73 lines
2.2 KiB
Markdown
73 lines
2.2 KiB
Markdown
---
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title: Textarea Interpolation is One-Way Only - Use v-model for Two-Way Binding
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impact: HIGH
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impactDescription: Using {{ text }} inside textarea displays initial value but user input does NOT update the ref
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type: capability
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tags: [vue3, v-model, forms, textarea, interpolation, template]
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---
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# Textarea Interpolation is One-Way Only - Use v-model for Two-Way Binding
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**Impact: HIGH** - Interpolation in textarea (`{{ text }}`) provides one-way binding only - it displays the initial value but user input does NOT update the ref. This creates a confusing disconnect where the textarea shows content but edits are silently lost.
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Unlike v-model which provides two-way binding, interpolation only renders the initial ref value into the textarea. When users type, the ref remains unchanged, making form submissions return stale data. Always use v-model for two-way binding in textareas.
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## Task Checklist
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- [ ] Never use interpolation inside textarea tags
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- [ ] Always use v-model for textarea two-way binding
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- [ ] Search codebase for `<textarea>{{` patterns that may be silently broken
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- [ ] Add linting rules to catch this pattern if possible
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**Incorrect:**
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```html
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<script setup>
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import { ref } from 'vue'
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const message = ref('Hello World')
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</script>
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<template>
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<!-- WRONG: One-way binding only! Shows initial value but edits don't update ref -->
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<textarea>{{ message }}</textarea>
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<!-- Also WRONG: User can type but changes are lost -->
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<textarea>{{ userBio }}</textarea>
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<!-- The textarea displays content but ref never updates -->
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</template>
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```
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**Correct:**
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```html
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<script setup>
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import { ref } from 'vue'
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const message = ref('Hello World')
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</script>
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<template>
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<!-- CORRECT: Use v-model for textarea -->
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<textarea v-model="message"></textarea>
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<!-- For read-only display, still use v-model or :value -->
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<textarea v-model="message" readonly></textarea>
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<!-- Or one-way binding with :value -->
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<textarea :value="message" readonly></textarea>
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</template>
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```
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```html
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<!-- With placeholder and other attributes -->
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<textarea
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v-model="message"
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placeholder="Enter your message..."
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rows="5"
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maxlength="500"
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></textarea>
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```
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## Reference
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- [Vue.js Form Input Bindings - Multiline text](https://vuejs.org/guide/essentials/forms.html#multiline-text)
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