add line: placeholder Ztal_Tales_Form.getAttrib:element,string:placeholder
for support this attribute
<!-- Will display an <input> element -->
<input metal:define-macro="inputElement"
tal:attributes="type Ztal_Tales_Form.inputType:element;
name name | element/getFullyQualifiedName;
id element/getId;
class Ztal_Tales_Form.getAttrib:element,string:class;
value value | nothing;
maxlength Ztal_Tales_Form.getAttrib:element,string:maxlength;
checked checked | nothing;
autocomplete Ztal_Tales_Form.getAttrib:element,string:autocomplete;
disabled Ztal_Tales_Form.isDisabled:element;
placeholder Ztal_Tales_Form.getAttrib:element,string:placeholder"
/>
add line: placeholder Ztal_Tales_Form.getAttrib:element,string:placeholder for support this attribute