Check if FreeMarker #nested directive is empty - freemarker

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 != ''>.

Related

Freemarker - is nested if allowed inside else (not the common if elseif...elseif else)

I am not asking about the common nesting in freemarker (which I know for sure is supported) :
<#if cond1> do abc
<#elseif cond2> do xxx
<#elseif cond3> do yyy
<#else> do zzz
</#if>
Want to know if the below nesting is supported in freemarker:
<#if cond1> do abc
<#else>
<#if cond-X> do xxx </#if>
<#if cond-Y> do yyy </#if>
<#if cond-Z> do zzz </#if>
</#if>
Note that I have multiple if conditions inside the else.
My code throws error
Error detail: Syntax error in template "template" in line 1282, column 45: Unexpected directive, "</#if>". Check if you have a valid #if-#elseif-#else structure.
So I suspect the latter type of nesting provided by my architect.
It is supported, and what you show is parsed successfully for me. Maybe the error is elsewhere, or you aren't looking at the template that's actually processed?

String replace in FTL with a specific word

I need to replace a specific string in a URL in FTL.
Code 1:
<#assign pageUrlWithParams= "https://sample.com/category?filter=low&navParam=Appliances&skrLocale=en_US&t=1"/>
<#if pageUrlWithParams?? && pageUrlWithParams != '' && pageUrlWithParams?contains("skrLocale")>
<#assign pageUrlWithParams = pageUrlWithParams?replace('skrLocale','')/>
</#if>
${pageUrlWithParams}
Code 2 :
<#assign pageUrlWithParams= "https://sample.com/category?filter=low&navParam=Appliances&skrLocale=en_FR&t=2"/>
<#if pageUrlWithParams?? && pageUrlWithParams != '' && pageUrlWithParams?contains("skrLocale")>
<#assign pageUrlWithParams = pageUrlWithParams?replace('skrLocale','')/>
</#if>
${pageUrlWithParams}
I need to remove "skrLocale=en_US" and "skrLocale=en_FR" from pageUrlWithParams.
Known text is "skrLocale", using this I need to remove "skrLocale=en_US" and "skrLocale=en_FR".
Because of en_US and en_FR, i dont know how to take that that part after equals.
Some suggest an answer please. Thanks in advance
Using regular expressions ('r' as 3rd parameter to ?replace) is the key. Note that due to the complexity of URL syntax, we need to handle two edge cases (skrLocale is the first parameter, and skrLocale is the only parameter), which the below function fulfills. However, it doesn't handle %xx escapes in the parameter name (which you might don't care about):
<#function removeSkrLocale url>
<#return url?replace(r'([&\?])skrLocale=[^&]*&?', '$1', 'r')?remove_ending('?')>
</#function>
${removeSkrLocale(pageUrlWithParams)}
Of course you can do this without #function as well, directly inside the ${}, but it's reusable and more self documenting this way.
I would use a Freemarker function (this is a simple version, can be improved)
<#function remove_param_if_value_equals pageUrlWithParams paramName, paramValues >
<#if pageUrlWithParams?has_content && pageUrlWithParams?contains(paramName)>
<#list paramValues as paramValue>
<#local paramNameAndValue = paramName + "=" + paramValue />
<#local pageUrlWithParams = pageUrlWithParams?replace(paramNameAndValue,'')/>
</#list>
</#if>
<#return pageUrlWithParams />
</#function>
<#assign pageUrlWithParams= "https://sample.com/category?filter=low&navParam=Appliances&skrLocale=en_US&t=1"/>
<#assign pageUrlWithParams = remove_param_if_value_equals(pageUrlWithParams, "skrLocale", ["en_US", "en_FR"]) />
${pageUrlWithParams}
The code that does the business remains isolated and can be altered/improved later on.
(For example there is that double "&" that could be cleaned)
I don't know about FTL. But if you need to replace parameter skrLocale in your URL, I think below is good pattern you can use:
(skrLocale(.*?)&)
With (.*?) is called lazy, it match from skrLocale to nearest &. Therefore, with your case, it will match skrLocale=en_US& and skrLocale=en_FR& .

How to DUMP object in freemarker ( .ftl )

is there a way how to dump whole object and write it somewhere?
Like:
var_dump() in php
console.log in JS
I found something like list, so I try something like this below:
<#list calculation as c>
${c}
</#list>
But template fall with error. I appriciate any advise!
It depends on the type of object you are iterating through. You can check the type of data your variable is and then output it appropriate (Reference: http://freemarker.incubator.apache.org/docs/ref_builtins_expert.html#ref_builtin_isType)
Here are some examples:
<#if calculation?is_sequence>
<#list calculation as c>
${c}
</#list>
<#elseif calculation?is_hash_ex>
<#list calculation?keys as key>
${key} - ${calculation[key]}
</#list>
<#elseif calculation?is_string>
${calculation}
</#if>
Take a look at https://github.com/ratherblue/freemarker-debugger/blob/master/debugger.ftl for more examples on dumping data

does freemarker support show all variable in data-model?

I want to see all variables in freemarker data-model, just like struts2 debug tag to show value stack.
Is there a way for freemarker to do this ?
There's no universal solution possible for that, but you can try
<#list .data_model?keys as key>
${key}
</#list>
This works if the data-model is just a usual Map or JavaBean, but for more sophisticated data-models it's up to the data-model implementation if it supports ?keys and if it indeed returns everything.
You also have the variables that you set in the templates, which can be listed like above, only instead of .data_model use .globals, .namespace (which means the current template namespace) and .locals.
You may also have Configuration-level shared variables, and there's no way to list those purely from FTL (you could write a custom TemplateMethodModel for it that reads Configuration.getSharedVariableNames() though, and call it from the template).
Of course, ideally, FreeMarker should have a <#show_variables> directive or something, that does a best effort to show all this... but sadly there is no such thing yet.
An even more detailed way would be this macro:
<#macro dump_object object debug=false>
<#compress>
<#if object??>
<#attempt>
<#if object?is_node>
<#if object?node_type == "text">${object?html}
<#else><${object?node_name}<#if object?node_type=="element" && object.##?has_content><#list object.## as attr>
${attr?node_name}="${attr?html}"</#list></#if>>
<#if object?children?has_content><#list object?children as item>
<#dump_object object=item/></#list><#else>${object}</#if> </${object?node_name}></#if>
<#elseif object?is_method>
#method
<#elseif object?is_sequence>
[<#list object as item><#dump_object object=item/><#if !item?is_last>, </#if></#list>]
<#elseif object?is_hash_ex>
{<#list object as key, item>${key?html}=<#dump_object object=item/><#if !item?is_last>, </#if></#list>}
<#else>
"${object?string?html}"
</#if>
<#recover>
<#if !debug><!-- </#if>LOG: Could not parse object <#if debug><pre>${.error}</pre><#else>--></#if>
</#attempt>
<#else>
null
</#if>
</#compress>
</#macro>
<#dump_object object=.data_model/>
This gives you a full dump of your data model.
Here is #lemhannes macro definition modified to emit JSON. Lightly tested on a fairly simple datamodel
<#macro dump_object object debug=false>
<#compress>
<#if object??>
<#attempt>
<#if object?is_node>
<#if object?node_type == "text">${object?json_string}
<#else>${object?node_name}<#if object?node_type=="element" && object.##?has_content><#list object.## as attr>
"${attr?node_name}":"${attr?json_string}"</#list></#if>
<#if object?children?has_content><#list object?children as item>
<#dump_object object=item/></#list><#else>${object}</#if>"${object?node_name}"</#if>
<#elseif object?is_method>
"#method"
<#elseif object?is_sequence>
[<#list object as item><#dump_object object=item/><#if !item?is_last>, </#if></#list>]
<#elseif object?is_hash_ex>
{<#list object as key, item>"${key?json_string}":<#dump_object object=item/><#if !item?is_last>, </#if></#list>}
<#else>
"${object?string?json_string}"
</#if>
<#recover>
<#if !debug>"<!-- </#if>LOG: Could not parse object <#if debug><pre>${.error}</pre><#else>-->"</#if>
</#attempt>
<#else>
null
</#if>
</#compress>
</#macro>

Is it possible to have freemarker's <#spring.showErrors to display errors in a div instead of span

Code:
<#spring.formInput 'myForm.spouseEmail' 'id="spouseEmail" class="text"'/>
<#spring.showErrors ', ' 'error'/>
Output:
<span class="error">not a well-formed email address</span>
What I want:
<div class="error">not a well-formed email address</div>
#Mike: it seems you have troubles understanding the nature of macros. They are already-written freemarker script to make your life easier. You can always write a customed one.
Some people think it obvious, but I myself find that it's not easy to know how to view the spring-freemarker macros source code. You can navigate to package org/springframework/spring-webmvc-3.0.5.jar/org/springframework/web/servlet/view/freemarker/spring.ftl in Eclipse's "Referenced Libraries".
Here's the macro "showErrors" gotten from "spring.ftl":
<#macro showErrors separator classOrStyle="">
<#list status.errorMessages as error>
<#if classOrStyle == "">
<b>${error}</b>
<#else>
<#if classOrStyle?index_of(":") == -1><#assign attr="class"><#else><#assign attr="style"></#if>
<span ${attr}="${classOrStyle}">${error}</span>
</#if>
<#if error_has_next>${separator}</#if>
</#list>
</#macro>
To achieve your goal, it's very simple: just write a custom macro which is exactly like the code above, replace span by div
No, but you can easily write your own macro to do whatever you want. Get your inspiration from spring.showErrors itself.

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