All posts by Rob Wunderlich

QSDA Pro 2.5 Brings Extended Expression Validation

Summary: Set Modifier field names and Set Identifiers are not validated by Qlik syntax check. QSDA Pro 2.5 validates everything and raises an “Unrecognized Name” flag for invalid names.

QSDA Pro syntax checks all expressions in a Qlik App using the Qlik syntax checker. You’re familiar with the Qlik syntax checker. It’s the message at the bottom of the expression editor that tells you your expression is “OK”.

The syntax checker is also good at telling you when the expression has an error, although it’s not always specific about the problem.

QSDA Pro, using the Qlik API version of syntax checker, tells you what is wrong with the expression:

The Qlik syntax checker has a significant limitation. It does not validate field names used in sets. Whether used in the API or the editor, the syntax checker will not raise an error if the field “EmpPurchase” does not exist in the data model.

This lack of validation can be a serious problem if “EmpPurchase” is removed or renamed in the data model. The expression will still return a number but the exclusion of employee purchases will no longer be applied. That could be a very subtle but important fail.

Recognizing this limitation and it’s potential impact, QSDA Pro 2.5 validates all names used in sets and will raise a new Quality flag, “Unrecognized Name”, if the name is invalid.

Another place this validation is extremely useful is Chart Filters in Qlik SaaS. The chart will cheerily display that filter “Expression2 > 1” is being applied. Even though field “Expression2” no longer exists in the data model.

But QSDA knows.

Ever use a bookmark as a set identifier? And then the bookmark got deleted or renamed?

I’ve used simple examples to demonstrate, but where this validation really shines is in longer expressions where it may be easier to overlook that something has gone wrong.

Yes, you need QSDA Pro. We all need QSDA Pro.

Learn more about QSDA Pro and download your own copy at https://easyqlik.com/qsda/

-Rob

What does QSDA stand for? Qlik Sense Document Analyzer. The combination of data model and sheets we know as an “App” in Qlik Sense was called a “Document” in QlikView. When I first created this tool in 2009 to help maintain QlikView, I called it “Document Analyzer”. When it came time to create a similar tool for Qlik Sense, I stuck with the “DA” name as the function and usefulness of “Document Analyzer” was well established in the Qlik community.

Share

Motio Acquires QSDA Pro

I’m pleased to announce that I’ve joined forces with Motio, Inc, producers of the great DevOps tools Soterre and Gitoqlok. Motio has acquired my QSDA Pro product and I’m excited to combine our tools to provide a comprehensive platform for professional Qlik App development in Qlik Sense and Qlik SaaS. You can read the announcement here.

I will continue to lead the development of QSDA Pro, enhancing the product and bringing new superpowers to my customers in the integration with Soterre and Gitoqlok.

The QSDA Pro customer base is growing fast! To date hundreds of organizations have purchased QSDA Pro and are realizing the full benefits of the tool. More are joining every day and I’m excited to add Motio’s dedicated product support and admin teams to handle this growth.

You can continue to learn more and purchase QSDA Pro online .

Share

Gitoqlok for Qlik Sense Version Control

Gitoqlok is a free chrome plugin that allows you to use a git repository such as GitHub, GitLab, Azure DevOps, etc, to manage all the pieces of Qlik Sense app — Measures, Sheets, Charts, Load script and more.

The plugin operates seamlessly within the Qlik Sense authoring experience to provide the power of fine grained version control you expect with git. You’ll see a list of changes and commit those changes as you would expect in any software development project. Of course there is collision detection, branching and merging and all the goodness you expect from git.

Because the Gitoqlok team understands the visual nature of Qlik development, you can view diffs in a visual format. A slider lets you pick a commit for compare.

You can also use the same slider in a non-diff “time machine” mode to see how the application sheets looked at any point in time.

Gitoqlok comes with a lot of very useful Qlik dev features, such as the ability to import a chart or script snippet from app to another. Or deploy an entire app from one server to another!

Most Gitoqlok features are free to use. Premium features and support are available in a reasonably priced subscription.

If you haven’t tried Gitoqlok I recommend you give it a spin. You can install the plugin from the Chrome Store. Learn more about Gitoqlok including some great intro videos.

If you are attending QlikWorld next week Drop by the Motio booth (#315) to see more. Motio is also presenting two breakout sessions showcasing Gitoqlok, including their integration with my QSDA Pro tool.

-Rob

Share

Qlik App Performance Tuning — March 29

My Masters Summit for Qlik colleague Oleg Troyansky will be presenting his always valuable “Performance Tuning” course on March 29 as part of our “Masters Summit at Home” online series.

Oleg will do a deep dive into the causes and corrections for Qlik App performance issues. He’ll explain the why of good and bad performance while explaining important Qlik Engine concepts and demonstrating best practices. I highly recommend this course.

Oleg will demonstrate available performance tools including my favorite — QSDA Pro. As part of the class each student will receive a trial license key for QSDA and I’ll be available before and after class to help you get QSDA installed and configured.

Also coming up in the “Masters Summit at Home” series:

Effective Visualizations” with Bill Lay on March 15. Bill will teach you how to effectively “tell the story” using Qlik visualizations in a series of interesting and challenging scenarios. Bill is an engaging and thoughtful presenter. I always come away from Bill’s lectures with fresh ideas and useful tools.

Are you Qlik Integration / API curious? Want to understand the potential of combining the web and the Qlik platform? Join Nick Webster on April 12 for “Qlik Sense Integration“. Nick begins by showcasing Qlik embedded in intriguing and useful ways. He then moves on to teach the basics of web technologies HTML, CSS and Javascript, which you will then use to construct a fully functional, interactive Qlik web application in class. No web programming experience necessary!

Share

Mind the Concat() sort-weight

Summary: While looking into long expressions I noticed that the optional sort-weight argument has an impact on the distinctness of Concat(distinct…). Incorrect use of sort-weight can generate bloated expressions containing redundant code.

In my work tuning Qlik Apps I sometimes encounter very long expressions. An expression many thousands of characters long can be difficult to debug or comprehend the expression goal. To help in working with long expressions I’ve added an Expression histogram and an Expression Decoder feature to my QSDA Pro product. (These features are currently in beta, generally available in early Feb).

I’ve noted expressions of length greater than 50k across apps from different customers. What did these expressions have in common that made them so large?

  • They used the Concat() function in $() to dynamically generate a part of the expression.
  • They used the optional sort-weight argument of Concat() incorrectly.
  • They were much bigger than necessary — sometimes 100x — but the expanded expression worked as intended.

In the process of reviewing the expressions I learned something surprising. As a reminder here’s the syntax of the Concat function:

Concat({[SetExpression] [DISTINCT] [TOTAL []]} string[, delimiter[, sort_weight]])

We use the DISTINCT keyword to return the unique set of values from the string argument (usually a field). The Qlik documentation for DISTINCT says:

If the word DISTINCT occurs before the function arguments, duplicates resulting from the evaluation of the function arguments are disregarded.

https://help.qlik.com/en-US/sense/November2022/Subsystems/Hub/Content/Sense_Hub/ChartFunctions/StringAggregationFunctions/concat.htm

This means that the set of distinct values is the combinations of string and sort_weight (if used). Let me demonstrate with an example. Here’s a sample data table.

For the expression: Concat(Dim, ',') we receive output "a,b,c,c,c“.

Adding the DISTINCT keyword: Concat(DISTINCT Dim, ',') we now get “a,b,c“.

Adding a non-distinct sort-weight argument: Concat(DISTINCT Dim, ',', RecId) we now get "a,b,c,c,c” again. More output than I expected. It’s a distinct list of the combinations of Dim and RecId.

Adding a distinct sort-weight argument: Concat(DISTINCT Dim, ',', Weight) we now get "a,b,c“.

How about if we used an unlinked data island field for sort-weight? The Island field has two values.

Concat(DISTINCT Dim, ',', IslandField) returns "a,b,c,a,b,c“. Item count is the product of Dim * IslandField values. Remember this for later.

Ok, this is all very interesting but the behavior is super obvious and I would notice it if it came up in my App. What’s this got to do with ginormous expressions?

Developers sometimes use Concat along with Dollar Sign Expansion (DSE) to generate dynamic expression fragments. For example to ignore all fields from several tables in a set modifier:

Sum ({<
$(='[' & concat({<$Table={'Table1', 'Table2', 'Table3'}>}$Field,']=,[') & ']=')
>} Value)

Sometimes $(=Concat(...)) is used to build the list inside a Pick() or Match(). These type of expressions frequently have awkward syntax including lots of “& chr(39) &” type stuff. Inevitably the expression gets built by copying and modifying an expression from elsewhere in the App. An expression that contains a sort-weight. A sort-weight that doesn’t get removed. It may be an island field or a field that has a many to one relationship. The result is an expanded expression that works but is larger than it needs to be. No one notices (unless they use QSDA Pro) because it’s the expanded expression.

As a simple example, suppose the “ignore filter” expression above was supposed to generate something like "Quarter=,Month=,Year=“. If I inadvertently use a sort-weight field that has 100 distinct values the result will be repeated 100 times. The expression would still work but it would be 100x larger than necessary.

I recently found an example where Concat was used to generate an If() function from data (very clever) that should have had 15 branches. But an unrelated sort-weight field of 95 values resulted in 1425 branches! It “worked” but did a lot of unnecessary calculation.

If you are a solo developer or working in a small team you may never encounter this issue. But if you are a consultant or maintaining legacy Apps you may stumble across it. I’ve been playing with ways to flag this condition in QSDA Pro. QSDA already flags data island expressions . I’m testing creating a new flag specifically for Concat().

My colleague Oleg Troyansky uses QSDA in his Performance Tuning session at the Masters Summit for Qlik. Live events will return in Fall 2023 but in meantime you can attend individual workshops on-line during February through April. More information and schedule here.

Happy Qliking
-Rob

Share

Outer Sets Bring New Reusability

Summary: I demonstrate how outer sets in Qlik expressions can be used to extend the reusability of Master Measures.

The new outer sets feature in Qlik brings new opportunities for Master Measure reuse in Qlik Sense and QlikView. See this post by Henric Cronström for an explanation of the new feature.

Without outer sets if we wanted to inject set analysis into a measure, we had to copy the expression text and edit. Consequently we are no longer linked to the master item and have lost the maintenance and quality benefits of being linked.

Let’s look at an example where outer sets can improve reusability. In our sample scenario, the business rule for “Sales” is sales receipts minus returns and excluding employee purchases. Our Sales master measure might look like this:

Note that we had to repeat the same set inside each aggregation. We can simplify the expression by using outer set syntax and defining the set once.

This does nothing for reusability, but I believe it improves maintainability. The outer parentheses are not strictly necessary in this case, but they do make it clearer that the set applies to the entire expression.

Continuing on we define a COGS measure:

Note that we could have used the outer set syntax, but I don’t see any advantage to that here.

With the ability to use Measure names in expressions, available in Feb 21 release, let’s define a Margin measure.

Now we can drag the Sales and Margin measure into a KPI.

Now we want to do Sales and Margin for the current year only. Our data requires that we inject a new set. This is where outer sets really shine. The Current Year Sales measure using an outer set:

The Current Year Margin measure:

Note that we have maintained our linkage to the Sales and Margin master measures!

In review, here are all five Measures taking advantage of the outer sets syntax.

I’m happy to see outer sets available in the product. I look forward to the day when sets may be master items!

-Rob

Share

The New Qlik Simplified Authoring Mode

Qlik has implemented a new “Simplified Authoring” experience in the SaaS (Cloud) environment. It’s available as an optional preview now and will be implemented for all SaaS tenants in mid-August.

I won’t describe the new features as they are well described here. If you haven’t already, I recommend you read the post and then come back here for my comments.

I think this is really great work and a significant improvement to the chart authoring experience. It not only makes it easier for newbies to create charts, I prefer using this interface in most cases. What do I like about it?

Moving the data panel to the left and increasing the display density is much more productive and fluid. This change seems to signal the death of the “iPad first” design. I’m pretty happy about that. The ability to work with field values while in design mode is fantastic.

The addition of the Data Table is brilliant. It’s much more fluid than swapping tabs to use the Data Model Viewer or building a temp table on the canvas.

I didn’t think I would like the “smart grid” feature but I’ve become a fan. With additional elements like Data Table the working canvas becomes relatively smaller and I’ve found it simplest to just add my chart in the general location and move on. As a final step I can switch to advanced mode and fine tune the chart locations and sizes if necessary.

Very cool feature to me is the new Chart Filters. This filter is implemented as a set expression applied to the data before expression set analysis is applied. So you now have three layers of data filtering — User Selections, Chart Filter, Expression (Measure) set analysis.

The chart filter is requested by a set expression in hypercube property qHyperCubeDef.qContextSetExpression . So you can use it in the Engine API if the engine level supports it. Potentially we could see Chart Filters available in a future QSEoW release. I think it would be useful to have Chart Filters as a master item for reusability and consistency.

If you are using QSDA Pro to evaluate your Qlik Sense apps (why not!), QSDA Pro release 2.1 supports capturing and parsing the new Chart Filters.

Want to up your Qlik Development game? Register for the Masters Summit for Qlik — Madrid 19 Sept or New Orleans 14 Nov — three days of advanced Qlik Developer training and tips.

-Rob

Share

Roll Your Own Qlik “Connector”

Summary: I demonstrate how to use a simple Python REST server to wrap any data source for loading by the Qlik REST connector.

In my years of Qlik development I have many times needed to load data from a source not supported by available connectors. Sometimes the data resides on a factory floor controller and can only be accessed using something like telnet. One approach is to create a batch process that extracts the data to a flat file accessible to Qlik. This works, but you have to deal with issues of timing and failure monitoring.

If you want real time direct loading from Qlik script, you can write a custom connector for your data source. Writing a custom connector is a programming chore of medium complexity and there are limited languages you can work in.

As an alternative to a custom connector or batch process, I’m going to show how you can use the out-of-the-box Qlik REST connector to access your special data, wherever it lives!

REST is a popular way of exchanging data between systems. Data is requested from a REST Endpoint using a URL like:

http://localhost:3000/customers

Data is returned in JSON format like:

[{"Name": "Abc corp", "City": "New York"},
{"Name": "GeoFarm": "City": "Boston"}]

The Qlik REST connector translates JSON data into the rows and fields of a Qlik table. This URL request + JSON output makes it very easy to test REST endpoints using a browser.

Due to REST’s popularity, the tools we need to create REST endpoints are available in just about all programming languages, platforms and lowcode services. Use whatever language you are familiar with or that runs in your environment. I’m going to show a quick example using Python. If you want to create this example yourself, make sure you have Python 3+ installed along with the packages Flask and Pandas.

For my “special data source”, I’m going to use output from the Windows “Tasklist” command. The output looks like below.

Our REST Endpoint must provide three components:

  1. A web server that will handle the incoming URL.
  2. Data from our special/custom data source.
  3. A conversion of data from our native format to JSON.

Here is a complete Python program that satisfies all three requirements.

from flask import Flask, json
from io import StringIO
import pandas as pd
api = Flask(__name__)

@api.route('/tasklist', methods=['GET'])
def get_tasklist():
    import subprocess
    subprocess = subprocess.Popen("tasklist /FO CSV", shell=True, stdout=subprocess.PIPE, text=True)
    csvStringIO = StringIO(subprocess.stdout.read())
    df = pd.read_csv(csvStringIO);
    return Response(df.to_json(orient='records'), content_type='application/json')
if __name__ == '__main__':
    api.run(port=3000, host='0.0.0.0') 

Save this code in file “SimpleRest.py” and start the python task with the command:

python SimpleRest.py

In a Qlik App, create a new REST connection. The URL will be our new REST endpoint. If your Python task is running on other than “localhost”, change the host in the URL.

Give it a Name. Test and Save.

Use the “Select data” button on the connection and select the “root” table. The Qlik wizard will build the required script.

Reload and you should have data!

Let’s break down the pieces of the python program to understand what you would change and what you would re-use in a new scenario.

The first four lines import required libraries and initialize Flask, the REST library we will use. Here is the remaining code.

@api.route('/tasklist', methods=['GET'])
def get_tasklist():
    import subprocess
    subprocess = subprocess.Popen("tasklist /FO CSV", shell=True, stdout=subprocess.PIPE, text=True)
    csvStringIO = StringIO(subprocess.stdout.read())
    df = pd.read_csv(csvStringIO);
    return Response(df.to_json(orient='records'), content_type='application/json')
if __name__ == '__main__':
    api.run(port=3000, host='0.0.0.0') 

The bolded lines above start a webserver listening on port 3000 and declare what code will run when the URL path is “/tasklist”.

@api.route('/tasklist', methods=['GET'])
def get_tasklist():
    import subprocess
    subprocess = subprocess.Popen("tasklist /FO CSV", shell=True, stdout=subprocess.PIPE, text=True)
    csvStringIO = StringIO(subprocess.stdout.read())
    df = pd.read_csv(csvStringIO);
    return Response(df.to_json(orient='records'), content_type='application/json')
if __name__ == '__main__':
    api.run(port=3000, host='0.0.0.0') 

These two lines above run the tasklist /FO CSV command and capture the output. To make wrangling easier I added tasklist options “/FO CSV” which generates output in CSV format.

@api.route('/tasklist', methods=['GET'])
def get_tasklist():
    import subprocess
    subprocess = subprocess.Popen("tasklist /FO CSV", shell=True, stdout=subprocess.PIPE, text=True)
    csvStringIO = StringIO(subprocess.stdout.read())
    df = pd.read_csv(csvStringIO);
    return Response(df.to_json(orient='records'), content_type='application/json')
if __name__ == '__main__':
    api.run(port=3000, host='0.0.0.0') 

Lastly we wrangle the output from CSV to JSON format and send the data to the requestor.

I hope you can see from this example how easy it can be to expose your custom data to Qlik and have real time loading. I used Python for this example, but you could implement this same example in many languages with little effort.

if you’ve created my example in your own environment, you should now be able to create a treemap chart of Memory Usage. Tip: parse the [Mem Usage] field in the script with

Num#(SubField([Mem Usage], ' ', 1), '#,##0') * 1024 as [Mem Usage]

Want to talk more data loading techniques? Join me at the Masters Summit for Qlik in Fall 2022 where in addition to heads down learning, we’ll be kicking the tires on things like Server Side Extensions and Qlik Application Automation.

-Rob

Share

Masters Summits 2022

We’re baaaack!  After a two year break from live events, I’m pleased to announce that the Masters Summit for Qlik starts up again in Fall 2022. 

Masters Summit 2022 Madrid and New Orleans

Madrid – September 19-21

New Orleans – November 14-16

Our goal in this three day hands on education event is to “Take your Qlik skills to the next level”  to make you more productive and increase the business value of your Qlik Sense or QlikView applications.

Through lecture,  hands on activities and takeaway code samples,  the Summit will expand your knowledge with advanced techniques and a deeper understanding of the core skills required in all Qlik application development:

  • Data Modeling
  • Advanced Scripting
  • Advanced Aggregation & Set Analysis
  • Visualization.

In addition to core topics, we’ll have 1/2 day workshops on performance tuning and an introduction to creating Qlik Sense mashups using APIs.  See the complete agenda here.

Our evening guest speakers, networking events and optional lunchtime lectures fill out the program with additional content and lively discussion.

Our panel of five presenters are well known as authors, educators,  Qlik experts and members of the Qlik Luminary and MVP programs.

Have you taken basic Qlik training and/or worked with the product for a while?  Do you find yourself struggling with data modeling questions such as slowly changing dimensions and rolling time analysis?  Syntax for aggregation questions like “what products do top salesreps in each region sell?”  When do I need “$()” and when do I not?  

I hope you can join us in Madrid or New Orleans to take your Qlik skills to the next level.  The early bird registration discount is available until August 19.  Event details and online registration.

See you there!

-Rob

Share

QSDA Pro 1.7 is Released, What’s New?

QSDA Pro 1.7 is Released. So What’s New?

The QLIKLOGIN connection method allows your QSDA users to connect to Qlik Sense using the same login process they use for the Hub — Windows, SAML, whatever. After logging in, user “Sally” will see only her apps — the same list Sally would see in the Qlik Sense Hub.

The “Filter using this flag” button filters all your resources to everything associated with this flag, giving you fast focus on what needs to be examined or remediated.

Hyperlinks in resource lists provide one click to open the subject Viz in the Qlik Sense sheet editor.

Still my favorite QSDA feature, Viz Deconstruction itemizes the calculation time of each individual expression in a chart so you can focus in on what the heck is taking so long in this chart.

Stuff Administrators Will Love

  • Password protect Admin pages
  • Offline license keys for air gapped servers
  • Possible to install QSDA without Windows Admin rights
  • Https support
  • Optional API security

What Can QSDA Pro Do For Your Team?

  • Expose undetected errors — before your users do!
  • Gives actionable advice
  • insight and focus for developing and debugging
  • Save time on tasks like “how/where are we using field ‘abc’?”

Join a Webinar

“Introducing QSDA Pro” will show you the features and benefits offered in QSDA Pro, as well as an opportunity to ask questions.

Share