git.iko.soy/bridge
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bridge/src/indigo-react/lib/useForm.js
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1import { useCallback, useMemo, useState } from 'react';
2import { keyBy, get, every, some } from 'lodash';
4import { compose } from 'lib/lib';
5import { kDefaultValidator } from 'lib/validators';
6import useSetState from 'lib/useSetState';
8// interface InputConfig {
9// name: string;
10// validators: Function[];
11// transformers: Function[];
12// initialValue: string;
13// autoFocus: boolean;
14// disabled: boolean;
15// ...extra,
16// }
18const defaultsFor = (configs, mapper) =>
19 configs.reduce(
20 (memo, config) => ({ ...memo, [config.name]: mapper(config) }),
21 {}
22 );
24/**
25 * useForm manages a set of inputs for rendering them in a loop
26 */
27export default function useForm(configs = []) {
28 const byName = useMemo(() => keyBy(configs, 'name'), [configs]);
30 // track values
31 const [values, _setValues] = useState(() =>
32 defaultsFor(configs, config => config.initialValue)
33 );
34 const setValue = useCallback(
35 (name, value) => _setValues(values => ({ ...values, [name]: value })),
36 [_setValues]
37 );
38 // ^ NB(shrugs): because we're not syncing the initialValue of _additional_
39 // configs that are added, we won't be able to set an initialValue for a
40 // dynamic form that then triggers validation. for initial configs,
41 // initialValue can be a validated string and everything will be happy,
42 // but for dynamically added input configs, we won't get validation, etc
43 // until there's a traditional state update.
45 // track focused states
46 const [focused, setFocused] = useSetState(() =>
47 defaultsFor(configs, config => config.autoFocus && !config.disabled)
48 );
49 const focuses = useMemo(
50 () => configs.map(config => focused[config.name] || false), //
51 [configs, focused]
52 );
54 // track whether or not input has been focused
55 const [hasBeenFocused, setHasBeenFocused] = useSetState({});
57 // build fn that transforms a value by input name
58 const transform = useCallback(
59 (name, value) => compose(...get(byName, [name, 'transformers'], []))(value),
60 [byName]
61 );
63 // build fn that validates a value by input name
64 const validate = useCallback(
65 (name, value) =>
66 compose(
67 ...get(byName, [name, 'validators'], []),
68 kDefaultValidator
69 )(value),
70 [byName]
71 );
73 // on change, transform and set value
74 const onChange = useCallback(
75 name => e => setValue(name, transform(name, e.target.value)), //
76 [setValue, transform]
77 );
78 // on focus, update focus
79 const onFocus = useCallback(
80 name => e => setFocused({ [name]: true }), //
81 [setFocused]
82 );
84 // on blur, defocus and set has been focused
85 const onBlur = useCallback(
86 name => e => {
87 setFocused({ [name]: false });
88 setHasBeenFocused({ [name]: false });
89 },
90 [setFocused, setHasBeenFocused]
91 );
93 // memo-compute validations of curent values
94 const validations = useMemo(
95 () => configs.map(config => validate(config.name, values[config.name])), //
96 [configs, validate, values]
97 );
99 // memo-compute the set of (perhaps changed by validation) data
100 const datas = useMemo(() => validations.map(v => v.data), [validations]);
102 // the input has errored if it
103 // 1) has been focused before
104 // 2)
105 // a) did not pass validation and has an error text
106 // b) or has a specific error from parent state
107 // (and we implicitly return the error text at the end)
108 const errors = useMemo(
109 () =>
110 configs.map(
111 (config, i) =>
112 hasBeenFocused[config.name] && //
113 (validations[i].error || config.error)
114 ),
115 [configs, validations, hasBeenFocused]
116 );
118 // this input has passed if
119 // 1) it has passed local validation
120 // 2) there are no errors
121 const passes = useMemo(
122 () => validations.map((v, i) => v.pass && !errors[i]),
123 [validations, errors]
124 );
126 // visibly tell the user that their input has passed if
127 // 1) they are or have interacted with the input before
128 // 2) and it has passed as defined above
129 const visiblePasses = useMemo(
130 () =>
131 configs.map(
132 (config, i) =>
133 (focused[config.name] || hasBeenFocused[config.name]) && //
134 passes[i]
135 ),
136 [configs, hasBeenFocused, focused, passes]
137 );
139 // generate the list of input states
140 const inputs = useMemo(
141 () =>
142 configs.map(
143 ({ name, error, autoFocus, disabled, initialValue, ...rest }, i) => ({
144 // Input props
145 name,
146 data: datas[i],
147 pass: passes[i],
148 visiblyPassed: visiblePasses[i],
149 error: errors[i],
150 focused: focuses[i],
151 autoFocus: autoFocus && !disabled,
152 disabled,
153 ...rest,
154 // dom properties below:
155 bind: {
156 value: values[name] || initialValue,
157 onChange: onChange(name),
158 onFocus: onFocus(name),
159 onBlur: onBlur(name),
160 autoFocus: autoFocus && !disabled,
161 },
162 })
163 ),
164 [
165 configs,
166 datas,
167 visiblePasses,
168 passes,
169 errors,
170 focuses,
171 values,
172 onBlur,
173 onChange,
174 onFocus,
175 ]
176 );
178 // did all of the inputs pass validation?
179 const pass = useMemo(() => every(passes), [passes]);
180 // did any of the inputs error?
181 const error = useMemo(() => some(errors), [errors]);
183 return {
184 inputs,
185 pass,
186 error,
187 };