Defer variable parsing in Freemarker - freemarker

I need to defer the parsing of a variable that is in the top of the document so as to modify its content and then output its value it at the end of the process.
I'm using latest Freemarker version
For example:
<#global myVar="">
// Output here
${myVar} <<<<< DEFER HERE!
// Some other work ...
// Change its value
<#global myVar="Correct">
should output
Correct

There's no such feature. Depending on the use case, what's sometimes working is capturing the output starting from the position where the deferred part will be, and then printing the deferred part, and then printing the captured output. For example you need to print the number of some items at the top of a section, but the items will be only known after the section was printed. Then:
<#macro sectionWithCounterOnTop>
<#assign itemCount = 0>
<#local sectionContent><#nested></#local>
Items: ${itemCount}
${sectionContent}
</#macro>
<#macro item>
<#assign itemCount++>
</#macro>
and then:
<#sectionWithCounterOnTop>
...
<#item />
...
</#sectionWithCounterOnTop>

Related

Check if FreeMarker #nested directive is empty

I want to output tags around a <#nested> directive in a macro, but only if it would actually output something. The actual use case is more complicated, this is just the broken down version.
How do I check for existence of <#nested> content?
<#macro opt tagname>
<#if (#nested)??> <-- what do I need to put here
<${tagname}>
<#nested>
</${tagname}>
</#if>
</#macro>
Example 1
Template: <#opt hello />
Output: (empty)
Example 2
Template: <#opt hello>goodbye</#opt>
Output: <hello>goodbye</hello>
You have to capture the nested content, and then print it if necessary. Like this (this assumes auto-escaping on):
<#macro opt tagname>
<#local nestedContent><#nested></#local>
<#if nestedContent?has_content>
<${tagname}>${nestedContent}</${tagname}>
</#if>
</#macro>
Without auto-escaping the #if changes to just <#if nestedContent != ''>.

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.

Freemarker, looping sequence with one object/multiple attributes

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}).

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.

freemarker how to use split in string which is readed with include

<#assign reasonValue="xxx.ftl">
and I call it like:
<#include "${reasonValue}">
and I get output like:
Rejected - Something
how can I now use split on this ouput because I would like to get just Something as output
I tried:
<#list "${reasonValue}"?split("-") as sValue>
${sValue}
</#list>
but problem is that instead of real value i get name of ftl file...
Assign output of include to some variable and then use split on this variable.
<#assign xx>
<#include reasonValue>
</#assign>
<#list xx?split("-") as sValue>
${sValue}
</#list>
If you need to show only part of the string after "-" then use substring and index_of.
${xx?substring(xx?index_of("-") + 2)}

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