FormFieldsTagLib.groovy

/*
 * Copyright 2012 Rob Fletcher
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package grails.plugin.formfields

import grails.core.GrailsApplication
import groovy.transform.CompileStatic
import groovy.util.logging.Slf4j
import groovy.xml.MarkupBuilder
import org.apache.commons.lang.StringUtils
import org.grails.buffer.FastStringWriter
import org.grails.datastore.mapping.model.MappingContext
import org.grails.datastore.mapping.model.PersistentEntity
import org.grails.datastore.mapping.model.PersistentProperty
import org.grails.datastore.mapping.model.types.*
import org.grails.encoder.CodecLookup
import org.grails.gsp.GroovyPage
import org.grails.scaffolding.model.DomainModelService
import org.grails.scaffolding.model.property.Constrained
import org.grails.scaffolding.model.property.DomainPropertyFactory
import org.grails.web.servlet.mvc.GrailsWebRequest
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.beans.factory.annotation.Value
import org.springframework.context.MessageSource
import org.springframework.context.MessageSourceResolvable
import org.springframework.context.NoSuchMessageException
import org.springframework.web.servlet.LocaleResolver

import javax.servlet.http.HttpServletRequest
import java.sql.Blob
import java.text.NumberFormat

import static FormFieldsTemplateService.toPropertyNameFormat

@Slf4j
class FormFieldsTagLib {
	static final namespace = 'f'

	static final String STACK_PAGE_SCOPE_VARIABLE = 'f:with:stack'
	private static final List<String> DECIMAL_TYPES = ['double', 'float', 'bigdecimal']

	private static final String THEME_ATTR = "theme"
	private static final String WIDGET_ATTR = "widget"
	private static final String WRAPPER_ATTR = "wrapper"
	private static final String TEMPLATES_ATTR = "templates"
	private static final String PROPERTY_ATTR = "property"
	private static final String BEAN_ATTR = "bean"
	public static final String DISPLAY_STYLE = 'displayStyle'

	@Value('${grails.plugin.fields.localizeNumbers:true}')
	Boolean localizeNumbers

	FormFieldsTemplateService formFieldsTemplateService
	BeanPropertyAccessorFactory beanPropertyAccessorFactory
	DomainPropertyFactory fieldsDomainPropertyFactory

	@Autowired(required = false)
	Collection<MappingContext> mappingContexts

	DomainModelService domainModelService
	LocaleResolver localeResolver
	CodecLookup codecLookup
	MessageSource messageSource

	static defaultEncodeAs = [taglib: 'raw']

	class BeanAndPrefix {
		Object bean
		String prefix
		Map<String, Object> innerAttributes = [:]
	}

	class BeanAndPrefixStack extends Stack<BeanAndPrefix> {
		Object getBean() {
			empty() ? null : peek().bean
		}

		String getPrefix() {
			empty() ? null : peek().prefix
		}

		Map<String, Object> getInnerAttributes() {
			empty() ? [:] : peek().innerAttributes
		}

		String toString() {
			bean?.toString() ?: ''
		}
	}

	BeanAndPrefixStack getBeanStack() {
		if (!pageScope.hasVariable(STACK_PAGE_SCOPE_VARIABLE)) {
			pageScope.setVariable(STACK_PAGE_SCOPE_VARIABLE, new BeanAndPrefixStack())
		}
		pageScope.variables[STACK_PAGE_SCOPE_VARIABLE]
	}

	/**
	 * @attr bean REQUIRED Name of the source bean in the GSP model.
	 * @attr prefix Prefix to add to input element names.
	 */
	def with = { attrs, body ->
		if (!attrs[BEAN_ATTR]) throwTagError("Tag [with] is missing required attribute [$BEAN_ATTR]")
		BeanAndPrefix beanPrefix = resolveBeanAndPrefix(attrs[BEAN_ATTR], attrs.prefix, attrs)
		try {
			beanStack.push(beanPrefix)
			out << body()
		} finally {
			beanStack.pop()
		}
	}

	/**
	 * @attr bean REQUIRED Name of the source bean in the GSP model.
	 * @attr order A comma-separated list of properties to include in provided order
	 * @attr except A comma-separated list of properties to exclude from the generated list of input fields
	 * @attr prefix Prefix to add to input element names.
	 */
	def all = { attrs ->
		if (!attrs[BEAN_ATTR]) throwTagError("Tag [all] is missing required attribute [$BEAN_ATTR]")
		BeanAndPrefix beanPrefix = resolveBeanAndPrefix(attrs[BEAN_ATTR], attrs.prefix, attrs)
		try {
			beanStack.push(beanPrefix)
			def bean = resolveBean(attrs[BEAN_ATTR])
			def prefix = resolvePrefix(attrs.prefix)
			def domainClass = resolveDomainClass(bean)
			if (domainClass) {
				for (property in resolvePersistentProperties(domainClass, attrs)) {
					out << field([bean: bean, property: property.name, prefix: prefix])
				}
			} else {
				throwTagError('Tag [all] currently only supports domain types')
			}
		} finally {
			beanStack.pop()
		}
	}

	/**
	 * @attr bean Name of the source bean in the GSP model.
	 * @attr property REQUIRED The name of the property to display. This is resolved
	 * against the specified bean or the bean in the current scope.
	 * @attr value Specifies the initial value to display in the field. The default is
	 * the current value of the property.
	 * @attr default A default initial value to display if the actual property value
	 * evaluates to {@code false}.
	 * @attr required Specifies whether the user is required to enter a value for this
	 * property. By default, this is determined by the constraints of the property.
	 * @attr invalid Specifies whether this property is invalid or not. By default, this
	 * is determined by whether there are any errors associated with it.
	 * @attr label Overrides the default label displayed next to the input field.
	 * @attr prefix Prefix to add to input element names.
	 * @attr wrapper Specify the folder inside _fields where to look up for the wrapper template.
	 * @attr widget Specify the folder inside _fields where to look up for the widget template.
	 * @attr templates Specify the folder inside _fields where to look up for the wrapper and widget template.
	 * @attr theme Theme name
	 */
	def field = { attrs, body ->
		attrs = beanStack.innerAttributes + attrs
		if (attrs.containsKey(BEAN_ATTR) && !attrs[BEAN_ATTR]) throwTagError("Tag [field] requires a non-null value for attribute [$BEAN_ATTR]")
		if (!attrs[PROPERTY_ATTR]) throwTagError("Tag [field] is missing required attribute [$PROPERTY_ATTR]")

		def bean = resolveBean(attrs.remove(BEAN_ATTR))
		String property = attrs.remove(PROPERTY_ATTR)
		String templatesFolder = attrs.remove(TEMPLATES_ATTR)
		String fieldFolder = attrs.remove(WRAPPER_ATTR)
		String widgetFolder = attrs.remove(WIDGET_ATTR)
		String theme = attrs.remove(THEME_ATTR)

		BeanPropertyAccessor propertyAccessor = resolveProperty(bean, property)
		if (propertyAccessor.domainProperty instanceof Embedded) {
			renderEmbeddedProperties(bean, propertyAccessor, attrs + [templates: templatesFolder, field: fieldFolder, input: widgetFolder, theme: theme])
		} else {
			Map model = buildModel(propertyAccessor, attrs)
			Map wrapperAttrs = [:]
			Map widgetAttrs = [:]

			String prefixAttribute = formFieldsTemplateService.getWidgetPrefix() ?: 'widget-'
			attrs.each { k, v ->

				if (k?.startsWith(prefixAttribute))
					widgetAttrs[k.replace(prefixAttribute, '')] = v
				else
					wrapperAttrs[k] = v
			}

			if (hasBody(body)) {
				model.widget = raw(body(model + [attrs: widgetAttrs] + widgetAttrs))
			} else {
				model.widget = renderWidget(propertyAccessor, model, widgetAttrs, widgetFolder ?: templatesFolder, theme)
			}


			String templateName = formFieldsTemplateService.getTemplateFor("wrapper")
			Map template = formFieldsTemplateService.findTemplate(propertyAccessor, templateName, fieldFolder ?: templatesFolder, theme)
			if (template) {
				out << render(template: template.path, plugin: template.plugin, model: model + [attrs: wrapperAttrs] + wrapperAttrs)
			} else {
				out << renderDefaultField(model)
			}
		}
	}
	/**
	 * Renders a collection of beans in a table
	 *
	 * @attr collection REQUIRED The collection of beans to render
	 * @attr domainClass The FQN of the domain class of the elements in the collection.
	 * Defaults to the class of the first element in the collection.
	 * @attr properties OPTIONAL The list of properties to be shown (table columns).
	 * @attr maxProperties OPTIONAL The number of properties displayed when no explicit properties are given, defaults to 7.
	 * @attr displayStyle OPTIONAL Determines the display template used for the bean's properties.
	 * Defaults to 'table', meaning that 'display-table' templates will be used when available.
	 * @attr order A comma-separated list of properties to include in provided order
	 * @attr except A comma-separated list of properties to exclude
	 * @attr theme Theme name
	 * @attr template OPTIONAL The template used when rendering the collection
	 */
	def table = { attrs, body ->
		def collection = resolveBean(attrs.remove('collection'))
		PersistentEntity domainClass
		if (attrs.containsKey('domainClass')) {
			domainClass = resolveDomainClass((String) attrs.remove('domainClass'))
		} else {
			domainClass = (collection instanceof Collection) && collection ? resolveDomainClass(collection.iterator().next()) : null
		}

		if (domainClass) {
			List<BeanPropertyAccessor> properties = resolveProperties(domainClass, attrs)

			List<Map> columnProperties = properties.collect { propertyAccessor ->
				buildColumnModel(propertyAccessor, attrs)
			}

			String displayStyle = attrs.remove(DISPLAY_STYLE)
			String theme = attrs.remove(THEME_ATTR)
			String template = attrs.remove('template') ?: 'table'

			out << render(
				template: "/templates/_fields/$template",
				model: attrs + [domainClass: domainClass,
						domainProperties: columnProperties,
						columnProperties: columnProperties,
						collection: collection,
						displayStyle: displayStyle,
						theme: theme])
		}
	}

	/**
	 * @deprecated since version 1.5 - Use widget instead
	 * @attr bean Name of the source bean in the GSP model.
	 * @attr property REQUIRED The name of the property to display. This is resolved
	 * against the specified bean or the bean in the current scope.
	 */
	def input = { attrs ->
		out << widget(attrs)
	}

	/**
	 * @attr bean Name of the source bean in the GSP model.
	 * @attr property REQUIRED The name of the property to display. This is resolved
	 * against the specified bean or the bean in the current scope.
	 * @attr theme Theme name
	 */
	def widget = { attrs ->
		def bean = resolveBean(attrs.remove(BEAN_ATTR))
		if (!bean) throwTagError("Tag [input] is missing required attribute [$BEAN_ATTR]")
		if (!attrs.property) throwTagError("Tag [input] is missing required attribute [property]")

		attrs = getPrefixedAttributes(beanStack.innerAttributes) + attrs

		String property = attrs.remove(PROPERTY_ATTR)
		String widgetFolder = attrs.remove(WIDGET_ATTR)
		String theme = attrs.remove(THEME_ATTR)

		BeanPropertyAccessor propertyAccessor = resolveProperty(bean, property)
		Map model = buildModel(propertyAccessor, attrs)

		out << renderWidget(propertyAccessor, model, attrs, widgetFolder, theme)
	}

	/**
	 * @attr bean Name of the source bean in the GSP model.
	 * @attr property REQUIRED The name of the property to display. This is resolved
	 * against the specified bean or the bean in the current scope.
	 * @attr theme Theme name
	 */
	def displayWidget = { attrs ->
		def bean = resolveBean(attrs.remove(BEAN_ATTR))
		if (!bean) throwTagError("Tag [displayWidget] is missing required attribute [$BEAN_ATTR]")
		if (!attrs[PROPERTY_ATTR]) throwTagError("Tag [displayWidget] is missing required attribute [property]")

		attrs = getPrefixedAttributes(beanStack.innerAttributes) + attrs

		String property = attrs.remove(PROPERTY_ATTR)
		String widgetFolder = attrs.remove(WIDGET_ATTR)
		String theme = attrs.remove(THEME_ATTR)

		BeanPropertyAccessor propertyAccessor = resolveProperty(bean, property)
		Map model = buildModel(propertyAccessor, attrs, 'HTML')

		out << renderDisplayWidget(propertyAccessor, model, attrs, widgetFolder, theme)
	}

	/**
	 * @attr bean Name of the source bean in the GSP model.
	 * @attr property The name of the property to display. This is resolved against the specified bean or the bean in the current scope.
	 * @attr order A comma-separated list of properties to include in provided order
	 * @attr except A comma-separated list of properties to exclude
	 * @attr theme Theme name
	 * @attr template OPTIONAL The template used when rendering the domainClass
	 */
	def display = { attrs, body ->
		attrs = beanStack.innerAttributes + attrs
		def bean = resolveBean(attrs.remove(BEAN_ATTR))
		if (!bean) throwTagError("Tag [display] is missing required attribute [$BEAN_ATTR]")

		String property = attrs.remove(PROPERTY_ATTR)
		String templatesFolder = attrs.remove(TEMPLATES_ATTR)
		String theme = attrs.remove(THEME_ATTR)        

		if (property == null) {
			PersistentEntity domainClass = resolveDomainClass(bean)
			if (domainClass) {
				String template = attrs.remove('template') ?: 'list'

				List properties = resolvePersistentProperties(domainClass, attrs)
				out << render(template: "/templates/_fields/$template", model: [domainClass: domainClass, domainProperties: properties]) { prop ->
					BeanPropertyAccessor propertyAccessor = resolveProperty(bean, prop.name)
					Map model = buildModel(propertyAccessor, attrs, 'HTML')
					out << raw(renderDisplayWidget(propertyAccessor, model, attrs, templatesFolder, theme))
				}
			}
		} else {
			String displayFolder = attrs.remove(WRAPPER_ATTR)
			String widgetFolder = attrs.remove(WIDGET_ATTR)

			BeanPropertyAccessor propertyAccessor = resolveProperty(bean, property)
			Map model = buildModel(propertyAccessor, attrs, 'HTML')

			Map wrapperAttrs = [:]
			Map widgetAttrs = [:]

			String prefixAttribute = formFieldsTemplateService.getWidgetPrefix() ?: 'widget-'
			attrs.each { k, v ->
				if (k?.startsWith(prefixAttribute))
					widgetAttrs[k.replace(prefixAttribute, '')] = v
				else
					wrapperAttrs[k] = v
			}


			String wrapperFolderTouse = displayFolder ?: templatesFolder
			String widgetsFolderToUse = widgetFolder ?: templatesFolder

			if (hasBody(body)) {
				model.widget = raw(body(model + [attrs: widgetAttrs] + widgetAttrs))
				model.value = body(model)
			} else {
				model.widget = renderDisplayWidget(propertyAccessor, model, widgetAttrs, widgetsFolderToUse, theme)
			}


			def displayWrapperTemplateName = formFieldsTemplateService.getTemplateFor("displayWrapper")
			def template = formFieldsTemplateService.findTemplate(propertyAccessor, displayWrapperTemplateName, wrapperFolderTouse, theme)
			if (template) {
				out << render(template: template.path, plugin: template.plugin, model: model + [attrs: wrapperAttrs] + wrapperAttrs)
			} else {
				out << raw(renderDisplayWidget(propertyAccessor, model, attrs, widgetsFolderToUse, theme))
			}
		}

	}

	private Map getPrefixedAttributes(attrs) {
		Map widgetAttrs = [:]
		attrs.each { k, v ->
			String prefixAttribute = formFieldsTemplateService.getWidgetPrefix()
			if (k?.startsWith(prefixAttribute))
				widgetAttrs[k.replace(prefixAttribute, '')] = v
		}
		return widgetAttrs
	}

	private void renderEmbeddedProperties(bean, BeanPropertyAccessor propertyAccessor, attrs) {
		def legend = resolveMessage(propertyAccessor.labelKeys, propertyAccessor.defaultLabel)
		out << applyLayout(name: '_fields/embedded', params: [type: toPropertyNameFormat(propertyAccessor.propertyType), legend: legend]) {
			Embedded prop = (Embedded) propertyAccessor.domainProperty
			for (embeddedProp in resolvePersistentProperties(prop.associatedEntity, attrs)) {
				def propertyPath = "${propertyAccessor.pathFromRoot}.${embeddedProp.name}"
				out << field(bean: bean, property: propertyPath, prefix: attrs.prefix, default: attrs.default, field: attrs.field, widget: attrs.widget, theme: attrs[THEME_ATTR])
			}
		}
	}

	private BeanPropertyAccessor resolveProperty(bean, String propertyPath) {
		beanPropertyAccessorFactory.accessorFor(bean, propertyPath)
	}

	private List<BeanPropertyAccessor> resolveProperties(PersistentEntity domainClass, Map attrs) {
		// Starting point for the bean property resolver
		def bean = domainClass.javaClass.newInstance()

		List<BeanPropertyAccessor> propertyAccessorList = resolvePropertyNames(domainClass, attrs).collect { String propertyPath ->
			beanPropertyAccessorFactory.accessorFor(bean, propertyPath)
		}

		return propertyAccessorList

	}

	private List<String> resolvePropertyNames(PersistentEntity domainClass, Map attrs) {
		if (attrs.containsKey('order')) {
			return getList(attrs.order)
		}
		else if (attrs.containsKey('properties')) {
			return getList(attrs.remove('properties'))
		} else {

			List<String> properties = resolvePersistentProperties(domainClass, attrs, true)*.name
			int maxProperties = attrs.containsKey('maxProperties') ? attrs.remove('maxProperties').toInteger() : 7
			if (maxProperties && properties.size() > maxProperties) {
				properties = properties[0..<maxProperties]
			}
			return properties
		}
	}

	private Map buildColumnModel(BeanPropertyAccessor propertyAccessor, Map attrs) {
		def labelText = resolveLabelText(propertyAccessor, attrs)
		return [
			bean              : propertyAccessor.rootBean,
			name              : propertyAccessor.pathFromRoot, // To please legacy _table.gsp
			property          : propertyAccessor.pathFromRoot,
			type              : propertyAccessor.propertyType,
			defaultLabel      : labelText, // To please legacy _table.gsp
			label             : labelText,
			constraints       : propertyAccessor.constraints,
			required          : propertyAccessor.required,
		]
	}


	private Map buildModel(BeanPropertyAccessor propertyAccessor, Map attrs, String encoding = null) {
		def value = attrs.containsKey('value') ? attrs.remove('value') : propertyAccessor.value
		def valueDefault = attrs.remove('default')
		if (value instanceof String && encoding) {
			value = codecLookup.lookupEncoder(encoding).encode(value)
		}

		[
			bean              : propertyAccessor.rootBean,
			property          : propertyAccessor.pathFromRoot,
			type              : propertyAccessor.propertyType,
			beanClass         : propertyAccessor.entity,
			label             : resolveLabelText(propertyAccessor, attrs),
			value             : (value instanceof Number || value instanceof Boolean || value) ? value : valueDefault,
			constraints       : propertyAccessor.constraints,
			persistentProperty: propertyAccessor.domainProperty,
			errors            : propertyAccessor.errors.collect { error ->
				String errorMsg = null
				try {
					errorMsg = error instanceof MessageSourceResolvable ? messageSource.getMessage(error, locale) : messageSource.getMessage(error.toString(), null, locale)
				}
				catch (NoSuchMessageException ignored) {
					// no-op
				}
				// unresolved message codes fallback to the defaultMessage and this should
				// be escaped as it could be an error message with user input
				errorMsg && errorMsg == error.defaultMessage ? message(error: error, encodeAs: "HTML") :  message(error: error)
			},
			required          : attrs.containsKey("required") ? Boolean.valueOf(attrs.remove('required')) : propertyAccessor.required,
			invalid           : attrs.containsKey("invalid") ? Boolean.valueOf(attrs.remove('invalid')) : propertyAccessor.invalid,
			prefix            : resolvePrefix(attrs.remove('prefix')),
		]
	}

	private CharSequence renderWidget(BeanPropertyAccessor propertyAccessor, Map model, Map attrs = [:], String widgetFolder, String theme) {
		String widgetTemplateName = formFieldsTemplateService.getTemplateFor("widget")
		Map template = formFieldsTemplateService.findTemplate(propertyAccessor, widgetTemplateName, widgetFolder, theme)
		if (template) {
			render template: template.path, plugin: template.plugin, model: model + [attrs: attrs] + attrs
		} else {
			renderDefaultInput propertyAccessor, model, attrs
		}
	}

	private CharSequence renderDisplayWidget(BeanPropertyAccessor propertyAccessor, Map model, Map attrs = [:], String widgetFolder, String theme) {
		String displayStyle = attrs.displayStyle

		Map template = null
		if (displayStyle && displayStyle != 'default') {
			template = formFieldsTemplateService.findTemplate(propertyAccessor, "displayWidget-$attrs.displayStyle", widgetFolder, theme)
		}
		if (!template) {
			def displayWidgetTemplateName = formFieldsTemplateService.getTemplateFor("displayWidget")
			template = formFieldsTemplateService.findTemplate(propertyAccessor, displayWidgetTemplateName, widgetFolder, theme)
		}

		if (template) {
			render template: template.path, plugin: template.plugin, model: model + [attrs: attrs] + attrs
		} else if (!(model.value instanceof CharSequence)) {
			renderDefaultDisplay(model, attrs, widgetFolder, theme)
		} else {
			model.value
		}
	}

	private resolvePageScopeVariable(attributeName) {
		// Tomcat throws NPE if you query pageScope for null/empty values
		attributeName?.toString() ? pageScope.variables[attributeName] : null
	}

	private BeanAndPrefix resolveBeanAndPrefix(beanAttribute, prefixAttribute, attributes) {
		def bean = resolvePageScopeVariable(beanAttribute) ?: beanAttribute
		def prefix = resolvePageScopeVariable(prefixAttribute) ?: prefixAttribute
		def innerAttributes = attributes.clone()
		innerAttributes.remove('bean')
		innerAttributes.remove('prefix')
		//'except' is a reserved word for the 'all' tag: https://github.com/grails-fields-plugin/grails-fields/issues/12
		innerAttributes.remove('except')
		new BeanAndPrefix(bean: bean, prefix: prefix, innerAttributes: innerAttributes)
	}

	private Object resolveBean(beanAttribute) {
		resolvePageScopeVariable(beanAttribute) ?: beanAttribute ?: beanStack.bean
	}

	private String resolvePrefix(prefixAttribute) {
		def prefix = resolvePageScopeVariable(prefixAttribute) ?: prefixAttribute ?: beanStack.prefix
		if (prefix && !prefix.endsWith('.'))
			prefix = prefix + '.'
		prefix ?: ''
	}

	private PersistentEntity resolveDomainClass(bean) {
		resolveDomainClass(bean.getClass())
	}

	private PersistentEntity resolveDomainClass(Class beanClass) {
		resolveDomainClass(beanClass.name)
	}

	private PersistentEntity resolveDomainClass(String beanClassName) {
		mappingContexts.findResult { MappingContext mappingContext ->
			mappingContext.getPersistentEntity(beanClassName)
		}
	}

	private List<PersistentProperty> resolvePersistentProperties(PersistentEntity domainClass, Map attrs, boolean list = false) {
		List<PersistentProperty> properties

		if (attrs.order) {
			if (attrs.except) {
				throwTagError('The [except] and [order] attributes may not be used together.')
			}
			def orderBy = getList(attrs.order)
			properties = orderBy.collect { propertyName ->
				fieldsDomainPropertyFactory.build(domainClass.getPropertyByName(propertyName))
			}
		} else {
			properties = list ? domainModelService.getListOutputProperties(domainClass) : domainModelService.getInputProperties(domainClass)
			// If 'except' is not set, but 'list' is, exclude 'id', 'dateCreated' and 'lastUpdated' by default
			List<String> blacklist = attrs.containsKey('except') ? getList(attrs.except) : (list ? ['id', 'dateCreated', 'lastUpdated'] : [])

			properties.removeAll { it.name in blacklist }
		}

		return properties
	}

	private static List<String> getList(def except, List<String> defaultList = []) {
		if (!except) {
			return defaultList
		} else if (except instanceof String) {
			except?.tokenize(',')*.trim()
		} else if (except instanceof Collection) {
			return except as List<String>
		} else {
			throw new IllegalArgumentException("Must either be null, comma separated string or java.util.Collection")
		}
	}

	private boolean hasBody(Closure body) {
		return body && !body.is(GroovyPage.EMPTY_BODY_CLOSURE)
	}

	private CharSequence resolveLabelText(BeanPropertyAccessor propertyAccessor, Map attrs) {
		def labelText
		def label = attrs.remove('label')
		if (label) {
			labelText = message(code: label, default: label)
		}
		if (!labelText && propertyAccessor.labelKeys) {
			labelText = resolveMessage(propertyAccessor.labelKeys, propertyAccessor.defaultLabel)
		}
		if (!labelText) {
			labelText = propertyAccessor.defaultLabel
		}
		return labelText
	}

	private CharSequence resolveMessage(List<String> keysInPreferenceOrder, String defaultMessage) {
		def message = keysInPreferenceOrder.findResult { key ->
			message(code: key, default: null) ?: null
		}
		if(log.traceEnabled && !message) {
			log.trace("i18n missing translation for one of ${keysInPreferenceOrder}")
		}
		message ?: defaultMessage
	}

	private CharSequence renderDefaultField(Map model) {
		List classes = ['fieldcontain']
		if (model.invalid) classes << 'error'
		if (model.required) classes << 'required'

		Writer writer = new FastStringWriter()
		new MarkupBuilder(writer).div(class: classes.join(' ')) {
			label(for: (model.prefix ?: '') + model.property, model.label) {
				if (model.required) {
					span(class: 'required-indicator', '*')
				}
			}
			// TODO: encoding information of widget gets lost - don't use MarkupBuilder
			def widget = model.widget
			if (widget != null) {
				mkp.yieldUnescaped widget
			}

		}
		writer.buffer
	}

	CharSequence renderDefaultInput(Map model, Map attrs = [:]) {
		renderDefaultInput(null, model, attrs)
	}

	CharSequence renderDefaultInput(BeanPropertyAccessor propertyAccessor, Map model, Map attrs = [:]) {
		Constrained constrained = (Constrained) model.constraints
		attrs.name = (model.prefix ?: '') + model.property
		attrs.value = model.value
		if (model.required) attrs.required = "" // TODO: configurable how this gets output? Some people prefer required="required"
		if (model.invalid) attrs.invalid = ""
		if (!isEditable(constrained)) attrs.readonly = ""

		boolean oneToOne = false
		boolean manyToOne = false
		boolean manyToMany = false
		boolean oneToMany = false
		if (model.containsKey('persistentProperty')) {
			if (model.persistentProperty instanceof PersistentProperty) {
				PersistentProperty prop = (PersistentProperty) model.persistentProperty
				oneToOne = prop instanceof OneToOne
				manyToOne = prop instanceof ManyToOne
				manyToMany = prop instanceof ManyToMany
				oneToMany = prop instanceof OneToMany
			}
		}

		if (model.type in [String, null]) {
			return renderStringInput(model, attrs)
		} else if (model.type in [boolean, Boolean]) {
			return g.checkBox(attrs)
		} else if (model.type.isPrimitive() || model.type in Number) {
			return renderNumericInput(propertyAccessor, model, attrs)
		} else if (model.type in URL) {
			return g.field(attrs + [type: "url"])
		} else if (model.type.isEnum()) {
			return renderEnumInput(model, attrs)
		} else if (oneToOne || manyToOne || manyToMany) {
			return renderAssociationInput(model, attrs)
		} else if (oneToMany) {
			return renderOneToManyInput(model, attrs)
		} else if (model.type in [Date, Calendar, java.sql.Date, java.sql.Time]) {
			return renderDateTimeInput(model, attrs)
		} else if (model.type in [byte[], Byte[], Blob]) {
			return g.field(attrs + [type: "file"])
		} else if (model.type in [TimeZone, Currency, Locale]) {
			if (!model.required) attrs.noSelection = ["": ""]
			return g."${StringUtils.uncapitalize(model.type.simpleName)}Select"(attrs)
		} else {
			return null
		}
	}


	CharSequence renderDateTimeInput(Map model, Map attrs) {
		attrs.precision = model.type == java.sql.Time ? "minute" : "day"
		if (!model.required) {
			attrs.noSelection = ["": ""]
			attrs.default = "none"
		}
		return g.datePicker(attrs)
	}

	CharSequence renderStringInput(Map model, Map attrs) {
		Constrained constrained = (Constrained) model.constraints

		if (!attrs.type) {
			if (constrained?.inList) {
				attrs.from = constrained.inList
				if (!model.required) attrs.noSelection = ["": ""]
				return g.select(attrs)
			} else if (constrained?.password) {
				attrs.type = "password"
				attrs.remove('value')
			} else if (constrained?.email) attrs.type = "email"
			else if (constrained?.url) attrs.type = "url"
			else attrs.type = "text"
		}

		if (constrained?.matches) attrs.pattern = constrained.matches
		if (constrained?.maxSize) attrs.maxlength = constrained.maxSize

		if (constrained?.widget == 'textarea') {
			attrs.remove('type')
			return g.textArea(attrs)
		}
		return g.field(attrs)
	}

	CharSequence renderNumericInput(BeanPropertyAccessor propertyAccessor, Map model, Map attrs) {
		Constrained constrained = (Constrained) model.constraints

		if (!attrs.type && constrained?.inList) {
			attrs.from = constrained.inList
			if (!model.required) attrs.noSelection = ["": ""]
			return g.select(attrs)
		} else if (constrained?.range) {
			attrs.type = attrs.type ?: "range"
			attrs.min = constrained.range.from
			attrs.max = constrained.range.to
		} else {
			attrs.type = attrs.type ?: getDefaultNumberType(model)
			if (constrained?.scale != null) attrs.step = "0.${'0' * (constrained.scale - 1)}1"
			if (constrained?.min != null) attrs.min = constrained.min
			if (constrained?.max != null) attrs.max = constrained.max
		}

		if (localizeNumbers && propertyAccessor?.value != null) {
			attrs.value = numberFormatter.format(propertyAccessor.value)
		}

		return g.field(attrs)
	}

	@CompileStatic
	protected NumberFormat getNumberFormatter() {
		NumberFormat.getInstance(getLocale())
	}

	@CompileStatic
	protected Locale getLocale() {
		def locale
		def request = GrailsWebRequest.lookup()?.currentRequest
		if (request instanceof HttpServletRequest) {
			locale = localeResolver?.resolveLocale(request)
		}
		if (locale == null) {
			locale = Locale.default
		}
		return locale
	}

	@CompileStatic
	protected String getDefaultNumberType(Map model) {
		Class modelType = (Class) model.type

		def typeName = modelType.simpleName.toLowerCase()
		if (typeName in DECIMAL_TYPES) {
			return "number decimal"
		} else {
			return "number"
		}

	}

	private CharSequence renderEnumInput(Map model, Map attrs) {
		Constrained constrained = (Constrained) model.constraints

		if (attrs.value instanceof Enum)
			attrs.value = attrs.value.name()
		if (!model.required) attrs.noSelection = ["": ""]

		if (constrained?.inList) {
			attrs.keys = constrained.inList*.name()
			attrs.from = constrained.inList
		} else {
			attrs.keys = model.type.values()*.name()
			attrs.from = model.type.values()
		}
		return g.select(attrs)
	}

	private CharSequence renderAssociationInput(Map model, Map attrs) {
		attrs.id = (model.prefix ?: '') + model.property
		def persistentProperty = model.persistentProperty
		Class referencedPropertyType
		boolean manyToMany = false
		if (persistentProperty instanceof Association) {
			Association prop = ((Association) persistentProperty)
			PersistentEntity entity = prop.getAssociatedEntity()
			if (entity != null) {
				referencedPropertyType = entity.getJavaClass()
			} else if (prop.isBasic()) {
				referencedPropertyType = ((Basic) prop).getComponentType()
			}
			manyToMany = prop instanceof ManyToMany
		}
		attrs.from = null != attrs.from ? attrs.from : referencedPropertyType.list()
		attrs.optionKey = "id" // TODO: handle alternate id names
		if (manyToMany) {
			attrs.multiple = ""
			attrs.value = model.value*.id
			attrs.name = "${model.prefix ?: ''}${model.property}"
		} else {
			if (!model.required) attrs.noSelection = ["null": ""]
			attrs.value = model.value?.id
			attrs.name = "${model.prefix ?: ''}${model.property}.id"
		}
		return g.select(attrs)
	}

	private CharSequence renderOneToManyInput(Map model, Map attrs) {
		Writer buffer = new FastStringWriter()
		buffer << '<ul>'
		def persistentProperty = model.persistentProperty
		def controllerName
		def shortName
		if (persistentProperty instanceof Association) {
			Association prop = ((Association) persistentProperty)
			controllerName = prop.associatedEntity.decapitalizedName
			shortName = prop.associatedEntity.javaClass.simpleName
		}

		attrs.value.each {
			buffer << '<li>'
			buffer << g.link(controller: controllerName, action: "show", id: it.id, it.toString().encodeAsHTML())
			buffer << '</li>'
		}
		buffer << '</ul>'
		def referencedTypeLabel = message(code: "${controllerName}.label", default: shortName)
		def addLabel = g.message(code: 'default.add.label', args: [referencedTypeLabel])
		PersistentEntity beanClass = (PersistentEntity) model.beanClass
		buffer << g.link(controller: controllerName, action: "create", params: [("${beanClass.decapitalizedName}.id".toString()): model.bean.id], addLabel)
		buffer.buffer
	}

	private CharSequence renderDefaultDisplay(Map model, Map attrs = [:], String templatesFolder, String theme) {
		def persistentProperty = model.persistentProperty
		if (persistentProperty instanceof Association) {
			if (persistentProperty.embedded) {
				return (attrs.displayStyle == 'table') ? model.value?.toString().encodeAsHTML() :
					displayEmbedded(model.value, persistentProperty.associatedEntity, attrs, templatesFolder, theme)
			} else if (persistentProperty instanceof OneToMany || persistentProperty instanceof ManyToMany) {
				return displayAssociationList(model.value, ((Association) persistentProperty).associatedEntity)
			} else {
				return displayAssociation(model.value, ((Association) persistentProperty).associatedEntity)
			}
		}

		switch (model.type) {
			case Boolean.TYPE:
			case Boolean:
				g.formatBoolean(boolean: model.value)
				break
			case Calendar:
			case Date:
			case java.sql.Date:
			case java.sql.Time:
				g.formatDate(date: model.value)
				break
			default:
				g.fieldValue bean: model.bean, field: model.property
		}
	}

	private CharSequence displayEmbedded(bean, PersistentEntity domainClass, Map attrs, String templatesFolder, String theme) {
		Writer buffer = new FastStringWriter()
		def properties = domainModelService.getOutputProperties(domainClass)
		buffer << render(template: "/templates/_fields/list", model: [domainClass: domainClass, domainProperties: properties]) { prop ->
			def propertyAccessor = resolveProperty(bean, prop.name)
			def model = buildModel(propertyAccessor, attrs)
			out << raw(renderDisplayWidget(propertyAccessor, model, attrs, templatesFolder, theme))
		}
		buffer.buffer
	}

	private CharSequence displayAssociationList(values, PersistentEntity referencedDomainClass) {
		Writer buffer = new FastStringWriter()
		buffer << '<ul>'
		for (value in values) {
			buffer << '<li>'
			buffer << displayAssociation(value, referencedDomainClass)
			buffer << '</li>'
		}
		buffer << '</ul>'
		buffer.buffer
	}

	private CharSequence displayAssociation(value, PersistentEntity referencedDomainClass) {
		if (value && referencedDomainClass) {
			g.link(controller: referencedDomainClass.decapitalizedName, action: "show", id: value.id, value.toString().encodeAsHTML())
		} else if (value) {
			value.toString()
		}
	}

	private boolean isEditable(Constrained constraints) {
		!constraints || constraints.editable
    }

}