I figured this would be something that would be fairly-well documented as its a central theme to JasperReports, however I can't find an answer for this anywhere.
What is the purpose/function/intention of a details band? Is it supposed to just be the central or core part of a report?
From another question it was pointed out to me that there is a 1:1 relationship between a details band and a record/bean provided by the JRDatasource. This revelation brings to light a few tangential questions:
It is possible to add detail bands programmatically in Java; what happens if you specify more/less detail bands (programmatically) than there are records/beans returned by your JRDataSource?
What is the relationship between a details band, and say, a page inside an exported PDF document? Does 1 details bands translate to 1 page?
What happens if you pass the JasperFillManager a null data source? Is it possible to still have detail bands?
I don't like to ask multiple questions at a time, but these are so similarly-related I'd rather do it all at once than clutter SO with multiple nearly-identical questions. Thanks in advance.
The details band is indeed the band where each element of the data source is reported. The report engine automatically iterates over the data source and inserts data into the template of the detail band with respective element of the data source.
You may of course have several elements on a single page. According to the properties of the band (split allowed, height, etc.), the paging will be handled by Jasper Reports automatically, and it's the engine that will thus decide how many elements are printed on each page, when to go to the following page, etc.
The details band is not printed if you have nothing in the data source. The printing of the other bands depend on the parameters of the report.
The purpose of the detail band is to provide you with a model where you place and configure report elements. I don't think the relationship between a bean and detail band is one to one, since you can place many bean property elements in one bean. So, i would say the detail band is tightly tied to a collection of report bean elements.
One difference though, is the fact that detail band's functionality is irrelevant to how many beans/records you provide through a JRDataSource. The detail band will iterate through all of them until the data source is "consumed".
Furthermore, i personally find it very useful that the detail band allow you to iterate through a collection of bean properties. So, placing several properties in a detail band will iterate through all of them, before proceeding forward.
If you pass a null as DataSource you wont get any data on the report, and only static text will show up.
As I remember it, you can see the details band as the "model" for a row/record in the report. All elements you put inside the detail band will be repeated for each record provided by the JRDatasource.
For example, your details band might have two text fields, one with the value ${companyName}, and one with the value value ${revenue}.
If you now pass your report three rows, then "companyName" and "revenue" will be evaluated for each of them, and you may get something like:
|Apple | $1000,000,000|
|Microsoft | $500,000,000|
|My amazing company | $12|
I.e., the detail band contents has been repeated three times.
So:
- As you see you probably only need one details band configured. Not sure if it's allowed in the JRXML to have multiple ones.
- There is no relationship between the details band and a page. Pagination is handled separately.
- Not sure, to be honest. My best guess is either an exception or you get no rows where the detail band is supposed to be rendered.
You misunderstand what a detail band is.
The detail band of your report will be printed for each of the elements in your datasource. If you use a database datasource, the detail will be printed as many times as rows has your resultset. If you use a JRBeanCollection datasource, the detail band will be printed as many times as items has your collection.
To answer your questions:
You can't specify more than one detailband, it's illegal. You can
use subreports for that purpose.
The report will output as many detail bands as it can per page. On the otherhand, you can make the detail band the same height your desired report
output will be (minus header/footer/etc height). If you want to print the report in an A4 paper you
can make your detail band 297 mm high (considering you have no other bands). Then each detail band will be
printed in a separate page.
If you pass an empty datasource, the report will be generated with
no pages.
The information you have is correct, you've just had a slight misunderstanding of what it means.
The 1:1 relationship is at fill-time; Once the report has been filled there will be exactly 1 detail band for every record in the dataset. When you are designing the report you only add the band once, but that one band is repeated over and over again when the report is filled.
You can add as many detail bands as you wish. Each of the bands have a 1:1 relationship with the dataset records, and all of the detail bands are filled before moving on to the next record (i.e. If you have three bands A, B, and C; Their order in the report will be ABCABC... not AAA...BBB...CCC...).
It is possible to add bands programmatically, but the important point to note is that you are adding bands to the report design, not to the completed report. So just as with a jrxml design, you add the band once and it gets repeated for each record. Check this example.
There isn't a relationship between report pages and detail bands. The report filler will try to put as much onto a page as possible while respecting the splitType of each band as well as other report properties.
Is passing a null datasource is allowed? In any case the 1:1 relationship is still valid: A dataset with 0 records produces 0 detail bands in the report.
Related
I'm defining a lot of counters in my app (using java micrometer) and in order to trigger alerts I tag the counters which I want to monitor with "error":"alert" so a query like {error="alert"} will generate multiple range vectors:
error_counter_component1{error="alert", label2="random"}
error_counter_component2{error="alert", label2="random2"}
error_counter_component3{error="none", label2="random3"}
I don't control the name of the counters I can only add the label to the counters I want to use in my alert. The alert that I want to have is if all the counters labeled with error="alert" increase more then 3 in one hour so I could use this kind of query: increase({error="alert"}[1h]) > 3 but I get the fallowing error in Prometheus: Error executing query: vector cannot contain metrics with the same labelset
Is there a way to merge two range vectors or should I include some kind of tag in the name of the counter? Or should I have a single counter for errors and the tags should specify the source something like this:
errors_counter{source="component1", use_in_alert="yes"}
errors_counter{source="component2", use_in_alerts="yes"}
errors_counter{source="component3", use_in_alerts="no"}
The version with source="componentX" label is much more fitting to prometheus data model. This is assuming the error_counter metric is really one metric and other than source label value it will have same labels etc. (for example it is emitted by the same library or framework).
Adding stuff like use_in_alerts label is not a great solution. Such label does not identify time series.
I'd say put a list of components to alert on somewhere where your alerting queries are constructed and dynamically create separate alerting rules (without adding such label to raw data).
Other solution is to have a separate pseudo metric that will obnly be used to provide metadata about components, like:
component_alert_on{source="component2"} 1
and. combine it in alerting rule to only alert on components you need. It can be generated in any possible way, but one possibility is to have it added in static recording rule. This has the con of complicating alerting query somehow.
But of course use_in_alerts label will also probably work (at least while you are only alerting on this metric).
I was reading through a few active SO questions and I came across this one that reminded me of a question that I have had for a while.
In a few applications that I have done, there came a point when I had to use a view that uses category totals to display some easy to read values, such as cost, or counts, or whatever. Up until now, I have always had to find workarounds for these totals because I could not get them to show up in the dynamicViewPanels, or anything else of the like. My solutions have always been, (as David Leedy suggests in the linked question) static HTML tables displaying the counts with the category, View Navigators which display the information in repeaters, and building complex dialogs which allow the user to pick certain information to get a calculation table with the appropriate values and formulas etc.
My question is, did I overlook something in the controls that actually allow these column totals to show up in the existing view panel controls?
EDIT
Just for the sake of clarity, I am not talking about a column with a calculated value, but really the totals for categories.
There is a ready baked function that uses a ViewNavigator to get to values from category totals. That just might do the trick for you.
I'm relatively new to Java programming and currently using IBM's Rational Functional Tester tool (version 8.5). Before I start, my programming terminology isn't the best, so apologies if I use the wrong terminology in various places. I have also looked around on the IBM website, this site and various other websites but haven't been able to find a solution for this problem :(
I'm currently trying to create an automated test flow (for a web application) but I'm struggling with 1 particular section.
Here's the scenario: On page 1, I have a set of simple yes/no radio buttons. On page 2, I have a group of listboxes (1 set of listboxes in 1 column, and another set of listboxes in another and both sets contain different information). The amount of listboxes seen on page 2 will depend on the amount of yes/no answers given on page 1. If a user says "yes" to every single question, then there will be a hell of a lot of listboxes to data drive (close to 100).
Currently, I'm using this code to populate these listboxes:
TestObject[] listboxes
listboxes = html_application().find(atDescendant(".class", "Html.SELECT"), false);
for(int i = 0 < i < listboxes.length; i++)
{
GuiTestObject button = (GuiTestObject)listboxes[i];
RootTestObject boxes = getRootTestObject();
TestObject[] list = boxes.find(atDescendant(".class", "Html.SELECT"));
SelectItemGuiTestObject gto = (SelectGuiSubItemTestObject) list_viewFormList2View();
gto.select(dpString("Identity_Type"));
RootTestObject boxes2 = getRootTestObject();
TestObject[] list2 = boxes2.find(atDescendant(".class", "Html.SELECT"));
SelectItemGuiTestObject gto2 = (SelectGuiSubItemTestObject) list_viewFormList2View2();
gto2.select(dpString("Identity_Proven"));
}
The code keeps continuing in a similar fashion like this, but I can't get it working for every possible case due to 2 main reasons:
A) The object location isn't known until runtime.
B) The information provided on page 1 decides what the user will see on page 2.
Is there a better way to do this then adding several repeating sections of code as seen above? As there coulld be many, many listboxes to data-drive.
I've looked in many places for a solution, but I've really struggled to get this particular piece of logic working.
Any help given is greatly appreciated!
I don't really see what your code is supposed to do. In my opinion, boxes and boxes2 are the same objects, so list and list2 should be eqal too. Then you get two equal objects gto and gto2 from the Helper Class which are not related to the objects you searched before.
Regarding A) and B): Since it should be known in the testcase, which information is provided on page 1 it should also be given which listboxes are displayed on page 2. Or do I miss something?
If you want to prevent code duplication you need some kind of link between the listboxes and the datapool, eg.:
for (int i = 0; i < listboxes.length; i++) {
SelectGuiSubitemTestObject listbox = (SelectGuiSubitemTestObject)listboxes[i];
String listboxID = listbox.getProperty(".id").toString();
listbox.select(dpString(listboxID));
}
This takes the ID of a listbox and selects the value from the datapool which is stored with this ID. But I'm not sure whether this is what you need–sadly I have too little reputation to add comments to your question.
In order to provide better solution framework to your problem i would need to you to answer the following queries based on below scenario:
Consider the scenario where the user selects 2 radio buttons as true/yes , which results in 5 list-boxes/combo-boxes in the second page.
Do you know how many list-boxes will be there in next page? ( in this case 5)
Do you know what item is to be selected in each list-box? Is this data selection coming from a datapool or excel sheet?
If you don't know the answer to point 1 how mare you planning to select the items in the list-boxes . What i mean to ask is how would you know how much data you need to feed for this page from the datapool?
Depending on your answer i can suggest a framework or code snnipet.
Apologies for the vague title but this is a bit hard to explain... though I'll try my best!
I have a task to replicate some specific functionality on an application screen and thus while the method by which this is being done may seem odd, there is no allowance to variate from the specific task.
Firstly, all data is retrieved from an SQLite database. This retrieval part is no problem. The available columns in the database are:
pk (primary key)
heading_id
heading_name
sub_heading_name (can be duplicated on multiple rows with different contents)
sub_heading_contents
The final screen should display the following:
<heading_name>
<clickable List(View?) of abbreviated sub_heading_contents>
<next heading_name>
<next clickable list>
<etc...>
So basically just a list of headings and brief descriptions of sub_heading information. For instance, this might look like:
Food
Sticky Date Pudding is a...
Chocolate Cake tastes...
Ice Cream can be...
Pizza is often...
Pasta once was...
Burgers are...
Now, the weird thing is that while you see the list of sub heading details, when you click on any of them you are taken to a screen that shows information from every sub heading of the same name. In other words, clicking on the first 3 sub heading descriptions under food (pudding/cake/ice cream) would take you to another page under the sub heading name "Dessert" with all 3 descriptions listed on the same page, while clicking on the last 3 (pizza/pasta/burgers) would take you to a different page with the sub heading name "Mains". So you see all the sub heading descriptions in a big list in a seemingly unordered fashion but they are grouped by hidden sub heading names that are only apparent once you click on them to be taken to the next page.
So my problem now is... what would be the best way to store and reference the data retrieved from the database in order to create such a list? I've tried some variations of maps, treemaps, custom classes, lists, etc., but all seem to fall down at some point during the process (no doubt because I'm not using them properly!).
I wish I had some code to paste but it's all so disorganized at the moment I wouldn't even know where to start. Any even vague suggestions as to how such a thing might be accomplished would be greatly appreciated!
Thanks!
You appear to have a three-tier structure, of which only two tiers are directly user-visible. An example of this tiered structure, from your prose, is:
Food -> Dessert -> Pudding
For the purposes of this answer, I will call these the topLevel, midLevel, and detail tiers. I haven't the foggiest notion how this maps to your terms, as your prose suggests that both "Dessert" and "Pudding" are "sub headings", which muddies the waters. If "Pudding" appears in the UI, and "Dessert" does not, they are distinct things and should be treated as such in the data model.
Hence, this would appear to be three database tables, one for each tier, with classic 1:N foreign key relationships (i.e., the midLevel table has a column containing the key of the topLevel that contains it). Or, hold the entire tree representation in a separate file, in JSON or XML format, rather than a database.
From an in-memory data representation, a TopLevel holds a collection of MidLevel objects, each of which has a collection of Detail objects (again, using my terms, not yours).
In terms of UI, since you have elected to only show two tiers, you could use ExpandableListView, with TopLevel instances driving the parent nodes and the aggregate collection of Detail objects (for all MidLevel objects in the TopLevel) driving the child nodes.
The problem with your desired UI is that you have to have all of your TopLevel, MidLevel, and Detail objects in memory, at least to the level of knowing their parent-child relationships and enough data to drive the ExpandableListView UI. If your data model is big, this will be expensive.
JasperReports newbie here. I have read the tutorial and the quick reference and read up on a number of articles regarding JR, and have now been playing around with the iReport report designer for a day or so.
I think the last major set of concepts I am choking on have to do with the relationship between chart components and their data. Although it is easy to find definitions for each of these, there seems to be very little practicle documentation showing how they relate to one another in a meaningful application.
Report Fields
Report Prameters
Report Variables
Datasets
By playing around with iReport it seems that Fields, Parameters and Variables can exist at the report-level, as well as being placed inside of Datasets. But my understanding of when something is a Field vs. Parameter vs. Variable is very fuzzy, and my understanding of how they relate to Datasets is also very shaky.
Using Datasets as a slight segue, I'm having a tough time seeing the "forest through the trees" with how chart components (such as pie charts, tabls, etc.) get "fed" or "injected with" their data.
Soo... I thought of an example that, if answered, would tie everything together for me (I believe!). Let's say I had two chart components, a text field and a pie chart. I want the pie chart to appear below the text field like so:
The author of this report is: <value supplied by the data source>
<pie chart here>
So, at "fill time" (I think I'm using that correctly...), the report will be "filled" with the name of the report's author (a String), as well as a pie chart comprised of 2 pie slices: 1 slice with a value of 75 with a label/key of "Eloi" and a 2nd slice with a value of 25 and a label/key of "Morlocks". If I am not using the correct JR terminology here, what I am trying to achieve is a fill-time pie chart with two slices: an "Eloi" slice consuming 75% of the chart, and a "Morlocks" slice consuming 25% of the chart.
If someone can explain or give code (Java/JRXML) snippets for how to set this kind of chart up, I think it will help connect all the dots and help me understand how components get filled with data. Thanks in advance for any and all help!
Think of parameters as things that the end user supplies to the report at runtime. For example, you supply a StartDate and an EndDate that will get used in a query. The start date that you are interested in is something you know, it's not provided by the data source. (There are variations on this idea: maybe your application knows things about you based on your login, and it supplies these as parameters. But again, these are things known before the report is executed.)
Think of the fields as the data that comes back from your data source. This is the stuff that you want to learn. For example, you run a query like this:
select political_group, gullibility from mytable where the_date > $P{StartDate}
Presumably you would input a value of '802701' for the StartDate and then get results like this:
$F{political_group} $F{gullibility}
Eloi 75
Morlock 25
Think of variables as a way to manipulate this raw data. They can calculate totals and subtotals as well as line-by-line calculations like string manipulation or more complex things like running totals.
Take a look at this pie chart report I posted a couple of years ago: http://mdahlman.wordpress.com/2009/05/02/limiting-pie-pieces/
It has the main ideas you want. I put the title directly into the chart rather than as a separate field. That would be a very simple change. Likewise, you could change the title to "The author of this report is: $P{TheAuthor}" and then pass that param to the report at runtime.
Using a field in the report title rather than a parameter is possible also. But typically it doesn't make sense. The fields will have many values in the data set. Which one belongs in the title? In the case above "Eloi" and "Morlock" are fields, and they really don't make sense in the report title. (You can imagine special cases, of course. You could concatenate all of the political_group values into a single string and put that in the report title. But in an overwhelming majority of cases this won't be reasonable.)
Good luck.