Freemarker, looping sequence with one object/multiple attributes - freemarker

I am working on looping through one object with multiple attributes. In my scenario, I am looking for external content values.
email_address
article01
article02
article03
email#address.com
Y
Y
These values can change all the time, so we have to define them manually every instance where we use this, but I want to be able to list them in a sequence and then loop through and include them when object.attribute=Y.
The below block is purely conceptual, but referencing the attribute within the expression is where I get confused.
<#assign seq = ['article01','article02','article03']>
<#list seq as articles>
<#if base.${article}="Y">
<#include "*/${article}.htm"/>
</#if>
</#list>
In this instance, the resulting code would be:
<html><article01.html content></html>
<html><article03.html content></html>

Assuming base.articel01 would work, you can use base[article] (instead of base.${article}).

Related

Trying to generate a string that becomes a variable name in Freemarker or a "derived variable name"

I'm using a data-directive or list to pull in several values, of which, I don't know how many there will be, and I want to try and list through them, and create several variables in the list if you will.
<#list 1..10 as x>
<#-- the next line doesn't work, but what i'm trying to fix -->
<#assign .vars['VAR'+x?string] = rand(100) />
</#list>
But I can list them back out that way.
<#list 1..10 as x>
${.vars['VAR'+x?string]}
</#list>
The documentation for assign, says:
name: name of the variable. It is not expression. However, it can be
written as a string literal, which is useful if the variable name
contains reserved characters, for example <#assign "foo-bar" = 1>.
Note that this string literal does not expand interpolations (as
"${foo}").
Is there no way around this? Am I trying to do the impossible? Is there some way I can insert a derived name into the .vars... Hash is it?
A little more research that was close, but didn't get me there:
This prevoius question gives how to READ the derived variable, but I need to WRITE/CREATE the derived variable.
FreeMarker get variable value by concatenating another variable value
This prevoius question shows that I can use a string to assign a variable and re-iterates what we saw in the first link.
Variable name in Freemarker Template Language
As FreeMarker can't assign to elements of collections (but you can ?map(it -> ...) a collection to another), the only way is via ?interpret:
<#list 1..10 as x>
<#-- the next line doesn't work, but what i'm trying to fix -->
<#'<#assign VAR${x?c} = rand(100)>'?interpret />
</#list>
I wonder why do you need to assign to a dynamically named variables though, since reading dynamically named variables is also a pain, even if a lesser one.
Ultimately, I believe the correct way to phrase my solution was a sequence of hashes:
<#list 1..z_Coupon_Pet.NUM_COUPONS as x>
<#assign INSTORE_COUPON=call_coupon_from_table1() />
<#assign ONLINE_COUPON=call_coupon_from_table2() />
<#assign coupon_string_row= '{
"COUPON_NUM" : ${x},
"INSTORE" : "${INSTORE_COUPON?js_string}",
"ONLINE" : "${ONLINE_COUPON?js_string}"
}' />
<#if x==1>
<#assign coupon_hash_string = coupon_string_row />
<#else>
<#assign coupon_hash_string = coupon_hash_string + ',' + coupon_string_row />
</#if>
</#list>
</#if>
<#if coupon_hash_string?has_content>
<#assign coupon_hash=parsejson('[' + coupon_hash_string + ']') />
</#if>
We specifically avoid <#assign my_hash = my_hash + element /> because of this note in the documentation:
Note that hash concatenation is not to be used for many repeated concatenations, like for adding items to a hash inside a loop. While adding together hashes is fast and is constant time (independent of the size of the hashes added), the resulting hash is a bit slower to read than the hashes added together. Thus after tens... of additions the result can be impractically slow to read.

How to create a csv output with freemarker?

The input to my freemarker template is records: List<List<String>> records = new ArrayList();
each list inside records is a row from a database;
I need to create a csv;
How I can write values of a row in a separate line to create a csv.
Here is my freemarker template:
for now it write any value in a different line.
<#list records>
<#items as record>
<#list record>
<#items as value>
${value},
</#items>
</#list>
</#items>
</#list>
``````````
In simple cases #items is not needed, so I give the example without that (but same approach works with #items as well).
<#list record as value>${value}<#sep>,</#list>
That is, #list (and #items) just repeatedly prints the content nested between its start tag and end tag (except, it ignores the line-break directly after the start tag). So if you don't have a line-break at the end of the nested content, then it doesn't print a line-break.
As of #sep, I added that because you don't want comma after the last value of the record.

filter freemarker output by hash

<#list reports as report>
<#list report.transactionList as expense>
${expense.transactionID}^<#t>
${table[expenses.transcationID}
<#if expense.modifiedCreated?has_content>
${expense.modifiedCreated}^<#t>
<#else>
${expense.created}^<#t>
</#if>
In the above code I have a hash table called table and I want to use expense.transactionID as the key to then load the table's value like in the above code.
when I run it, the second item instead of a value is just a blank spot.
figured it out. {table[expenses.transcationID} needs to cast the category I am using as the key into a string. so the answer is: {table[expenses.transcationID?string}

Freemarker - How to put variables in hashmap?

I searched the web to find how to add some entries into an existing hashmap.
Consider this code:
<#assign foo={'bar':'go'}>
I want to add a new entry and have something like this:
foo={'bar':'go','new':'entry}
How can I do that?
Using concatenation:
<#assign foo=foo+{'new':'entry'}>
print the hashmap:
<#list foo?keys as k>
${k}: ${foo[k]} <br>
</#list>
The result is exactly what you want:
bar: go
new: entry
D.

Handling null values in Freemarker

How to handle null values in Freemarker? I get some exceptions in the template when null values are present in data.
Starting from freemarker 2.3.7, you can use this syntax :
${(object.attribute)!}
or, if you want display a default text when the attribute is null :
${(object.attribute)!"default text"}
You can use the ?? test operator:
This checks if the attribute of the object is not null:
<#if object.attribute??></#if>
This checks if object or attribute is not null:
<#if (object.attribute)??></#if>
Source: FreeMarker Manual
I think it works the other way
<#if object.attribute??>
Do whatever you want....
</#if>
If object.attribute is NOT NULL, then the content will be printed.
Use ?? operator at the end of your <#if> statement.
This example demonstrates how to handle null values for two lists in a Freemaker template.
List of cars:
<#if cars??>
<#list cars as car>${car.owner};</#list>
</#if>
List of motocycles:
<#if motocycles??>
<#list motocycles as motocycle>${motocycle.owner};</#list>
</#if>
I would like to add more context if you have issues and this is what I have tried.
<#if Recipient.account_type?has_content>
… (executes if variable exists)
<#else>
… (executes if variable does not exist)
</#if>
This is more like Javascript IF and ELSE concept where we want to check whether this value or another chaining through required logic.
Freemarker webite
Other reference:
Scenario: Customer has ID and name combined like 13242 Harish, so where our stakeholder need the only name, so I have tried this ${record.entity?keep_after(" ")} and it did work, however, it can only work when you have space, but when a customer doesn't have space and one name, I had to do some IF ELSE condition to check Null value.
Use:
${(user.isSuperman!false)?c}
It will work when "isSuperman" is null and when have boolean value
What we want:
For "null" we want to output 'false'
For boolean value and want to output value ('true' or 'false')
What we know:
boolean need to convert to string by using "?c" see Built-ins for booleans
but null we cannot convert to string and we need to use "!" see Handling missing values

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