XPages inputTextArea is not editable - xpages

Question

When i use multiLine editbox (shown in FIRST ONE) It cannot be editable If the document is in editMode.
But SECOND ONE is editable. My point is if use formula at the value of inputTextArea It can not be editable.
I could not find what it is that i missed?
FIRST ONE:
<xp:inputTextarea id="muvName" rows="2" cols="70"><xp:this.value><![CDATA[#{javascript:#Implode(document1.getItemValue("muvName"))+ #NewLine() + "C/o";}]]></xp:this.value></xp:inputTextarea>
SECOND ONE:
<xp:inputTextarea id="muvName" rows="2" cols="70" value="#{document1.muvName}">
</xp:inputTextarea>

Answer 1

Use the property defaultValue to define a default value:
<xp:inputTextarea
id="muvName"
rows="2"
cols="70"
value="#{document1.muvName}">
<xp:this.defaultValue><![CDATA[#{javascript:
#Implode(document1.muvName)+ #NewLine() + "C/o"
}]]></xp:this.defaultValue>
</xp:inputTextarea>
and use property value for binding a document's item (or a scope variable) to the editable field. value has to be an object to which XPage can write the submitted content to.
In your first example you calculate a string and it's impossible to write something back to a calculated string. That's why the field is read only.
Update:
If you want to correct document field's value before editing then use a custom converter instead:
<xp:inputTextarea
id="muvName"
rows="10"
cols="70"
value="#{document1.muvName}">
<xp:this.converter>
<xp:customConverter
getAsObject="#{javascript:value}">
<xp:this.getAsString><![CDATA[#{javascript:
if (!value.endsWith("C/o")) {
value += #NewLine() + "C/o";
}
value
}]]></xp:this.getAsString>
</xp:customConverter>
</xp:this.converter>
</xp:inputTextarea>