Tag: tips-&-tricks

Apex Reports: One Link, Multiple Destinations

Every Interactive Report has an optional set of “Link” attributes that allow you to specify the location where the user should be redirected if they click a link next to a record in the report. You can choose “Link to Custom Target” and use the Link Builder to easily specify the target application, page, item values to pass, and other attributes.

linkbuilder1

What if the report combines different entities, and you need to direct the user to a different page depending on the type of entity? Or, if you need to direct the user to a different page with different attributes depending on the status of the record?

One method is to generate the URL in the report query using apex_page.get_url (Apex 5+) or apex_util.prepare_url (Apex 4 or earlier), or (God forbid) you could generate the url yourself using string concatenation.

A more declarative solution is to instead use Apex page redirects. This solution involves the following:

  1. Add some hidden items to the page to store the parameters for each target page;
  2. Add a Branch to the page for each target page; and
  3. Add a Request to the link to signal the page that a redirect has been requested.

Here’s an example. My page 550 has an interactive report which combines TI records with TRQ records (both of which have a very similar structure). If the user clicks on a TI record they should be redirected to p510 with the corresponding TI_ID, and if they click on a TRQ record they should be redirected to p305 with the corresponding TRQ_ID.

Here’s the link attributes for this report:

linkbuilder2

Notice that the page now redirects back to itself with the request set to “GOTO_TARGET”, along with the IDs required. My report query has been constructed so that every record will only have a TI_ID or a TRQ_ID, never both at the same time; so the link will ensure that only one of the P550_GOTO_xxx_ID values will be set.

The page then just needs two Branches: one for each target. Conditions on each branch ensures they only get activated if the request has been set, and the branch is selected based on which “GOTO ID” item has been set:

branch1

branch2

For a normal navigation to this report (e.g. from another page), the request should be blank (or some other value) so none of the Branches should be triggered.

For a relatively simple scenario like this, I like the declarative approach. Each branch can take advantage of the full range of Apex features such as the link builder, security conditions, build options, etc.

Note: this method works just as well for Classic report links as well.

The thing to be mindful of is that the order of the branches, and the condition on each branch, must be carefully selected so that the correct branch is activated in each situation. I’ve shown a simple example which works because I have ensured that only one of the ID parameters is set at the same time. If a record has both IDs, the condition on the first branch “GOTO_TARGET (TI_ID)” will evaluate to True and it will be used, regardless of what GOTO_TRQ_ID was set to.

If there were numerous potential destination pages, with a large number of parameters to pass, I might choose the apex_page.get_url method instead.

Related

Show greyscale icon as red

I have an editable tabular form using Apex’s old greyscale edit link icons:

greyscale-icons

The users complained that they currently have to click each link to drill down to the detail records to find and fix any errors; they wanted the screen to indicate which detail records were already fine and which ones needed attention.

Since screen real-estate is limited here, I wanted to indicate the problems by showing a red edit link instead of the default greyscale one; since this application is using an old theme I didn’t feel like converting it to use Font Awesome (not yet, at least) and neither did I want to create a whole new image and upload it. Instead, I tried a CSS trick to convert the greyscale image to a red shade.

I used this informative post to work out what I needed: https://css-tricks.com/color-filters-can-turn-your-gray-skies-blue/

WARNING: Unfortunately this trick does NOT work in IE (tested in IE11). Blast.

Firstly, I added a column to the underlying query that determines if the error needs to be indicated or not:

select ...,
       case when {error condition}
       then 'btnerr' end as year1_err
from mytable...

I set the new column type to Hidden Column.

The link column is rendered using a Link-type column, with Link Text set to:

<img src="#IMAGE_PREFIX#e2.gif" alt="">

I changed this to:

<img src="#IMAGE_PREFIX#e2.gif" alt="" class="#YEAR1_ERR#">

What this does is if there is an error for a particular record, the class "btnerr" is added to the img tag. Rows with no error will simply have class="" which does nothing.

Now, to make the greyscale image show up as red, I need to add an SVG filter to the HTML Header in the page:

<svg style="display:none"><defs>
  <filter id="redshader">
    <feColorMatrix type="matrix"
      values="0.7 0.7 0.7 0 0
              0.2 0.2 0.2 0 0
              0.2 0.2 0.2 0 0
              0   0   0   1 0"/>
  </filter>
</defs></svg>

I made up the values for the R G B lines with some trial and error. The filter is applied to the buttons with the btnerr class with this CSS in the Inline CSS property of the page:

img.btnerr {filter:url(#redshader);}

The result is quite effective:

greyscale-colorize

But, as I noted earlier, this solution does not work in IE, so that’s a big fail.

NOTE: if this application was using the Universal Theme I would simply apply a simple font color style to the icon since it would be using a font instead of an image icon.

Quick Pick in Apex Report

I have an Interactive Report that includes some editable columns, and the users wanted to include some “quick picks” on these columns to make it easy to copy data from a previous period. The user can choose to type in a new value, or click the “quick pick” to quickly data-enter the suggested value.

example-report-quickpick

Normally, a simple page item can have a quick pick by setting the Show Quick Picks attribute on the item. This is not, however, available as an option when generating Apex items in a report.

To do this, I added code like the following to my report query: NOTE: don’t copy this, refer to ADDENDUM below

SELECT ...
      ,APEX_ITEM.textarea(5,x.ytd_comments
         ,p_rows => 1
         ,p_cols => 30
         ,p_item_id => 'f05_'||to_char(rownum,'fm00000'))
       || case when x.prev_ytd_comments is not null
          then '<a href="javascript:$(''#'
            || 'f05_' || to_char(rownum,'fm00000')
            || ''').val('
            || apex_escape.js_literal(x.prev_ytd_comments)
            || ').trigger(''change'')">'
            || apex_escape.html(x.prev_ytd_comments)
            || '</a>'
          end
       as edit_ytd_comments
FROM my_report_view x;

This results in the following HTML code being generated:

html-report-quickpick

In the report definition, the EDIT_YTD_COMMENTS column has Escape Special Characters set to No. This runs a real risk of adding a XSS attack vector to your application, so be very careful to escape any user-entered data (such as prev_ytd_comments in the example above) before allowing it to be included. In this case, the user-entered data is rendered as the link text (so is escaped using APEX_ESCAPE.html) and also within some javascript (so is escaped using APEX_ESCAPE.js_literal).

So, if the data includes any characters that conflict with html or javascript, it is neatly escaped:

html-quickpick-bad

And it is shown on screen as expected, and clicking the link copies the data correctly into the item:

example-quickpick-bad

This technique should, of course, work with most of the different item types you can generate with APEX_ITEM.

Recommended further reading:

ADDENDUM 6/2/2017

A problem with the above code causes this to fail in Internet Explorer (IE11, at least) – when clicking on the quickpick, the user is presented with a page blank except for “[object Object]”. After googling I found this question on StackOverflow and fixed the problem by moving the jQuery code to a function defined at the page level.

I added this to the page Function and Global Variable Declaration:

function qp (id,v) {
  $(id).val(v).trigger('change');
}

And modified the report query as follows:

SELECT ...
      ,APEX_ITEM.textarea(5,x.ytd_comments
         ,p_rows => 1
         ,p_cols => 30
         ,p_item_id => 'f05_'||to_char(rownum,'fm00000'))
       || case when x.prev_ytd_comments is not null
          then '<a href="javascript:qp(''#'
            || 'f05_' || to_char(rownum,'fm00000')
            || ''','
            || apex_escape.js_literal(x.prev_ytd_comments)
            || ')">'
            || apex_escape.html(x.prev_ytd_comments)
            || '</a>'
          end
       as edit_ytd_comments
FROM my_report_view x;

Target=_Blank for Cards report template

cardsreport.PNGI wanted to use the “Cards” report template for a small report which lists file attachments. When the user clicks on one of the cards, the file should download and open in a new tab/window. Unfortunately, the Cards report template does not include a placeholder for extra attributes for the anchor tag, so it won’t let me add “target=_blank” like I would normally.

One solution is to edit the Cards template to add the extra placeholder; however, this means breaking the subscription from the universal theme.

As a workaround for this I’ve added a small bit of javascript to add the attribute after page load, and whenever the region is refreshed.

  • Set report static ID, e.g. “mycardsreport”
  • Add Dynamic Action:
    • Event = After Refresh
    • Selection Type = Region
    • Region = (the region)
  • Add True Action: Execute JavaScript Code
    • Code = $("#mycardsreport a.t-Card-wrap").attr("target","_blank"); (replace the report static ID in the selector)
    • Fire On Page Load = Yes

Note: this code affects all cards in the chosen report.

Report Link: Save before Navigation

“We always click ‘Apply Changes’, then we click the button we actually wanted” – a user

Typically an Apex report with an “Open” or “Edit” icon will simply do an immediate navigation to the target page, passing the ID of the record to edit. When the user clicks this link, the page is not submitted and the user is instead redirected.

It’s easy to quickly build large and complex applications in Apex but it’s also very easy to build something that confuses and disorients your users. They only need one instance when something doesn’t work how they expected it to, and they will lose trust in your application.

For example: if most buttons save their changes, but one button doesn’t, they might not notice straight away, and then wonder what happened to their work. If you’re lucky, they will raise a defect notice and you can fix it. More likely (and worse), they’ll decide it’s their fault, and begrudgingly accept slow and unnecessary extra steps as part of the process.

You can improve this situation by taking care to ensure that everything works the way your users expect. For most buttons in an Apex page, this is easy and straightforward: just make sure the buttons submit the page. The only buttons that should do a redirect are those that a user should expect will NOT save the changes – e.g. a “Cancel” button.

For the example of an icon in a report region, it’s not so straightforward. The page might include some editable items (e.g. a page for editing a “header” record) – and if the user doesn’t Save their changes before clicking the report link their changes will be lost on navigation.

To solve this problem you can make the edit links first submit the page before navigating. The way I do this is as follows (in this example, the report query is on the “emp” table:

    1. Add a hidden item P1_EDIT_ID to the page
      • Set Value Protected to No
    2. Add something like this to the report query (without the newlines):
      'javascript:apex.submit(
        {request:''SAVE_EDIT_ROW'',
         set:{''P1_EDIT_ID'':''' || emp.rec_id || '''}
        })' AS edit_link
      • Set this new column to Hidden Column
    3. Modify the edit link Target:
      • Type = URL
      • URL = #EDIT_LINK#
    4. Add a Branch at point “After Processing”
      • Set the Target to the page to navigate to
      • Set the item for the record ID to &P1_EDIT_ID.
      • Set the Condition to the following PL/SQL Expression:
        :REQUEST='SAVE_EDIT_ROW' AND :P1_EDIT_ID IS NOT NULL
      • Make sure the branch is evaluated before any other branches (at least, any others that might respond to this request)
    5. Modify any existing Processing so that the request SAVE_EDIT_ROW will cause any changes on the page to be saved.

You can, of course, choose different item names and request names if needed (just update it in the code you entered earlier). For example, to make it work with the default Apex DML process you might need to use a request like “APPLY_CHANGES_EDIT_ROW”.

Now, when the user makes some changes to the form, then clicks one of the record Edit links, the page will first be submitted before navigating to the child row.

Adding buttons to Apex pages is easy. Making sure every last one of them does exactly what the user expects, nothing more, and nothing less, is the tricky part!