text_field_tag(要素名, value値=nil, オプション={}, HTML属性={} or イベント属性={})
text_field_tag 'name'
#=> <input id="name" name="name" type="text" />
text_field_tag 'query', 'Enter your search query here'
#=> <input id="query" name="query" type="text" value="Enter your search query here" />
text_field_tag 'search', nil, placeholder: 'Enter search term...'
#=> <input id="search" name="search" placeholder="Enter search term..." type="text" />
text_field_tag 'request', nil, class: 'special_input'
#=> <input class="special_input" id="request" name="request" type="text" />
text_field_tag 'address', '', size: 75
#=> <input id="address" name="address" size="75" type="text" value="" />
text_field_tag 'zip', nil, maxlength: 5
#=> <input id="zip" maxlength="5" name="zip" type="text" />
text_field_tag 'payment_amount', '$0.00', disabled: true
#=> <input disabled="disabled" id="payment_amount" name="payment_amount" type="text" value="$0.00" />
text_field_tag 'ip', '0.0.0.0', maxlength: 15, size: 20, class: "ip-input"
#=> <input class="ip-input" id="ip" maxlength="15" name="ip" size="20" type="text" value="0.0.0.0" />