this way, as well. Sometimes it’s a good idea to quickly throw together a rough solution to get the job done. It only costs a small amount of time and gives us the opportunity to see if it really works, where are the rough edges, what areas need work, what features were never really needed in the first place. Later, we can throw part of it out and replace it with a more expensive component (expensive, as in taking a longer period of time and perhaps more manpower to build).
The “big bang” approach never really works in my opinion. It’s so tempting to want to divert down the “tear it all down and rebuild from scratch” road, especially when in the depths of trying to analyse and understand some complex behaviour arising from code that some developer (probably myself) wrote many months ago. You want to throw it all out and start again because that’s a lot more fun. Don’t believe it!
Any non-trivial project will have complexity that, whether you are on your own or are in a team, will have many issues that are difficult to resolve, many of which would have been resolved early on if a small prototype had been built first. This complexity is a simple consequence of the fact that every non-trivial system will be comprised of multiple smaller systems which need to work together; there are exponentially more ways for these mini-systems to interact and fail than you have consciously considered or tested.
Temple Gorge, Kennedy Ranges
I’m currently several years into a large project that is currently being used in production but still has a long list of features yet to be built. It originally started with a small prototype, that itself was an adaptation of a much older, smaller application. The prototype involved a few changes, improvements and refactorings but it was still recognizable from its progenitor. This prototype became a system that was used worldwide with great success, but not without some issues internally that made it difficult to extend and adapt.
These were architectural design issues that required a major redesign – but instead of building a whole new system “from scratch”, we designed the new system with the prototype as a basis. The new data model was an evolution of the original rather than being completely new. In some ways it might have been nicer to start with a completely new data model, but the approach we took meant that a lot of the code from the original simply needed to be adapted to the changes, and meant that we could get our beta version out for testing and evaluation quicker.
Several years later, we had gone back and rewritten, refactored, or even completely replaced large portions of the code; now, I suspect that there are very few, if any, lines of code that have survived from the original source. We’ve changed approaches, technologies and frameworks gradually, replacing one thing at a time. This has not always been smooth; sometimes edge cases and smaller features are forgotten or lost in a rewrite. On the whole, however, we have maintained continuity and releasing the product in small(ish) releases has been successful and generally been received positively.
Recently we went on a 4WD trip in my home state, Western Australia. The photos in this post were from that trip.
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;
/
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.“
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;
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
Alternatively, you can access the wizard via Edit Application Definition > Security > Session State Protection > Manage Session State Protection
The wizard starts by showing an overview of the current state of your application’s protection against URL tampering.
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.
I’ve selected the action Configure, then click Next.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.After reviewing the summaries of the changes that the wizard will make, I click Finish.
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.
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;
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:
Navigation – e.g. do the View or Edit buttons in all reports still work?
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.
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.
Here is my main page definition, with two regions. Each region has an item that we want to pass to/from our modal page.
Each region needs a unique Static ID.
Each region has a visible Value item, an Edit button, and a hidden item to precalculate the URL for the modal page.
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.
The other edit URL is similar.
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.
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“.
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.
The JavaScript Code redirects to the modal page using the URL we calculated on page load.
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.
The two “PART” items are calculated on page load with some PL/SQL:
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”:
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.
Back on the calling page, each region has a dynamic action defined on Dialog Closed.
The Set Value action copies the Dialog Return Item value into the appropriate item on the page.
Summary
To use my special modal page in my application, I need to:
Set a unique Static ID on the region
Add an Edit button with a dynamic action
Add a hidden URL item based on an expression
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 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 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.
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.
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.
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:
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.
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.
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.
