Way to filter a Salesforce report by a list of values

apex-codefilterreportingsalesforce

Ok, so I want to have a report that does not require the end user to know all about writing and customizing reports or memorizing field values. I ultimately want the user to be able to use a collection of prepopulated SelectList based filters on an apex page I've created to filter their report.

So far I have this as far as being able to filter by one value for each field:

Create an Account report
Add a filter for BillingState Equals blank (This is filter #1, or index 0)
Create a Page with a SelectList and use a Controller to populate it with a list of States
Create a CommandButton on the page and use a PageReference object to redirect to the Report
At the end of the URL for the report, add pv0 (parameter value for index 0) = [selected state]

So this is all well and good – instead of having the user memorize valid field values and mess with report filters they can point and click stuff – so simple a sales person could do it.

But now I want to filter by a list of states (or some other text field). I can easily get a String[] list of states with the multiselect attribute of the SelectList, but I don't know how to go about applying it to the report. In an SQL sense I want add a "State=x OR State=y OR State=Z" or "State IN (x, y, z)" where condition to the reports query.

How could I go about doing this – filtering a report by a list of valid values for a field, and doing it programmably from a controller?

Is there some method to programmably create a temporary report on the fly? Clone a "template" report and then add OR filters as needed?
Is there a way to pass a set of objects to a report? Some reports return a lot of results, so this seems dangerous.
When doing PageReference redirection the Redirect attribute states that when it is false all the state information is retained, but the destination page must have the same controller – is there a way to use controllers with reports to customize their logic?

Best Answer

If I get you right, you're almost there.

Add your criteria values comma separated to the appropriate URL parameter. In your example, the pv0 URL parameter:

/[your-report-id]?pv0=OR,FL

Related Solutions

Java – How to filter a Java Collection (based on predicate)

Java 8 (2014) solves this problem using streams and lambdas in one line of code:

List<Person> beerDrinkers = persons.stream()
    .filter(p -> p.getAge() > 16).collect(Collectors.toList());

Here's a tutorial.

Use Collection#removeIf to modify the collection in place. (Notice: In this case, the predicate will remove objects who satisfy the predicate):

persons.removeIf(p -> p.getAge() <= 16);

lambdaj allows filtering collections without writing loops or inner classes:

List<Person> beerDrinkers = select(persons, having(on(Person.class).getAge(),
    greaterThan(16)));

Can you imagine something more readable?

Disclaimer: I am a contributor on lambdaj

Python – List comprehension vs. lambda + filter

It is strange how much beauty varies for different people. I find the list comprehension much clearer than filter+lambda, but use whichever you find easier.

There are two things that may slow down your use of filter.

The first is the function call overhead: as soon as you use a Python function (whether created by def or lambda) it is likely that filter will be slower than the list comprehension. It almost certainly is not enough to matter, and you shouldn't think much about performance until you've timed your code and found it to be a bottleneck, but the difference will be there.

The other overhead that might apply is that the lambda is being forced to access a scoped variable (value). That is slower than accessing a local variable and in Python 2.x the list comprehension only accesses local variables. If you are using Python 3.x the list comprehension runs in a separate function so it will also be accessing value through a closure and this difference won't apply.

The other option to consider is to use a generator instead of a list comprehension:

def filterbyvalue(seq, value):
   for el in seq:
       if el.attribute==value: yield el

Then in your main code (which is where readability really matters) you've replaced both list comprehension and filter with a hopefully meaningful function name.

Best Answer

Related Solutions

Java – How to filter a Java Collection (based on predicate)

Python – List comprehension vs. lambda + filter

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