JSF best practices : One form for the whole application or a few smaller forrms? -

what best practice in jsf , create 1 main <h:form> in template example , put content inside or have few forms each parts, example if have 2 logical blocks of code on page should have wrapped these blocks in 2 separate forms ???

this overly broad question, , has nothing di jsf. question of html understanding , design.

if abstract away of jsf details, you'll find out rendered component plain html <form>. recall specification, form is:

a section of document containing normal content, markup, special elements called controls (checkboxes, radio buttons, menus, etc.), , labels on controls. users "complete" form modifying controls (entering text, selecting menu items, etc.), before submitting form agent processing (e.g., web server, mail server, etc.)

so a whole form submitted server. in case of component-based framework, jsf, bound values of components populate backing beans submitted data, in case there no errors.

but data submitted? data within form. so, if have 1 global form means all unrelated pieces of information collected: user credentials, product choices, selection of preferences, etc. , done @ once. won't yield desired functionality, produce unexpected results.

the problem there mixing of concerns: 1 form contained non-related data was not designed submitted together. leaves one-form-per-user-interaction, 1 form user authentication/logout, form storing user preferences, yet 1 keeping product choices, etc. 1 global form leave nesting forms problem, taking time figure out.

regarding choice of put form, depending on logical separation: if have user login/logout on every page placed in master template. per-view forms put in template client. moreover, you'll find convenient put them side-by-side distinguish functionality.

also, form may alter expected behaviour. 1 final example: user choice of products. consider 2 cases.

the first one:

<h:form>     <ui:repeat value="#{bean.purchasedproducts}" var="product">         <h:outputtext value=#{product.name}/>         <h:inputtext value=#{product.quantity}/>         <h:commandbutton value="change"/>     </h:datatable> </h:form> 

the second one:

<ui:repeat value="#{bean.purchasedproducts}" var="product">     <h:form>         <h:outputtext value=#{product.name}/>         <h:inputtext value=#{product.quantity}/>         <h:commandbutton value="change"/>     </h:form> </h:datatable> 

while first example update all products, second 1 update only relevant product.

finally, there no 'best practice' or 'universal solution'. think it's best depart separation of concerns when designing html document.

and, yes, i'm voting close question.