Why use <g:textField /> in Grails? - grails

What is the reason to use g:textField in Grails if you're already familiar with standard HTML form tags?
If I understand correctly the following two markup alternatives are equivalent:
<input type="text" name="name" value="${params.name}" id="name" />
<g:textField name="name" value="${params.name}" />
Are there any circumstances under which using g:textField would add value? Am I missing something?

The textField tag is provided as a convenience (slightly shorter than writing the HTML input) and is there to provide a full set of form tags. Personally I prefer to write as much plain HTML as possible in my Grails views and only tend to use the tags that really offer a benefit such as the form tag. I have not found an instance where using textField would have added any value outside of requiring a few less characters to type.

<g:textField /> is not shorter as plain text field tag, except id attribute will be attached automatically.
However, I recommend you to use customized tags associating the bean values with input fields. That shortens the code a lot. For more information you can read http://www.jtict.com/blog/shorter-grails-textfield/
Also you can find useful stuff in Form Helper Plugin

Related

Ruby - Set of inputs to array

I'm trying to have a dynamic set of inputs in a form, that start with just one, where you can add or remove them with add/delete buttons. Then upon submission of a form, it turns the values of the inputs into a hash then that hash into a string for storing. I really have no idea where to start. So any tips will be helpful.
If using javascript would help, I can go that route, but i'm not sure how to make the javascript and ruby talk.
Depending on your use-case, there are a few options you might want to use. Since you've tagged this with rails, I'm assuming you have access to JQuery. Here's one (very simple) example of how you might go about adding fields to the page dynamically using it:
https://jsfiddle.net/3Lyvw0jm/
If you plan on storing these fields in one of your models, you may want to take a look at implementing nested attributes.
As pretty much a common web thing (not Rails-specific), you would make the name value look like some_name[].
So instead of having multiple inputs with different names like this:
<input type='text' id='my_input_1' name='my_input_1' value='string_1' />
<input type='text' id='my_input_2' name='my_input_2' value='string_2' />
<input type='text' id='my_input_3' name='my_input_3' value='string_3' />
...where on the server you get:
params :my_input_1 # 'string_1'
params :my_input_2 # 'string_2'
params :my_input_3 # 'string_3'
You would have:
<input type='text' id='my_input_1' name='my_inputs[]' value='string_1' />
<input type='text' id='my_input_2' name='my_inputs[]' value='string_2' />
<input type='text' id='my_input_3' name='my_inputs[]' value='string_3' />
...where on the server you get:
params :my_inputs # ['string_1','string_2',string_3']

Use placeholders with <f:all bean />

In Grails, you can generate a form using <f:all bean="beanName" />. And while the generated form looks great, I was wondering if it would be possible to have a placeholder in the field, so that the result becomes something like:
<input type="text" name="question" placeholder="type your question here" />
I tried using the attributes validation in Grails, like this:
class Question {
static constraints = {
question(size:5..100, attributes:[placeholder:"type your question here"])
}
}
But it doesn't seem to have any effect on the generated HTML.
Just in case there's any confusion, the f:all tag is provided by the fields plugin. I don't think there's any way you can specify the placeholder attribute via the domain class constraints, but there are a few other options.
One option is to define a custom (GSP) template for this property and specify the placeholder attribute therein. The path to this template will depend on which version of the plugin you're using, but you can find the details here.
Alternatively, if you render each field individually with f:field, rather than using f:all you can pass additional attributes to the input field, e.g.
<f:field bean="person" property="gender"
widget-placeholder="type your question here"/>
In earlier versions of the plugin (before 1.5), the attribute should be named input-placeholder instead, e.g.
<f:field bean="person" property="gender"
input-placeholder="type your question here"/>

What is the equivalent of HTML'S input tag in Rails?

I want to be able to generate this
<input id="address" type="textarea" value="Write your Address here.">
Using some ruby form helpers.
Any hints ?
I assume you meant textarea since there is no such thing as textbox.
http://apidock.com/rails/ActionView/Helpers/FormTagHelper/text_area_tag
if it's not tied to a field in your model
http://apidock.com/rails/ActionView/Helpers/FormHelper/text_area
if it is.

Why doesn't TextBoxFor include validation elements if called twice for the same model property?

Simple question... Here is an example of some razor code:
#Html.TextBoxFor(c => c.RevisedEstimate)
#Html.TextBoxFor(c => c.RevisedEstimate)
Here is how this renders:
<input data-val="true" data-val-number="The field Revised Estimate must be a number." id="RevisedEstimate" name="RevisedEstimate" type="text" value="0" />
<input id="RevisedEstimate" name="RevisedEstimate" type="text" value="0" />
The obvious question you ask is, "Why are you doing that?". The razor view is actually building client side detail-row templates that are used in KendoUI grids. There are two similar grids and we use the same viewmodel server side. We actually do provide the id element for the template so each field in each row ends up with a unique id.
Why does the second input element not have the data-val and data-val-number elements?
Off the top of my head knowing what the JS does in the background, it seems to do this to prevent conflicts. The JS looks for the elements with the data- attributes to do it's validation, along with other functions, so it could possibly pick the wrong one if there are multiple instances of it.
since we were generating HTML for use in a client side template what we did was just create a variable to hold the HTML generated by the helper, and then render out that code in the Views..
Something like:
#{
var revisedEstimateInput = Html.TextBoxFor(c => c.RevisedEstimate)
}
Then later in the view:
#(revisedEstimateInput)
...in as many places as needed. This way the validation and other metadata attributes were in place in our client templates and all the kenodUI validation worked correctly.

Can i use html tags in struts2 form?

Can i use html form tags in struts 2 form?
Like
<input type='text' value='' />
<input type='submit' />
Will the values be posted through struts2?
It's not at all mandatory to use struts2 tags. You could go with regular HTML.
Of course.
This is one of those questions you can just try.
All the S2 form tags do is emit HTML, filling in various attributes as required. (It's slightly more complicated than that, but ultimately, they spit out an HTML form field.)
Flip your question on its head: why wouldn't a hand-crafted input tag be sent via the normal browser HTTP submission process? What mechanism could prevent it from working? How is the request body of from such a form submission different from one where the input tags are S2 custom tags?
These questions are all trivial to explore.
Yes.
You must give them a name; the name will be used to set properties (with correct type conversion) in the struts action.
If you call an input somename the setSomename() will be called on post.
If simple HTML used you wont be able to call struts tags inside it eg:
<s:submit cssStyle="submit_button" id='newrc%{#stat.index}.%{#questionIndex.index}' name="newrc%{#stat.index}.%{#questionIndex.index}" onclick="return newrcClick(this)" value="+" />
This works but below code does not provide values for id and name from values stack thus :name="newrc%{#stat.index}.%{#questionIndex.index}"
<input type="button" cssStyle="submit_button" id='newrc%{#stat.index}.%{#questionIndex.index}' name="newrc%{#stat.index}.%{#questionIndex.index}" onclick="return newrcClick(this)" value="+" />

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