autoform-events.js

/* global AutoForm, arrayTracker $ */
import { Template } from 'meteor/templating'
import { isObject, throttle } from './common'
import {
  updateTrackedFieldValue,
  updateAllTrackedFieldValues
} from './autoform-inputs'
import { validateField } from './autoform-validation'
import { Hooks } from './autoform-hooks'
import { Utility } from './utility'

// all form events handled here
let lastAutoSaveElement = null
const lastKeyVals = {}

function beginSubmit (formId, template, hookContext) {
  if (!Utility.checkTemplate(template)) return

  // Get user-defined hooks
  const hooks = Hooks.getHooks(formId, 'beginSubmit')
  if (hooks.length) {
    hooks.forEach(function beginSubmitHooks (hook) {
      hook.call(hookContext)
    })
  }
  else {
    // If there are no user-defined hooks, by default we disable the submit button during submission
    const submitButton =
      template.find('button[type=submit]') ||
      template.find('input[type=submit]')
    if (submitButton) {
      submitButton.disabled = true
    }
  }
}

function endSubmit (formId, template, hookContext) {
  if (!Utility.checkTemplate(template)) return

  // Try to avoid incorrect reporting of which input caused autosave
  lastAutoSaveElement = null
  // Get user-defined hooks
  const hooks = Hooks.getHooks(formId, 'endSubmit')
  if (hooks.length) {
    hooks.forEach(function endSubmitHooks (hook) {
      hook.call(hookContext)
    })
  }
  else {
    // If there are no user-defined hooks, by default we disable the submit button during submission
    const submitButton =
      template.find('button[type=submit]') ||
      template.find('input[type=submit]')
    if (submitButton) {
      submitButton.disabled = false
    }
  }
}

function adjustKeyForArrays (key) {
  const gKey = AutoForm.Utility.makeKeyGeneric(key)
  if (gKey.slice(-2) === '.$' || gKey.indexOf('.$.') !== -1) {
    key = gKey.slice(0, gKey.indexOf('.$'))
  }
  return key
}

/**
 * Returns `true` if the specified validation type should
 * be revalidated only when the form is already invalid.
 * @param {String} validationType The validation type string.
 */
function onlyIfAlreadyInvalid (validationType) {
  return (
    validationType === 'submitThenKeyup' || validationType === 'submitThenBlur'
  )
}

/**
 * Given an element, returns the schema key for it, using the
 * `data-schema-key` attribute on the element or on the closest
 * element that has one.
 *
 * @param   {Element}          element The DOM element
 * @returns {String|undefined} The schema key
 */
function getKeyForElement (element) {
  let key = element.getAttribute('data-schema-key')
  if (!key) {
    key = $(element).closest('[data-schema-key]').attr('data-schema-key')
  }
  return key
}

// throttle autosave, at most autosave every 500ms
const throttleAutosave = throttle(function (event) {
  lastAutoSaveElement = event.target
  $(event.currentTarget).submit()
}, 500)

Template.autoForm.events({
  'submit form': function autoFormSubmitHandler (event, template) {
    let formDoc
    // Gather necessary form info
    const formId = this.id
    const form = AutoForm.getCurrentDataForForm(formId)
    const formType = form.type
    // ss will be the schema for the `schema` attribute if present,
    // else the schema for the collection
    const ss = AutoForm.getFormSchema(formId)
    const collection = AutoForm.getFormCollection(formId)
    const ssIsOverride = !!(collection && form.schema)

    const currentDoc = form.doc
    const docId = currentDoc ? currentDoc._id : null
    let isValid

    const validationOptions = {
      validationContext: formId,
      filter: form.filter,
      autoConvert: form.autoConvert,
      removeEmptyStrings: form.removeEmptyStrings,
      trimStrings: form.trimStrings
    }

    // Get the form type definition
    let ftd
    try {
      ftd = Utility.getFormTypeDef(formType)
    }
    catch (err) {
      event.preventDefault()
      throw err
    }

    // Gather hooks
    const onSuccessHooks = Hooks.getHooks(formId, 'onSuccess')
    const onErrorHooks = Hooks.getHooks(formId, 'onError')
    const beforeHooks = Hooks.getHooks(formId, 'before', formType)
    const afterHooks = Hooks.getHooks(formId, 'after', formType)

    // Prep context with which hooks are called
    const hookContext = {
      addStickyValidationError: function (key, type, value) {
        AutoForm.addStickyValidationError(formId, key, type, value)
      },
      autoSaveChangedElement: lastAutoSaveElement,
      collection: collection,
      currentDoc: currentDoc,
      docId: docId,
      event: event,
      formAttributes: form,
      formId: formId,
      formTypeDefinition: ftd,
      removeStickyValidationError: function (key) {
        AutoForm.removeStickyValidationError(formId, key)
      },
      resetForm: function () {
        AutoForm.resetForm(formId, template)
      },
      ss: ss,
      ssIsOverride: ssIsOverride,
      template: template,
      validationContext: AutoForm.getValidationContext(formId)
    }

    // Gather all form values
    if (ftd.needsModifierAndDoc) {
      formDoc = AutoForm.getFormValues(formId, template, ss)
      hookContext.updateDoc = formDoc.updateDoc
      hookContext.insertDoc = formDoc.insertDoc
    }
    else if (ftd.usesModifier) {
      formDoc = AutoForm.getFormValues(formId, template, ss, true)
      hookContext.updateDoc = formDoc
    }
    else {
      formDoc = AutoForm.getFormValues(formId, template, ss, false)
      hookContext.insertDoc = formDoc
    }

    // It is pretty unlikely since we are submitting it, but if
    // for some reason this form is not currently rendered, we exit.
    if (!formDoc) {
      event.preventDefault()
      return
    }

    function endSubmission () {
      // Run endSubmit hooks (re-enabled submit button or form, etc.)
      endSubmit(formId, template, hookContext)
    }

    function failedValidation () {
      // add validationErrors array as a property
      // of the Error object before we call
      // onError hooks
      const ec = ss.namedContext(formId)
      const ik = ec.validationErrors()
      let error
      if (ik) {
        if (ik.length) {
          error = new Error(ik[0].message || ec.keyErrorMessage(ik[0].name))
        }
        else {
          error = new Error('form failed validation')
        }
        error.validationErrors = ik
      }
      else {
        error = new Error('form failed validation')
      }
      onErrorHooks.forEach(function onErrorEach (hook) {
        hook.call(hookContext, 'pre-submit validation', error)
      })
      event.preventDefault()
      event.stopPropagation()
      endSubmission()
    }

    // Prep function that calls before hooks.
    function runBeforeHooks (doc, next) {
      // We call the hooks recursively, in order added,
      // passing the result of the first hook to the
      // second hook, etc.
      function runHook (i, doc) {
        const hook = beforeHooks[i]

        if (!hook) {
          // We've run all hooks; continue submission
          next(doc)
          return
        }

        // Define a `result` function
        const cb = function (d) {
          // If the hook returns false, we cancel
          if (d === false) {
            endSubmission()
          }
          else if (!isObject(d)) {
            throw new Error("A 'before' hook must return an object")
          }
          else {
            runHook(i + 1, d)
          }
        }

        const cbOnce = () => {
          let alreadyRan = false
          return (d) => {
            if (alreadyRan) return
            alreadyRan = true
            return cb(d)
          }
        }

        // Add the `result` function to the before hook context
        const ctx = { result: cbOnce(), ...hookContext }

        const result = hook.call(ctx, doc)

        // If the hook returns undefined, we wait for it
        // to call this.result()
        if (result !== undefined) {
          ctx.result(result)
        }
      }

      runHook(0, doc)
    }

    // Prep function that calls after, onError, and onSuccess hooks.
    // Also resets the form on success.
    function resultCallback (error, result) {
      if (error) {
        if (onErrorHooks && onErrorHooks.length) {
          onErrorHooks.forEach(function onErrorEach (hook) {
            hook.call(hookContext, formType, error)
          })
        }
        else if (
          (!afterHooks || !afterHooks.length) &&
          ss.namedContext(formId).isValid()
        ) {
          // if there are no onError or "after" hooks or validation errors, log the error
          // because it must be some other error from the server
          console.log(error)
        }
      }
      else {
        // By default, we reset form after successful submit, but
        // you can opt out. We should never reset after submit
        // when autosaving.
        if (form.resetOnSuccess !== false && form.autosave !== true) {
          AutoForm.resetForm(formId, template)
        }
        // Set docId in the context for insert forms, too
        if (formType === 'insert') {
          hookContext.docId = result
        }
        onSuccessHooks.forEach(function onSuccessEach (hook) {
          hook.call(hookContext, formType, result)
        })
      }
      afterHooks.forEach(function afterHooksEach (hook) {
        hook.call(hookContext, error, result)
      })
      endSubmission()
    }

    // Run beginSubmit hooks (disable submit button or form, etc.)
    // NOTE: This needs to stay after getFormValues in case a
    // beginSubmit hook disables inputs. We don't get values for
    // disabled inputs, but if they are just disabling during submission,
    // then we actually do want the values.
    //
    // Also keep this before prevalidation so that sticky errors can be
    // removed in this hook.
    beginSubmit(formId, template, hookContext)

    // Ask form type definition whether we should prevalidate. By default we do.
    const shouldPrevalidate = ftd.shouldPrevalidate
      ? ftd.shouldPrevalidate.call(hookContext)
      : true

    if (shouldPrevalidate) {
      // This validation pass happens before any "before" hooks run. We
      // validate against the form schema. Then before hooks can add any missing
      // properties before we validate against the full collection schema.
      try {
        isValid =
          form.validation === 'none' ||
          ftd.validateForm.call({
            form: form,
            formDoc: formDoc,
            useCollectionSchema: false
          })
      }
      catch (e) {
        // Catch exceptions in validation functions which will bubble up here, cause a form with
        // onSubmit() to submit prematurely and prevent the error from being reported
        // (due to a page refresh).
        console.error('Validation error', e)
        isValid = false
      }
      // If we failed pre-submit validation, we stop submission.
      if (isValid === false) {
        failedValidation()
        return
      }
    }

    // Call onSubmit from the form type definition
    ftd.onSubmit.call({
      runBeforeHooks: runBeforeHooks,
      result: resultCallback,
      endSubmission: endSubmission,
      failedValidation: failedValidation,
      validationOptions: validationOptions,
      hookContext: hookContext,
      ...hookContext
    })
  },
  'keyup [data-schema-key]': function autoFormKeyUpHandler (event) {
    // Ignore enter/return, shift, ctrl, cmd, tab, arrows, etc.
    // Most of these are just optimizations, but without ignoring Enter, errors can fail to show up
    // because of conflicts between running onSubmit handlers and this around the same time.
    if ([13, 9, 16, 20, 17, 91, 37, 38, 39, 40].includes(event.keyCode)) return

    // validateField is throttled, so we need to get the nearest form's
    // ID here, while we're still in the correct context
    const formId = AutoForm.getFormId()

    // Get current form data context
    const form = AutoForm.getCurrentDataForForm(formId)

    const validationType = form.validation
    const skipEmpty = !(event.keyCode === 8 || event.keyCode === 46) // if deleting or backspacing, don't skip empty

    if (validationType === 'keyup' || validationType === 'submitThenKeyup') {
      const key = getKeyForElement(event.currentTarget)
      if (!key) return

      validateField(
        key,
        formId,
        skipEmpty,
        onlyIfAlreadyInvalid(validationType)
      )

      // If it's an array field, we also want to validate the entire topmost array
      // in case there are minCount/maxCount errors, etc.
      const arrayKey = adjustKeyForArrays(key)
      if (arrayKey !== key) {
        validateField(
          arrayKey,
          formId,
          skipEmpty,
          onlyIfAlreadyInvalid(validationType)
        )
      }

      // If the form should be auto-saved whenever updated, we do that on field
      // changes instead of validating the field
      if (form.autosaveOnKeyup === true) {
        throttleAutosave(event)
      }
    }
  },
  'blur [data-schema-key]': function autoFormBlurHandler (event) {
    // validateField is throttled, so we need to get the nearest form's
    // ID here, while we're still in the correct context
    const formId = AutoForm.getFormId()

    // Get current form data context
    const form = AutoForm.getCurrentDataForForm(formId)
    const validationType = form.validation

    if (
      validationType === 'keyup' ||
      validationType === 'blur' ||
      validationType === 'submitThenKeyup' ||
      validationType === 'submitThenBlur'
    ) {
      const key = getKeyForElement(event.currentTarget)
      if (!key) {
        return
      }

      validateField(key, formId, false, onlyIfAlreadyInvalid(validationType))

      // If it's an array field, we also want to validate the entire topmost array
      // in case there are minCount/maxCount errors, etc.
      const arrayKey = adjustKeyForArrays(key)
      if (arrayKey !== key) {
        validateField(
          arrayKey,
          formId,
          false,
          onlyIfAlreadyInvalid(validationType)
        )
      }
    }
  },
  'change form': function autoFormChangeHandler (event, template) {
    const key = getKeyForElement(event.target)
    if (!key) {
      return
    }

    const formId = event.target.closest('form').id
    if (formId !== this.id) return

    // Some plugins, like jquery.inputmask, can cause infinite
    // loops by continually saying the field changed when it did not,
    // especially in an autosave situation. This is an attempt to
    // prevent that from happening.
    const $target = $(event.target)
    let keyVal = $target.val()
    if (event.target.type === 'checkbox') {
      // Special handling for checkboxes, which always have the same value
      keyVal = `${keyVal}_${$target.prop('checked')}`
    }

    keyVal = `${key}___${keyVal}`

    if (formId in lastKeyVals && keyVal === lastKeyVals[formId]) {
      return
    }
    lastKeyVals[formId] = keyVal

    const value =
      event.target.type === 'checkbox'
        ? $target.prop('checked')
        : $target.val()

    // Mark field value as changed for reactive updates
    updateTrackedFieldValue(template, key, value)

    // Get current form data context
    const form = AutoForm.getCurrentDataForForm(formId)

    // If the form should be auto-saved whenever updated, we do that on field
    // changes instead of validating the field
    if (form.autosave === true || form.autosaveOnKeyup === true) {
      lastAutoSaveElement = event.target
      $(event.currentTarget).submit()
      return
    }

    const validationType = form.validation

    if (
      validationType === 'keyup' ||
      validationType === 'blur' ||
      validationType === 'submitThenKeyup' ||
      validationType === 'submitThenBlur'
    ) {
      validateField(key, formId, false, onlyIfAlreadyInvalid(validationType))

      // If it's an array field, we also want to validate the entire topmost array
      // in case there are minCount/maxCount errors, etc.
      const arrayKey = adjustKeyForArrays(key)
      if (arrayKey !== key) {
        validateField(
          arrayKey,
          formId,
          false,
          onlyIfAlreadyInvalid(validationType)
        )
      }
    }
  },
  'reset form': function autoFormResetHandler (event, template) {
    const formId = this.id

    AutoForm.formPreserve.clearDocument(formId)

    // Reset array counts
    arrayTracker.resetForm(formId)

    const vc = AutoForm.getValidationContext(formId)
    if (vc) vc.reset()

    event.preventDefault()
    AutoForm._forceResetFormValues(formId)

    // Mark all fields as changed
    updateAllTrackedFieldValues(template)
    // Focus the autofocus element
    template.$('[autofocus]').focus()
  },
  'keydown .autoform-array-item input': function (event) {
    // When enter is pressed in an array item field, default behavior
    // seems to be to "click" the remove item button. This doesn't make
    // sense so we stop it.
    if (event.keyCode === 13) {
      event.preventDefault()
    }
  },
  'click .autoform-remove-item': function autoFormClickRemoveItem (
    event,
    template
  ) {
    const self = this // This type of button must be used within an afEachArrayItem block, so we know the context

    event.preventDefault()

    const name = self.arrayFieldName
    const minCount = self.minCount // optional, overrides schema
    const maxCount = self.maxCount // optional, overrides schema
    const index = self.index
    const data = template.data
    const formId = data && data.id
    const ss = AutoForm.getFormSchema(formId)

    // remove the item we clicked
    arrayTracker.removeFromFieldAtIndex(
      formId,
      name,
      index,
      ss,
      minCount,
      maxCount
    )
  },
  'click .autoform-add-item': function autoFormClickAddItem (event, template) {
    event.preventDefault()

    // We pull from data attributes because the button could be manually
    // added anywhere, so we don't know the data context.
    const btn = $(event.currentTarget)
    const name = btn.attr('data-autoform-field')
    const minCount = btn.attr('data-autoform-minCount') // optional, overrides schema
    const maxCount = btn.attr('data-autoform-maxCount') // optional, overrides schema

    const data = template.data
    const formId = data && data.id
    const ss = AutoForm.getFormSchema(formId)

    arrayTracker.addOneToField(formId, name, ss, minCount, maxCount)
  }
})